A subgroup of TRP cation channels that contain 3-4 ANKYRIN REPEAT DOMAINS and a conserved C-terminal domain. Members are highly expressed in the CENTRAL NERVOUS SYSTEM. Selectivity for calcium over sodium ranges from 0.5 to 10.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
A subgroup of TRP cation channels named after melastatin protein. They have the TRP domain but lack ANKYRIN repeats. Enzyme domains in the C-terminus leads to them being called chanzymes.
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.
A subgroup of TRP cation channels named after vanilloid receptor. They are very sensitive to TEMPERATURE and hot spicy food and CAPSAICIN. They have the TRP domain and ANKYRIN repeats. Selectivity for CALCIUM over SODIUM ranges from 3 to 100 fold.
The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.
Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.
A subgroup of cyclic nucleotide-regulated ION CHANNELS within the superfamily of pore-loop cation channels. They are expressed in OLFACTORY NERVE cilia and in PHOTORECEPTOR CELLS and some PLANTS.
A class of drugs that act by selective inhibition of calcium influx through cellular membranes.
Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.
A class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.
A broad group of eukaryotic six-transmembrane cation channels that are classified by sequence homology because their functional involvement with SENSATION is varied. They have only weak voltage sensitivity and ion selectivity. They are named after a DROSOPHILA mutant that displayed transient receptor potentials in response to light. A 25-amino-acid motif containing a TRP box (EWKFAR) just C-terminal to S6 is found in TRPC, TRPV and TRPM subgroups. ANKYRIN repeats are found in TRPC, TRPV & TRPN subgroups. Some are functionally associated with TYROSINE KINASE or TYPE C PHOSPHOLIPASES.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
An anthranilic acid derivative with analgesic, anti-inflammatory, and antipyretic properties. It is used in musculoskeletal and joint disorders and administered by mouth and topically. (From Martindale, The Extra Pharmacopoeia, 30th ed, p16)
Long-lasting voltage-gated CALCIUM CHANNELS found in both excitable and nonexcitable tissue. They are responsible for normal myocardial and vascular smooth muscle contractility. Five subunits (alpha-1, alpha-2, beta, gamma, and delta) make up the L-type channel. The alpha-1 subunit is the binding site for calcium-based antagonists. Dihydropyridine-based calcium antagonists are used as markers for these binding sites.
Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
A subgroup of TRP cation channels that are widely expressed in various cell types. Defects are associated with POLYCYSTIC KIDNEY DISEASES.
The ability of a substrate to allow the passage of ELECTRONS.
A family of proton-gated sodium channels that are primarily expressed in neuronal tissue. They are AMILORIDE-sensitive and are implicated in the signaling of a variety of neurological stimuli, most notably that of pain in response to acidic conditions.
Potassium channels whose activation is dependent on intracellular calcium concentrations.
Heteromultimers of Kir6 channels (the pore portion) and sulfonylurea receptor (the regulatory portion) which affect function of the HEART; PANCREATIC BETA CELLS; and KIDNEY COLLECTING DUCTS. KATP channel blockers include GLIBENCLAMIDE and mitiglinide whereas openers include CROMAKALIM and minoxidil sulfate.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
A class of drugs that act by inhibition of sodium influx through cell membranes. Blockade of sodium channels slows the rate and amplitude of initial rapid depolarization, reduces cell excitability, and reduces conduction velocity.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
Voltage-gated potassium channels whose primary subunits contain six transmembrane segments and form tetramers to create a pore with a voltage sensor. They are related to their founding member, shaker protein, Drosophila.
Sodium channels found on salt-reabsorbing EPITHELIAL CELLS that line the distal NEPHRON; the distal COLON; SALIVARY DUCTS; SWEAT GLANDS; and the LUNG. They are AMILORIDE-sensitive and play a critical role in the control of sodium balance, BLOOD VOLUME, and BLOOD PRESSURE.
The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
CALCIUM CHANNELS that are concentrated in neural tissue. Omega toxins inhibit the actions of these channels by altering their voltage dependence.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.
Established cell cultures that have the potential to propagate indefinitely.
A heterogenous group of transient or low voltage activated type CALCIUM CHANNELS. They are found in cardiac myocyte membranes, the sinoatrial node, Purkinje cells of the heart and the central nervous system.
Gadolinium. An element of the rare earth family of metals. It has the atomic symbol Gd, atomic number 64, and atomic weight 157.25. Its oxide is used in the control rods of some nuclear reactors.
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A subgroup of cyclic nucleotide-regulated ION CHANNELS of the superfamily of pore-loop cation channels that are opened by hyperpolarization rather than depolarization. The ion conducting pore passes SODIUM, CALCIUM, and POTASSIUM cations with a preference for potassium.
The rate dynamics in chemical or physical systems.
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Agents that increase calcium influx into calcium channels of excitable tissues. This causes vasoconstriction in VASCULAR SMOOTH MUSCLE and/or CARDIAC MUSCLE cells as well as stimulation of insulin release from pancreatic islets. Therefore, tissue-selective calcium agonists have the potential to combat cardiac failure and endocrinological disorders. They have been used primarily in experimental studies in cell and tissue culture.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
A family of voltage-gated potassium channels that are characterized by long N-terminal and C-terminal intracellular tails. They are named from the Drosophila protein whose mutation causes abnormal leg shaking under ether anesthesia. Their activation kinetics are dependent on extracellular MAGNESIUM and PROTON concentration.
A delayed rectifier subtype of shaker potassium channels that is selectively inhibited by a variety of SCORPION VENOMS.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
A delayed rectifier subtype of shaker potassium channels that is the predominant VOLTAGE-GATED POTASSIUM CHANNEL of T-LYMPHOCYTES.
A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.
Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.
Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
A delayed rectifier subtype of shaker potassium channels that conducts a delayed rectifier current. It contributes to ACTION POTENTIAL repolarization of MYOCYTES in HEART ATRIA.
A family of mechanosensitive sodium channels found primarily in NEMATODES where they play a role in CELLULAR MECHANOTRANSDUCTION. Degenerin sodium channels are structurally-related to EPITHELIAL SODIUM CHANNELS and are named after the fact that loss of their activity results in cellular degeneration.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Lanthanum. The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)
The relationship between the dose of an administered drug and the response of the organism to the drug.
A family of delayed rectifier voltage-gated potassium channels that share homology with their founding member, KCNQ1 PROTEIN. KCNQ potassium channels have been implicated in a variety of diseases including LONG QT SYNDROME; DEAFNESS; and EPILEPSY.
A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
A subfamily of shaker potassium channels that shares homology with its founding member, Shab protein, Drosophila. They regulate delayed rectifier currents in the NERVOUS SYSTEM of DROSOPHILA and in the SKELETAL MUSCLE and HEART of VERTEBRATES.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
A voltage-gated potassium channel that is expressed primarily in the HEART.
A family of proteins involved in the transport of organic cations. They play an important role in the elimination of a variety of endogenous substances, xenobiotics, and their metabolites from the body.
A major class of calcium-activated potassium channels that are found primarily in excitable CELLS. They play important roles in the transmission of ACTION POTENTIALS and generate a long-lasting hyperpolarization known as the slow afterhyperpolarization.
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
A sesquiterpene lactone found in roots of THAPSIA. It inhibits CA(2+)-TRANSPORTING ATPASE mediated uptake of CALCIUM into SARCOPLASMIC RETICULUM.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A subclass of purinergic P2 receptors that signal by means of a ligand-gated ion channel. They are comprised of three P2X subunits which can be identical (homotrimeric form) or dissimilar (heterotrimeric form).
An organic cation transporter found in kidney. It is localized to the basal lateral membrane and is likely to be involved in the renal secretion of organic cations.
A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.
Inorganic or organic compounds that contain boron as an integral part of the molecule.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
A tetrameric calcium release channel in the SARCOPLASMIC RETICULUM membrane of SMOOTH MUSCLE CELLS, acting oppositely to SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES. It is important in skeletal and cardiac excitation-contraction coupling and studied by using RYANODINE. Abnormalities are implicated in CARDIAC ARRHYTHMIAS and MUSCULAR DISEASES.
Diglycerides are a type of glyceride, specifically a form of lipid, that contains two fatty acid chains linked to a glycerol molecule by ester bonds.
Compounds based on an 8-membered heterocyclic ring including an oxygen. They can be considered medium ring ethers.
A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A widely distributed purinergic P2X receptor subtype that plays a role in pain sensation. P2X4 receptors found on MICROGLIA cells may also play a role in the mediation of allodynia-related NEUROPATHIC PAIN.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
A family of inwardly-rectifying potassium channels that are activated by PERTUSSIS TOXIN sensitive G-PROTEIN-COUPLED RECEPTORS. GIRK potassium channels are primarily activated by the complex of GTP-BINDING PROTEIN BETA SUBUNITS and GTP-BINDING PROTEIN GAMMA SUBUNITS.
Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Non-striated, elongated, spindle-shaped cells found lining the digestive tract, uterus, and blood vessels. They are derived from specialized myoblasts (MYOBLASTS, SMOOTH MUSCLE).
The pore-forming subunits of large-conductance calcium-activated potassium channels. They form tetramers in CELL MEMBRANES.
A fluorescent calcium chelating agent which is used to study intracellular calcium in tissues.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
A class of cell surface receptors for PURINES that prefer ATP or ADP over ADENOSINE. P2 purinergic receptors are widespread in the periphery and in the central and peripheral nervous system.
Proteins that bind specific drugs with high affinity and trigger intracellular changes influencing the behavior of cells. Drug receptors are generally thought to be receptors for some endogenous substance not otherwise specified.
Agents that affect ION PUMPS; ION CHANNELS; ABC TRANSPORTERS; and other MEMBRANE TRANSPORT PROTEINS.
A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.
Elements of limited time intervals, contributing to particular results or situations.
An inorganic dye used in microscopy for differential staining and as a diagnostic reagent. In research this compound is used to study changes in cytoplasmic concentrations of calcium. Ruthenium red inhibits calcium transport through membrane channels.
A purinergic P2X neurotransmitter receptor that plays a role in pain sensation signaling and regulation of inflammatory processes.
An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.
CALCIUM CHANNELS located within the PURKINJE CELLS of the cerebellum. They are involved in stimulation-secretion coupling of neurons.
An analgesic and anti-inflammatory agent used in the treatment of rheumatoid arthritis.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
A voltage-gated sodium channel subtype that mediates the sodium ion PERMEABILITY of CARDIOMYOCYTES. Defects in the SCN5A gene, which codes for the alpha subunit of this sodium channel, are associated with a variety of CARDIAC DISEASES that result from loss of sodium channel function.
A major class of calcium-activated potassium channels that were originally discovered in ERYTHROCYTES. They are found primarily in non-excitable CELLS and set up electrical gradients for PASSIVE ION TRANSPORT.
An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.
Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is closely related to KCNQ2 POTASSIUM CHANNEL. It is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN.
The nonstriated involuntary muscle tissue of blood vessels.
Proteins prepared by recombinant DNA technology.
An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.
An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.
Venoms from animals of the order Scorpionida of the class Arachnida. They contain neuro- and hemotoxins, enzymes, and various other factors that may release acetylcholine and catecholamines from nerve endings. Of the several protein toxins that have been characterized, most are immunogenic.
An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Cyclic nucleotides are closed-chain molecules formed from nucleotides (ATP or GTP) through the action of enzymes called cyclases, functioning as second messengers in various cellular signaling pathways, with cAMP and cGMP being the most prominent members.
CALCIUM CHANNELS located in the neurons of the brain.
A group of slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics they play an important role in controlling ACTION POTENTIAL duration.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.
A voltage-gated sodium channel subtype that mediates the sodium ion permeability of excitable membranes. Defects in the SCN2A gene which codes for the alpha subunit of this sodium channel are associated with benign familial infantile seizures type 3, and early infantile epileptic encephalopathy type 11.
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)
A purinergic P2X neurotransmitter receptor involved in sensory signaling of TASTE PERCEPTION, chemoreception, visceral distension and NEUROPATHIC PAIN. The receptor comprises three P2X2 subunits. The P2X2 subunits also have been found associated with P2X3 RECEPTOR subunits in a heterotrimeric receptor variant.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.
CALCIUM CHANNELS located in the neurons of the brain. They are inhibited by the marine snail toxin, omega conotoxin MVIIC.
Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.
Tetraethylammonium compounds refer to a group of organic salts containing the tetraethylammonium ion (N(C2H5)4+), which is characterized by four ethyl groups bonded to a central nitrogen atom, and are commonly used in research and medicine as pharmacological tools for studying ion channels.
The process by which cells convert mechanical stimuli into a chemical response. It can occur in both cells specialized for sensing mechanical cues such as MECHANORECEPTORS, and in parenchymal cells whose primary function is not mechanosensory.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Unsaturated derivatives of the ESTRANES with methyl groups at carbon-13, with no carbon at carbon-10, and with no more than one carbon at carbon-17. They must contain one or more double bonds.
Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.
Use of electric potential or currents to elicit biological responses.
A phosphoinositide present in all eukaryotic cells, particularly in the plasma membrane. It is the major substrate for receptor-stimulated phosphoinositidase C, with the consequent formation of inositol 1,4,5-triphosphate and diacylglycerol, and probably also for receptor-stimulated inositol phospholipid 3-kinase. (Kendrew, The Encyclopedia of Molecular Biology, 1994)
The physical characteristics and processes of biological systems.
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A non-steroidal anti-inflammatory agent with analgesic, anti-inflammatory, and antipyretic properties. It is an inhibitor of cyclooxygenase.
The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.
A variety of neuromuscular conditions resulting from MUTATIONS in ION CHANNELS manifesting as episodes of EPILEPSY; HEADACHE DISORDERS; and DYSKINESIAS.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
An alcohol produced from mint oils or prepared synthetically.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.
The quantity of volume or surface area of CELLS.
An inhibitor of anion conductance including band 3-mediated anion transport.
ATP-BINDING CASSETTE PROTEINS that are highly conserved and widely expressed in nature. They form an integral part of the ATP-sensitive potassium channel complex which has two intracellular nucleotide folds that bind to sulfonylureas and their analogs.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A family of membrane proteins that selectively conduct SODIUM ions due to changes in the TRANSMEMBRANE POTENTIAL DIFFERENCE. They typically have a multimeric structure with a core alpha subunit that defines the sodium channel subtype and several beta subunits that modulate sodium channel activity.
Drugs that bind to and activate cholinergic receptors.
A 37-amino acid residue peptide isolated from the scorpion Leiurus quinquestriatus hebraeus. It is a neurotoxin that inhibits calcium activated potassium channels.
A family of voltage-gated eukaryotic porins that form aqueous channels. They play an essential role in mitochondrial CELL MEMBRANE PERMEABILITY, are often regulated by BCL-2 PROTO-ONCOGENE PROTEINS, and have been implicated in APOPTOSIS.
An element with atomic symbol Cd, atomic number 48, and atomic weight 114. It is a metal and ingestion will lead to CADMIUM POISONING.
A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
Pyridine moieties which are partially saturated by the addition of two hydrogen atoms in any position.
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
A group of compounds that are derivatives of oxo-pyrrolidines. A member of this group is 2-oxo pyrrolidine, which is an intermediate in the manufacture of polyvinylpyrrolidone. (From Merck Index, 11th ed)
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal (MUSCLE FIBERS, SKELETAL), cardiac (MYOCYTES, CARDIAC), and smooth (MYOCYTES, SMOOTH MUSCLE). They are derived from embryonic (precursor) muscle cells called MYOBLASTS.
Elements of the lanthanoid series including atomic number 57 (LANTHANUM) through atomic number 71 (LUTETIUM).
A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.
Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.
The electrical properties, characteristics of living organisms, and the processes of organisms or their parts that are involved in generating and responding to electrical charges.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Search for oncogenic regulators in an autocrine tumor model using differential display PCR: identification of novel candidate genes including the calcium channel mtrp6. (1/1065)

A hemopoietic multistep tumor model, in which IL-3 dependent PB-3c mast cells, following expression of v-H-ras progress in vivo to IL-3 producing autocrine tumors has previously been established. Central for this oncogenic progression is a recessive step, which is reversible by cell fusion and leads to stabilization of IL-3 mRNA with concomitant activation of the autocrine loop. Comparing the IL-3 dependent PB-3c and the IL-3 autocrine V2D1 tumor cells with differential display PCR revealed 12 differentially expressed genes of which eight were upregulated and four downregulated in the tumor. They included four proteases (mouse mast cell protease 2, granzyme B, pepsinogen F and serine protease 1) and two metabolic enzymes (adenine phosphoribosyltransferase and fructose1,6-bisphosphatase). For validation, expression of the identified genes was tested in independent PB-3c precursor clones and their tumor derivatives. Expression of an endogenous retroviral IAP element and three unknown transcripts were consistently upregulated in all tumor lines. In somatic cell hybrids, two of these unknown cDNAs showed a dominant and one a recessive expression pattern. One transcript, expressed in the precursor but downregulated in the tumor cells, was cloned and identified as the murine calcium channel mtrp6.  (+info)

Mouse trp2, the homologue of the human trpc2 pseudogene, encodes mTrp2, a store depletion-activated capacitative Ca2+ entry channel. (2/1065)

Capacitative Ca2+ entry (CCE) is Ca2+ entering after stimulation of inositol 1,4,5-trisphosphate (IP3) formation and initiation of Ca2+ store depletion. One hallmark of CCE is that it can also be triggered merely by store depletion, as occurs after inhibition of internal Ca2+ pumps with thapsigargin. Evidence has accumulated in support of a role of transient receptor potential (Trp) proteins as structural subunits of a class of Ca2+-permeable cation channels activated by agonists that stimulate IP3 formation-very likely through a direct interaction between the IP3 receptor and a Trp subunit of the Ca2+ entry channel. The role of Trp's in Ca2+ entry triggered by store depletion alone is less clear. Only a few of the cloned Trp's appear to enhance this type of Ca2+ entry, and when they do, the effect requires special conditions to be observed, which native CCE does not. Here we report the full-length cDNA of mouse trp2, the homologue of the human trp2 pseudogene. Mouse Trp2 is shown to be readily activated not only after stimulation with an agonist but also by store depletion in the absence of an agonist. In contrast to other Trp proteins, Trp2-mediated Ca2+ entry activated by store depletion is seen under the same conditions that reveal endogenous store depletion-activated Ca2+ entry, i.e., classical CCE. The findings support the general hypothesis that Trp proteins are subunits of store- and receptor-operated Ca2+ channels.  (+info)

Specific association of the gene product of PKD2 with the TRPC1 channel. (3/1065)

The function(s) of the genes (PKD1 and PKD2) responsible for the majority of cases of autosomal dominant polycystic kidney disease is unknown. While PKD1 encodes a large integral membrane protein containing several structural motifs found in known proteins involved in cell-cell or cell-matrix interactions, PKD2 has homology to PKD1 and the major subunit of the voltage-activated Ca2+ channels. We now describe sequence homology between PKD2 and various members of the mammalian transient receptor potential channel (TRPC) proteins, thought to be activated by G protein-coupled receptor activation and/or depletion of internal Ca2+ stores. We show that PKD2 can directly associate with TRPC1 but not TRPC3 in transfected cells and in vitro. This association is mediated by two distinct domains in PKD2. One domain involves a minimal region of 73 amino acids in the C-terminal cytoplasmic tail of PKD2 shown previously to constitute an interacting domain with PKD1. However, distinct residues within this region mediate specific interactions with TRPC1 or PKD1. The C-terminal domain is sufficient but not necessary for the PKD2-TRPC1 association. A more N-terminal domain located within transmembrane segments S2 and S5, including a putative pore helical region between S5 and S6, is also responsible for the association. Given the ability of the TRPC to form functional homo- and heteromultimeric complexes, these data provide evidence that PKD2 may be functionally related to TRPC proteins and suggest a possible role of PKD2 in modulating Ca2+ entry in response to G protein-coupled receptor activation and/or store depletion.  (+info)

Cloning of Trp1beta isoform from rat brain: immunodetection and localization of the endogenous Trp1 protein. (4/1065)

The Trp gene product has been proposed as a candidate protein for the store-operated Ca2+ channel, but the Trp protein(s) has not been identified in any nonexcitable cell. We report here the cloning of a rat brain Trp1beta cDNA and detection and immunolocalization of the endogenous and expressed Trp1 protein. A 400-bp product, with >95% homology to mouse Trp1, was amplified from rat submandibular gland RNA. Rat-specific primers were used for cloning of a full-length rat brain Trp1beta cDNA (rTrp1), encoding a protein of 759 amino acids. Northern blot analysis demonstrated the transcript in several rat and mouse tissues. The peptide (amino acids 523-536) was used to generate a polyclonal antiserum. The affinity-purified antibody 1) immunoprecipitated human Trp1 (hTrp1) from transfected HEK-293 cells, 2) reacted with a protein of approximately 92 kDa, but not with hTrp3, in membranes of hTrp3-expressing HEK-293 cells, and 3) reacted with proteins of 92 and 56 kDa in human and rat brain membranes. Confocal microscopy and cell fractionation demonstrated that endogenous and expressed hTrp1 and expressed hTrp3 proteins were localized in the plasma membrane of HEK-293 cells, consistent with their proposed role in Ca2+ influx. The data demonstrate for the first time the presence of Trp1 protein in a nonexcitable cell.  (+info)

TRP2: a candidate transduction channel for mammalian pheromone sensory signaling. (5/1065)

The vomeronasal organ (VNO) of terrestrial vertebrates plays a key role in the detection of pheromones, chemicals released by animals that elicit stereotyped sexual and aggressive behaviors among conspecifics. Sensory transduction in the VNO appears unrelated to that in the vertebrate olfactory and visual systems: the putative pheromone receptors of the VNO are evolutionarily independent from the odorant receptors and, in contrast to vertebrate visual and olfactory transduction, vomeronasal transduction is unlikely to be mediated by cyclic-nucleotide-gated channels. We hypothesized that sensory transduction in the VNO might instead involve an ion channel of the transient receptor potential (TRP) family, members of which mediate cyclic-nucleotide-independent sensory responses in Drosophila melanogaster and Caenorhabditis elegans and play unknown functions in mammals. We have isolated a cDNA (rTRP2) from rat VNO encoding a protein of 885 amino acids that is equally distant from vertebrate and invertebrate TRP channels (10-30% amino acid identity). rTRP2 mRNA is exclusively expressed in VNO neurons, and the protein is highly localized to VNO sensory microvilli, the proposed site of pheromone sensory transduction. The absence of Ca2+ stores in sensory microvilli suggests that, in contrast to a proposed mechanism of activation of mammalian TRP channels, but in accord with analysis of TRP function in Drosophila phototransduction, the gating of TRP2 is independent from the depletion of internal Ca2+ stores. Thus, TRP2 is likely to participate in vomeronasal sensory transduction, which may share additional similarities with light-induced signaling in the Drosophila eye.  (+info)

Properties of heterologously expressed hTRP3 channels in bovine pulmonary artery endothelial cells. (6/1065)

1. We combined patch clamp and fura-2 fluorescence methods to characterize human TRP3 (hTRP3) channels heterologously expressed in cultured bovine pulmonary artery endothelial (CPAE) cells, which do not express the bovine trp3 isoform (btrp3) but express btrp1 and btrp4. 2. ATP, bradykinin and intracellular InsP3 activated a non-selective cation current (IhTRP3) in htrp3-transfected CPAE cells but not in non-transfected wild-type cells. During agonist stimulation, the sustained rise in [Ca2+]i was significantly higher in htrp3-transfected cells than in control CPAE cells. 3. The permeability for monovalent cations was PNa > PCs approximately PK >> PNMDG and the ratio PCa/PNa was 1.62 +/- 0.27 (n = 11). Removal of extracellular Ca2+ enhanced the amplitude of the agonist-activated IhTRP3 as well as that of the basal current The trivalent cations La3+ and Gd3+ were potent blockers of IhTRP3 (the IC50 for La3+ was 24.4 +/- 0.7 microM). 4. The single-channel conductance of the channels activated by ATP, assessed by noise analysis, was 23 pS. 5. Thapsigargin and 2,5-di-tert-butyl-1, 4-benzohydroquinone (BHQ), inhibitors of the organellar Ca2+-ATPase, failed to activate IhTRP3. U-73122, a phospholipase C blocker, inhibited IhTRP3 that had been activated by ATP and bradykinin. Thimerosal, an InsP3 receptor-sensitizing compound, enhanced IhTRP3, but calmidazolium, a calmodulin antagonist, did not affect IhTRP3. 6. It is concluded that hTRP3 forms non-selective plasmalemmal cation channels that function as a pathway for agonist-induced Ca2+ influx.  (+info)

Molecular and functional characterization of a novel mouse transient receptor potential protein homologue TRP7. Ca(2+)-permeable cation channel that is constitutively activated and enhanced by stimulation of G protein-coupled receptor. (7/1065)

Characterization of mammalian homologues of Drosophila transient receptor potential protein (TRP) is an important clue to understand molecular mechanisms underlying Ca(2+) influx activated in response to stimulation of G(q) protein-coupled receptors in vertebrate cells. Here we have isolated cDNA encoding a novel seventh mammalian TRP homologue, TRP7, from mouse brain. TRP7 showed abundant RNA expression in the heart, lung, and eye and moderate expression in the brain, spleen, and testis. TRP7 recombinantly expressed in human embryonic kidney cells exhibited distinctive functional features, compared with other TRP homologues. Basal influx activity accompanied by reduction in Ca(2+) release from internal stores was characteristic of TRP7-expressing cells but was by far less significant in cells expressing TRP3, which is structurally the closest to TRP7 in the TRP family. TRP7 induced Ca(2+) influx in response to ATP receptor stimulation at ATP concentrations lower than those necessary for activation of TRP3 and for Ca(2+) release from the intracellular store, which suggests that the TRP7 channel is activated independently of Ca(2+) release. In fact, TRP7 expression did not affect capacitative Ca(2+) entry induced by thapsigargin, whereas TRP7 greatly potentiated Mn(2+) influx induced by diacylglycerols without involvement of protein kinase C. Nystatin-perforated and conventional whole-cell patch clamp recordings from TRP7-expressing cells demonstrated the constitutively activated and ATP-enhanced inward cation currents, both of which were initially blocked and then subsequently facilitated by extracellular Ca(2+) at a physiological concentration. Impairment of TRP7 currents by internal perfusion of the Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid revealed an essential role of intracellular Ca(2+) in activation of TRP7, and their potent activation by the diacylglycerol analogue suggests that the TRP7 channel is a new member of diacylglycerol-activated cation channels. Relative permeabilities indicate that TRP7 is slightly selective to divalent cations. Thus, our findings reveal an interesting correspondence of TRP7 to the background and receptor stimulation-induced cation currents in various native systems.  (+info)

The N-terminal domain of the IP3 receptor gates store-operated hTrp3 channels. (8/1065)

In the present work, we studied the interaction and effect of several IP3 receptor (IP3R) constructs on the gating of the store-operated (SOC) hTrp3 channel. Full-length IP3R coupled to silent hTrp3 channels in intact cells but did not activate them until stores were depleted of Ca2+. By contrast, constructs containing the IP3-binding domain activated silent hTrp3 channels in unstimulated cells and restored gating of hTrp3 by IP3 in excised plasma membrane patches. We conclude that the N-terminal domain of the IP3R functions as a gate and is sufficient for activation of SOCs. The sensing and transduction domains of the IP3R are required to maintain SOCs in an inactive state.  (+info)

Transient Receptor Potential Canonical (TRPC) cation channels are a subfamily of the TRP superfamily of non-selective cation channels. They are widely expressed in various tissues and play crucial roles in many cellular processes, including sensory perception, cell proliferation, and migration. TRPC channels are permeable to both monovalent (sodium and potassium) and divalent (calcium and magnesium) cations, and their activation can lead to a rise in intracellular calcium concentration, which in turn regulates various downstream signaling pathways. TRPC channels can be activated by a variety of stimuli, including G protein-coupled receptors, receptor tyrosine kinases, and mechanical stress. Mutations in TRPC genes have been associated with several human diseases, including hereditary hearing loss, cardiovascular disorders, and neurological conditions.

A cation is a type of ion, which is a charged particle, that has a positive charge. In chemistry and biology, cations are formed when a neutral atom loses one or more electrons during chemical reactions. The removal of electrons results in the atom having more protons than electrons, giving it a net positive charge.

Cations are important in many biological processes, including nerve impulse transmission, muscle contraction, and enzyme function. For example, sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) are all essential cations that play critical roles in various physiological functions.

In medical contexts, cations can also be relevant in the diagnosis and treatment of various conditions. For instance, abnormal levels of certain cations, such as potassium or calcium, can indicate specific diseases or disorders. Additionally, medications used to treat various conditions may work by altering cation concentrations or activity within the body.

Ion channels are specialized transmembrane proteins that form hydrophilic pores or gaps in the lipid bilayer of cell membranes. They regulate the movement of ions (such as sodium, potassium, calcium, and chloride) across the cell membrane by allowing these charged particles to pass through selectively in response to various stimuli, including voltage changes, ligand binding, mechanical stress, or temperature changes. This ion movement is essential for many physiological processes, including electrical signaling, neurotransmission, muscle contraction, and maintenance of resting membrane potential. Ion channels can be categorized based on their activation mechanisms, ion selectivity, and structural features. Dysfunction of ion channels can lead to various diseases, making them important targets for drug development.

Transient Receptor Potential Melastatin (TRPM) cation channels are a subfamily of the transient receptor potential (TRP) channel superfamily, which are non-selective cation channels that play important roles in various cellular processes such as sensory perception, cell proliferation, and migration.

The TRPM subfamily consists of eight members (TRPM1-8), each with distinct functional properties and expression patterns. These channels are permeable to both monovalent and divalent cations, including calcium (Ca^2+^) and magnesium (Mg^2+^).

TRPM channels can be activated by a variety of stimuli, such as changes in temperature, voltage, osmolarity, and chemical ligands. For example, TRPM8 is known to be activated by cold temperatures and menthol, while TRPV1 is activated by heat and capsaicin.

Dysregulation of TRPM channels has been implicated in various pathological conditions, including pain, neurodegenerative diseases, and cancer. Therefore, understanding the structure and function of these channels may provide insights into potential therapeutic targets for these conditions.

Calcium channels are specialized proteins that span the membrane of cells and allow calcium ions (Ca²+) to flow in and out of the cell. They are crucial for many physiological processes, including muscle contraction, neurotransmitter release, hormone secretion, and gene expression.

There are several types of calcium channels, classified based on their biophysical and pharmacological properties. The most well-known are:

1. Voltage-gated calcium channels (VGCCs): These channels are activated by changes in the membrane potential. They are further divided into several subtypes, including L-type, P/Q-type, N-type, R-type, and T-type. VGCCs play a critical role in excitation-contraction coupling in muscle cells and neurotransmitter release in neurons.
2. Receptor-operated calcium channels (ROCCs): These channels are activated by the binding of an extracellular ligand, such as a hormone or neurotransmitter, to a specific receptor on the cell surface. ROCCs are involved in various physiological processes, including smooth muscle contraction and platelet activation.
3. Store-operated calcium channels (SOCCs): These channels are activated by the depletion of intracellular calcium stores, such as those found in the endoplasmic reticulum. SOCCs play a critical role in maintaining calcium homeostasis and signaling within cells.

Dysregulation of calcium channel function has been implicated in various diseases, including hypertension, arrhythmias, migraine, epilepsy, and neurodegenerative disorders. Therefore, calcium channels are an important target for drug development and therapy.

Transient receptor potential vanilloid (TRPV) cation channels are a subfamily of transient receptor potential (TRP) channels, which are non-selective cation channels that play important roles in various physiological processes such as nociception, thermosensation, and mechanosensation. TRPV channels are activated by a variety of stimuli including temperature, chemical ligands, and mechanical forces.

TRPV channels are composed of six transmembrane domains with intracellular N- and C-termini. The TRPV subfamily includes six members: TRPV1 to TRPV6. Among them, TRPV1 is also known as the vanilloid receptor 1 (VR1) and is activated by capsaicin, the active component of hot chili peppers, as well as noxious heat. TRPV2 is activated by noxious heat and mechanical stimuli, while TRPV3 and TRPV4 are activated by warm temperatures and various chemical ligands. TRPV5 and TRPV6 are primarily involved in calcium transport and are activated by low pH and divalent cations.

TRPV channels play important roles in pain sensation, neurogenic inflammation, and temperature perception. Dysfunction of these channels has been implicated in various pathological conditions such as chronic pain, inflammatory diseases, and cancer. Therefore, TRPV channels are considered promising targets for the development of novel therapeutics for these conditions.

Ion channel gating refers to the process by which ion channels in cell membranes open and close in response to various stimuli, allowing ions such as sodium, potassium, and calcium to flow into or out of the cell. This movement of ions is crucial for many physiological processes, including the generation and transmission of electrical signals in nerve cells, muscle contraction, and the regulation of hormone secretion.

Ion channel gating can be regulated by various factors, including voltage changes across the membrane (voltage-gated channels), ligand binding (ligand-gated channels), mechanical stress (mechanosensitive channels), or other intracellular signals (second messenger-gated channels). The opening and closing of ion channels are highly regulated and coordinated processes that play a critical role in maintaining the proper functioning of cells and organ systems.

Divalent cations are ions that carry a positive charge of +2. They are called divalent because they have two positive charges. Common examples of divalent cations include calcium (Ca²+), magnesium (Mg²+), and iron (Fe²+). These ions play important roles in various biological processes, such as muscle contraction, nerve impulse transmission, and bone metabolism. They can also interact with certain drugs and affect their absorption, distribution, and elimination in the body.

Inwardly rectifying potassium channels (Kir) are a type of potassium channel that allow for the selective passage of potassium ions (K+) across cell membranes. The term "inwardly rectifying" refers to their unique property of allowing potassium ions to flow more easily into the cell (inward current) than out of the cell (outward current). This characteristic is due to the voltage-dependent blockage of these channels by intracellular magnesium and polyamines at depolarized potentials.

These channels play crucial roles in various physiological processes, including:

1. Resting membrane potential maintenance: Kir channels help establish and maintain the negative resting membrane potential in cells by facilitating potassium efflux when the membrane potential is near the potassium equilibrium potential (Ek).
2. Action potential repolarization: In excitable cells like neurons and muscle fibers, Kir channels contribute to the rapid repolarization phase of action potentials, allowing for proper electrical signaling.
3. Cell volume regulation: Kir channels are involved in regulating cell volume by mediating potassium influx during osmotic stress or changes in intracellular ion concentrations.
4. Insulin secretion: In pancreatic β-cells, Kir channels control the membrane potential and calcium signaling necessary for insulin release.
5. Renal function: Kir channels are essential for maintaining electrolyte balance and controlling renal tubular transport in the kidneys.

There are several subfamilies of inwardly rectifying potassium channels (Kir1-7), each with distinct biophysical properties, tissue distributions, and functions. Mutations in genes encoding these channels can lead to various human diseases, including cardiac arrhythmias, epilepsy, and Bartter syndrome.

Cyclic nucleotide-gated (CNG) channels are a type of ion channel found in the membranes of certain cells, particularly in the sensory neurons of the visual and olfactory systems. They are called cyclic nucleotide-gated because they can be activated or regulated by the binding of cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP) or cyclic guanosine monophosphate (cGMP), to the intracellular domain of the channel.

CNG channels are permeable to cations, including sodium (Na+) and calcium (Ca2+) ions, and their activation allows these ions to flow into the cell. This influx of cations can trigger a variety of cellular responses, such as the initiation of visual or olfactory signaling pathways.

CNG channels are composed of four subunits that form a functional channel. Each subunit has a cyclic nucleotide-binding domain (CNBD) in its intracellular region, which can bind to cyclic nucleotides and regulate the opening and closing of the channel. The CNBD is connected to the pore-forming region of the channel by a flexible linker, allowing for conformational changes in the CNBD to be transmitted to the pore and modulate ion conductance.

CNG channels play important roles in various physiological processes, including sensory perception, neurotransmission, and cellular signaling. Dysfunction of CNG channels has been implicated in several human diseases, such as retinitis pigmentosa, congenital stationary night blindness, and cystic fibrosis.

Calcium channel blockers (CCBs) are a class of medications that work by inhibiting the influx of calcium ions into cardiac and smooth muscle cells. This action leads to relaxation of the muscles, particularly in the blood vessels, resulting in decreased peripheral resistance and reduced blood pressure. Calcium channel blockers also have anti-arrhythmic effects and are used in the management of various cardiovascular conditions such as hypertension, angina, and certain types of arrhythmias.

Calcium channel blockers can be further classified into two main categories based on their chemical structure: dihydropyridines (e.g., nifedipine, amlodipine) and non-dihydropyridines (e.g., verapamil, diltiazem). Dihydropyridines are more selective for vascular smooth muscle and have a greater effect on blood pressure than heart rate or conduction. Non-dihydropyridines have a more significant impact on cardiac conduction and contractility, in addition to their vasodilatory effects.

It is important to note that calcium channel blockers may interact with other medications and should be used under the guidance of a healthcare professional. Potential side effects include dizziness, headache, constipation, and peripheral edema.

A monovalent cation is a type of ion that has a single positive charge. In the context of medical and biological sciences, monovalent cations are important because they play crucial roles in various physiological processes, such as maintaining electrical neutrality in cells, facilitating nerve impulse transmission, and regulating fluid balance.

The most common monovalent cation is sodium (Na+), which is the primary cation in the extracellular fluid. Other examples of monovalent cations include potassium (K+), which is the main cation inside cells, and hydrogen (H+) ions, which are involved in acid-base balance.

Monovalent cations are typically measured in milliequivalents per liter (mEq/L) in clinical settings to express their concentration in biological fluids.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Chloride channels are membrane proteins that form hydrophilic pores or gaps, allowing the selective passage of chloride ions (Cl-) across the lipid bilayer of cell membranes. They play crucial roles in various physiological processes, including regulation of neuronal excitability, maintenance of resting membrane potential, fluid and electrolyte transport, and pH and volume regulation of cells.

Chloride channels can be categorized into several groups based on their structure, function, and mechanism of activation. Some of the major classes include:

1. Voltage-gated chloride channels (ClC): These channels are activated by changes in membrane potential and have a variety of functions, such as regulating neuronal excitability and transepithelial transport.
2. Ligand-gated chloride channels: These channels are activated by the binding of specific ligands or messenger molecules, like GABA (gamma-aminobutyric acid) or glycine, and are involved in neurotransmission and neuromodulation.
3. Cystic fibrosis transmembrane conductance regulator (CFTR): This is a chloride channel primarily located in the apical membrane of epithelial cells, responsible for secreting chloride ions and water to maintain proper hydration and mucociliary clearance in various organs, including the lungs and pancreas.
4. Calcium-activated chloride channels (CaCCs): These channels are activated by increased intracellular calcium concentrations and participate in various physiological processes, such as smooth muscle contraction, neurotransmitter release, and cell volume regulation.
5. Swelling-activated chloride channels (ClSwells): Also known as volume-regulated anion channels (VRACs), these channels are activated by cell swelling or osmotic stress and help regulate cell volume and ionic homeostasis.

Dysfunction of chloride channels has been implicated in various human diseases, such as cystic fibrosis, myotonia congenita, epilepsy, and certain forms of cancer.

Potassium channel blockers are a class of medications that work by blocking potassium channels, which are proteins in the cell membrane that control the movement of potassium ions into and out of cells. By blocking these channels, potassium channel blockers can help to regulate electrical activity in the heart, making them useful for treating certain types of cardiac arrhythmias (irregular heart rhythms).

There are several different types of potassium channel blockers, including:

1. Class III antiarrhythmic drugs: These medications, such as amiodarone and sotalol, are used to treat and prevent serious ventricular arrhythmias (irregular heart rhythms that originate in the lower chambers of the heart).
2. Calcium channel blockers: While not strictly potassium channel blockers, some calcium channel blockers also have effects on potassium channels. These medications, such as diltiazem and verapamil, are used to treat hypertension (high blood pressure), angina (chest pain), and certain types of arrhythmias.
3. Non-selective potassium channel blockers: These medications, such as 4-aminopyridine and tetraethylammonium, have a broader effect on potassium channels and are used primarily in research settings to study the electrical properties of cells.

It's important to note that potassium channel blockers can have serious side effects, particularly when used in high doses or in combination with other medications that affect heart rhythms. They should only be prescribed by a healthcare provider who is familiar with their use and potential risks.

Transient receptor potential (TRP) channels are a type of ion channel proteins that are widely expressed in various tissues and cells, including the sensory neurons, epithelial cells, and immune cells. They are named after the transient receptor potential mutant flies, which have defects in light-induced electrical responses due to mutations in TRP channels.

TRP channels are polymodal signal integrators that can be activated by a diverse range of physical and chemical stimuli, such as temperature, pressure, touch, osmolarity, pH, and various endogenous and exogenous ligands. Once activated, TRP channels allow the flow of cations, including calcium (Ca2+), sodium (Na+), and magnesium (Mg2+) ions, across the cell membrane.

TRP channels play critical roles in various physiological processes, such as sensory perception, neurotransmission, muscle contraction, cell proliferation, differentiation, migration, and apoptosis. Dysfunction of TRP channels has been implicated in a variety of pathological conditions, including pain, inflammation, neurodegenerative diseases, cardiovascular diseases, metabolic disorders, and cancer.

There are six subfamilies of TRP channels, based on their sequence homology and functional properties: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPP (polycystin), and TRPML (mucolipin). Each subfamily contains several members with distinct activation mechanisms, ion selectivity, and tissue distribution.

In summary, Transient Receptor Potential Channels are a group of polymodal cation channels that play critical roles in various physiological processes and are implicated in many pathological conditions.

Patch-clamp techniques are a group of electrophysiological methods used to study ion channels and other electrical properties of cells. These techniques were developed by Erwin Neher and Bert Sakmann, who were awarded the Nobel Prize in Physiology or Medicine in 1991 for their work. The basic principle of patch-clamp techniques involves creating a high resistance seal between a glass micropipette and the cell membrane, allowing for the measurement of current flowing through individual ion channels or groups of channels.

There are several different configurations of patch-clamp techniques, including:

1. Cell-attached configuration: In this configuration, the micropipette is attached to the outer surface of the cell membrane, and the current flowing across a single ion channel can be measured. This configuration allows for the study of the properties of individual channels in their native environment.
2. Whole-cell configuration: Here, the micropipette breaks through the cell membrane, creating a low resistance electrical connection between the pipette and the inside of the cell. This configuration allows for the measurement of the total current flowing across all ion channels in the cell membrane.
3. Inside-out configuration: In this configuration, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the inner surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in isolation from other cellular components.
4. Outside-out configuration: Here, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the outer surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in their native environment, but with the ability to control the composition of the extracellular solution.

Patch-clamp techniques have been instrumental in advancing our understanding of ion channel function and have contributed to numerous breakthroughs in neuroscience, pharmacology, and physiology.

Membrane potential is the electrical potential difference across a cell membrane, typically for excitable cells such as nerve and muscle cells. It is the difference in electric charge between the inside and outside of a cell, created by the selective permeability of the cell membrane to different ions. The resting membrane potential of a typical animal cell is around -70 mV, with the interior being negative relative to the exterior. This potential is generated and maintained by the active transport of ions across the membrane, primarily through the action of the sodium-potassium pump. Membrane potentials play a crucial role in many physiological processes, including the transmission of nerve impulses and the contraction of muscle cells.

Flufenamic Acid is a type of non-steroidal anti-inflammatory drug (NSAID) that is used to relieve pain, reduce inflammation, and lower fever. It works by blocking the action of certain enzymes in the body, such as cyclooxygenase (COX), which are involved in producing substances that cause pain and inflammation. Flufenamic Acid is available in various forms, including tablets, capsules, and suppositories, and is used to treat a variety of conditions, such as menstrual cramps, arthritis, and muscle or bone injuries. It is important to note that like all NSAIDs, Flufenamic Acid can have side effects, particularly if taken in large doses or for long periods of time, so it should be used only under the supervision of a healthcare provider.

Calcium channels, L-type, are a type of voltage-gated calcium channel that are widely expressed in many excitable cells, including cardiac and skeletal muscle cells, as well as certain neurons. These channels play a crucial role in the regulation of various cellular functions, such as excitation-contraction coupling, hormone secretion, and gene expression.

L-type calcium channels are composed of five subunits: alpha-1, alpha-2, beta, gamma, and delta. The alpha-1 subunit is the pore-forming subunit that contains the voltage sensor and the selectivity filter for calcium ions. It has four repeated domains (I-IV), each containing six transmembrane segments (S1-S6). The S4 segment in each domain functions as a voltage sensor, moving outward upon membrane depolarization to open the channel and allow calcium ions to flow into the cell.

L-type calcium channels are activated by membrane depolarization and have a relatively slow activation and inactivation time course. They are also modulated by various intracellular signaling molecules, such as protein kinases and G proteins. L-type calcium channel blockers, such as nifedipine and verapamil, are commonly used in the treatment of hypertension, angina, and certain cardiac arrhythmias.

Voltage-gated potassium channels are a type of ion channel found in the membrane of excitable cells such as nerve and muscle cells. They are called "voltage-gated" because their opening and closing is regulated by the voltage, or electrical potential, across the cell membrane. Specifically, these channels are activated when the membrane potential becomes more positive, a condition that occurs during the action potential of a neuron or muscle fiber.

When voltage-gated potassium channels open, they allow potassium ions (K+) to flow out of the cell down their electrochemical gradient. This outward flow of K+ ions helps to repolarize the membrane, bringing it back to its resting potential after an action potential has occurred. The precise timing and duration of the opening and closing of voltage-gated potassium channels is critical for the normal functioning of excitable cells, and abnormalities in these channels have been linked to a variety of diseases, including cardiac arrhythmias, epilepsy, and neurological disorders.

Electrophysiology is a branch of medicine that deals with the electrical activities of the body, particularly the heart. In a medical context, electrophysiology studies (EPS) are performed to assess abnormal heart rhythms (arrhythmias) and to evaluate the effectiveness of certain treatments, such as medication or pacemakers.

During an EPS, electrode catheters are inserted into the heart through blood vessels in the groin or neck. These catheters can record the electrical activity of the heart and stimulate it to help identify the source of the arrhythmia. The information gathered during the study can help doctors determine the best course of treatment for each patient.

In addition to cardiac electrophysiology, there are also other subspecialties within electrophysiology, such as neuromuscular electrophysiology, which deals with the electrical activity of the nervous system and muscles.

Transient Receptor Potential (TRP) channels are a type of ion channel that play a crucial role in various physiological processes, including sensory perception, cellular signaling, and regulation of intracellular calcium levels. TRPP cation channels, also known as TRPP subfamily or polycystin channels, are a specific subgroup within the TRP channel family.

TRPP channels consist of two members: TRPP1 (also known as PKD1 or polycystin-1) and TRPP2 (also known as PKD2 or polycystin-2). These channels form heterodimers, meaning they are composed of two different subunits that come together to create a functional channel.

TRPP channels are primarily located in the primary cilium, a hair-like structure protruding from the cell surface, and in the endoplasmic reticulum (ER), an intracellular organelle involved in protein folding and calcium storage. They function as mechano- and chemosensors, responding to various stimuli such as mechanical forces, changes in temperature, pH, or chemical ligands.

TRPP channels are particularly important in the context of renal physiology and pathophysiology. Mutations in TRPP1 and TRPP2 have been linked to autosomal dominant polycystic kidney disease (ADPKD), a genetic disorder characterized by the formation of fluid-filled cysts in the kidneys, leading to progressive loss of renal function.

In summary, TRPP cation channels are a subfamily of TRP channels formed by the heterodimerization of TRPP1 and TRPP2 subunits. They play essential roles in sensory perception, cellular signaling, and calcium homeostasis, with particular significance in renal physiology and pathophysiology.

Electric conductivity, also known as electrical conductance, is a measure of a material's ability to allow the flow of electric current through it. It is usually measured in units of Siemens per meter (S/m) or ohm-meters (Ω-m).

In medical terms, electric conductivity can refer to the body's ability to conduct electrical signals, which is important for various physiological processes such as nerve impulse transmission and muscle contraction. Abnormalities in electrical conductivity can be associated with various medical conditions, including neurological disorders and heart diseases.

For example, in electrocardiography (ECG), the electric conductivity of the heart is measured to assess its electrical activity and identify any abnormalities that may indicate heart disease. Similarly, in electromyography (EMG), the electric conductivity of muscles is measured to diagnose neuromuscular disorders.

Acid-sensing ion channels (ASICs) are a type of ion channel protein found in nerve cells (neurons) that are activated by acidic environments. They are composed of homomeric or heteromeric combinations of six different subunits, designated ASIC1a, ASIC1b, ASIC2a, ASIC2b, ASIC3, and ASIC4. These channels play important roles in various physiological processes, including pH homeostasis, nociception (pain perception), and mechanosensation (the ability to sense mechanical stimuli).

ASICs are permeable to both sodium (Na+) and calcium (Ca2+) ions. When the extracellular pH decreases, the channels open, allowing Na+ and Ca2+ ions to flow into the neuron. This influx of cations can depolarize the neuronal membrane, leading to the generation of action potentials and neurotransmitter release.

In the context of pain perception, ASICs are activated by the acidic environment in damaged tissues or ischemic conditions, contributing to the sensation of pain. In addition, some ASIC subunits have been implicated in synaptic plasticity, learning, and memory processes. Dysregulation of ASIC function has been associated with various pathological conditions, including neuropathic pain, ischemia, epilepsy, and neurodegenerative diseases.

Calcium-activated potassium channels are a type of ion channel found in the membranes of cells. These channels are activated by an increase in intracellular calcium levels and play a crucial role in regulating various cellular processes, including electrical excitability, neurotransmitter release, hormone secretion, and vascular tone.

Once activated, calcium-activated potassium channels allow potassium ions (K+) to flow out of the cell, which can lead to membrane hyperpolarization or stabilization of the resting membrane potential. This process helps control the frequency and duration of action potentials in excitable cells such as neurons and muscle fibers.

There are several subtypes of calcium-activated potassium channels, including:

1. Large conductance calcium-activated potassium (BK) channels: These channels have a large single-channel conductance and are activated by both voltage and intracellular calcium. They play essential roles in regulating vascular tone, neurotransmitter release, and neuronal excitability.
2. Small conductance calcium-activated potassium (SK) channels: These channels have a smaller single-channel conductance and are primarily activated by intracellular calcium. They contribute to the regulation of neuronal excitability and neurotransmitter release.
3. Intermediate conductance calcium-activated potassium (IK) channels: These channels have an intermediate single-channel conductance and are activated by both voltage and intracellular calcium. They play a role in regulating epithelial ion transport, smooth muscle cell excitability, and neurotransmitter release.

Dysfunction of calcium-activated potassium channels has been implicated in various pathological conditions, such as hypertension, epilepsy, chronic pain, and neurological disorders.

ATP-sensitive potassium (KATP) channels are a type of ion channel found in the membranes of cells, including those in the heart, muscle, and pancreas. These channels are unique because their opening and closing are regulated by the levels of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) in the cell.

Under normal conditions, when ATP levels are high and ADP levels are low, the KATP channels are closed, which allows the cells to maintain their normal electrical activity. However, during times of metabolic stress or ischemia (a lack of blood flow), the levels of ATP in the cell decrease while the levels of ADP increase. This change in the ATP-to-ADP ratio causes the KATP channels to open, which allows potassium ions to flow out of the cell. The efflux of potassium ions then leads to hyperpolarization of the cell membrane, which helps to protect the cells from damage.

In the pancreas, KATP channels play a crucial role in regulating insulin secretion. In the beta cells of the pancreas, an increase in blood glucose levels leads to an increase in ATP production and a decrease in ADP levels, which causes the KATP channels to close. This closure of the KATP channels leads to depolarization of the cell membrane, which triggers the release of insulin.

Overall, KATP channels are important regulators of cellular electrical activity and play a critical role in protecting cells from damage during times of metabolic stress or ischemia.

Potassium is a essential mineral and an important electrolyte that is widely distributed in the human body. The majority of potassium in the body (approximately 98%) is found within cells, with the remaining 2% present in blood serum and other bodily fluids. Potassium plays a crucial role in various physiological processes, including:

1. Regulation of fluid balance and maintenance of normal blood pressure through its effects on vascular tone and sodium excretion.
2. Facilitation of nerve impulse transmission and muscle contraction by participating in the generation and propagation of action potentials.
3. Protein synthesis, enzyme activation, and glycogen metabolism.
4. Regulation of acid-base balance through its role in buffering systems.

The normal serum potassium concentration ranges from 3.5 to 5.0 mEq/L (milliequivalents per liter) or mmol/L (millimoles per liter). Potassium levels outside this range can have significant clinical consequences, with both hypokalemia (low potassium levels) and hyperkalemia (high potassium levels) potentially leading to serious complications such as cardiac arrhythmias, muscle weakness, and respiratory failure.

Potassium is primarily obtained through the diet, with rich sources including fruits (e.g., bananas, oranges, and apricots), vegetables (e.g., leafy greens, potatoes, and tomatoes), legumes, nuts, dairy products, and meat. In cases of deficiency or increased needs, potassium supplements may be recommended under the guidance of a healthcare professional.

Sodium channel blockers are a class of medications that work by blocking sodium channels in the heart, which prevents the rapid influx of sodium ions into the cells during depolarization. This action slows down the rate of impulse generation and propagation in the heart, which in turn decreases the heart rate and prolongs the refractory period.

Sodium channel blockers are primarily used to treat cardiac arrhythmias, including atrial fibrillation, atrial flutter, and ventricular tachycardia. They may also be used to treat certain types of neuropathic pain. Examples of sodium channel blockers include Class I antiarrhythmics such as flecainide, propafenone, lidocaine, and mexiletine.

It's important to note that sodium channel blockers can have potential side effects, including proarrhythmia (i.e., the development of new arrhythmias or worsening of existing ones), negative inotropy (decreased contractility of the heart muscle), and cardiac conduction abnormalities. Therefore, these medications should be used with caution and under the close supervision of a healthcare provider.

Sodium is an essential mineral and electrolyte that is necessary for human health. In a medical context, sodium is often discussed in terms of its concentration in the blood, as measured by serum sodium levels. The normal range for serum sodium is typically between 135 and 145 milliequivalents per liter (mEq/L).

Sodium plays a number of important roles in the body, including:

* Regulating fluid balance: Sodium helps to regulate the amount of water in and around your cells, which is important for maintaining normal blood pressure and preventing dehydration.
* Facilitating nerve impulse transmission: Sodium is involved in the generation and transmission of electrical signals in the nervous system, which is necessary for proper muscle function and coordination.
* Assisting with muscle contraction: Sodium helps to regulate muscle contractions by interacting with other minerals such as calcium and potassium.

Low sodium levels (hyponatremia) can cause symptoms such as confusion, seizures, and coma, while high sodium levels (hypernatremia) can lead to symptoms such as weakness, muscle cramps, and seizures. Both conditions require medical treatment to correct.

The Shaker superfamily of potassium channels, also known as Kv channels (voltage-gated potassium channels), refers to a group of ion channels that are responsible for the selective transport of potassium ions across the cell membrane. These channels are crucial for regulating the electrical excitability of cells, particularly in neurons and muscle cells.

The Shaker superfamily is named after the Drosophila melanogaster (fruit fly) gene shaker, which was the first voltage-gated potassium channel to be identified and cloned. The channels in this family share a common structure, consisting of four subunits that each contain six transmembrane domains. The fourth domain contains the voltage sensor, which responds to changes in membrane potential and triggers the opening or closing of the channel pore.

The Shaker superfamily is further divided into several subfamilies based on their sequence similarity and functional properties. These include the Shaw, Shab, and Shal subfamilies, among others. Each subfamily has distinct biophysical and pharmacological properties that allow for selective activation or inhibition by various drugs and toxins.

Overall, the Shaker superfamily of potassium channels plays a critical role in maintaining the electrical excitability of cells and is involved in a wide range of physiological processes, including nerve impulse transmission, muscle contraction, and hormone secretion.

Epithelial Sodium Channels (ENaC) are a type of ion channel found in the epithelial cells that line the surface of many types of tissues, including the airways, kidneys, and colon. These channels play a crucial role in regulating sodium and fluid balance in the body by allowing the passive movement of sodium ions (Na+) from the lumen or outside of the cell to the inside of the cell, following their electrochemical gradient.

ENaC is composed of three subunits, alpha, beta, and gamma, which are encoded by different genes. The channel is normally closed and opens in response to various stimuli, such as hormones, neurotransmitters, or changes in osmolarity. Once open, the channel allows sodium ions to flow through, creating a positive charge that can attract chloride ions (Cl-) and water molecules, leading to fluid absorption.

In the kidneys, ENaC plays an essential role in regulating sodium reabsorption in the distal nephron, which helps maintain blood pressure and volume. In the airways, ENaC is involved in controlling the hydration of the airway surface liquid, which is necessary for normal mucociliary clearance. Dysregulation of ENaC has been implicated in several diseases, including hypertension, cystic fibrosis, and chronic obstructive pulmonary disease (COPD).

Ion transport refers to the active or passive movement of ions, such as sodium (Na+), potassium (K+), chloride (Cl-), and calcium (Ca2+) ions, across cell membranes. This process is essential for various physiological functions, including nerve impulse transmission, muscle contraction, and maintenance of resting membrane potential.

Ion transport can occur through several mechanisms, including:

1. Diffusion: the passive movement of ions down their concentration gradient, from an area of high concentration to an area of low concentration.
2. Facilitated diffusion: the passive movement of ions through specialized channels or transporters in the cell membrane.
3. Active transport: the energy-dependent movement of ions against their concentration gradient, requiring the use of ATP. This process is often mediated by ion pumps, such as the sodium-potassium pump (Na+/K+-ATPase).
4. Co-transport or symport: the coupled transport of two or more different ions or molecules in the same direction, often driven by an electrochemical gradient.
5. Counter-transport or antiport: the coupled transport of two or more different ions or molecules in opposite directions, also often driven by an electrochemical gradient.

Abnormalities in ion transport can lead to various medical conditions, such as cystic fibrosis (which involves defective chloride channel function), hypertension (which may be related to altered sodium transport), and certain forms of heart disease (which can result from abnormal calcium handling).

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

Calcium channels, N-type ( Cav2.2) are voltage-gated calcium channels found in excitable cells such as neurons and cardiac myocytes. They play a crucial role in regulating various cellular functions, including neurotransmitter release, gene expression, and cell excitability.

N-type calcium channels are composed of five subunits: an alpha1 (Cav2.2) subunit that forms the ion-conducting pore, and four auxiliary subunits (alpha2delta, beta, and gamma) that modulate channel function and stability. The alpha1 subunit contains the voltage sensor and the selectivity filter for calcium ions.

N-type calcium channels are activated by depolarization of the cell membrane and mediate a rapid influx of calcium ions into the cytoplasm. This calcium influx triggers neurotransmitter release from presynaptic terminals, regulates gene expression in the nucleus, and contributes to the electrical excitability of neurons.

N-type calcium channels are also targets for various drugs and toxins that modulate their activity. For example, the peptide toxin from cone snail venom, known as ω-conotoxin MVIIA (Ziconotide), specifically binds to N-type calcium channels and inhibits their activity, making it a potent analgesic for treating chronic pain.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

Barium is a naturally occurring, silvery-white metallic chemical element with the symbol Ba and atomic number 56. In medical terms, barium is commonly used as a contrast agent in radiology, particularly in X-ray examinations such as an upper GI series or barium enema. The barium sulfate powder is mixed with water to create a liquid or thick paste that is swallowed or inserted through the rectum. This provides a white coating on the inside lining of the digestive tract, allowing it to be seen more clearly on X-ray images and helping doctors diagnose various conditions such as ulcers, tumors, or inflammation.

It's important to note that barium is not absorbed by the body and does not cause any harm when used in medical imaging procedures. However, if it is accidentally inhaled or aspirated into the lungs during administration, it can cause chemical pneumonitis, a potentially serious condition. Therefore, it should only be administered under the supervision of trained medical professionals.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

T-type calcium channels are a type of voltage-gated calcium channel that play a role in the regulation of excitable cells, such as neurons and cardiac myocytes. These channels are characterized by their low voltage activation threshold and rapid activation and inactivation kinetics. They are involved in various physiological processes, including neuronal excitability, gene expression, hormone secretion, and heart rhythm. Abnormal functioning of T-type calcium channels has been implicated in several diseases, such as epilepsy, chronic pain, and cardiac arrhythmias.

Gadolinium is a rare earth metal that is used as a contrast agent in medical imaging techniques such as Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA). It works by shortening the relaxation time of protons in tissues, which enhances the visibility of internal body structures on the images. Gadolinium-based contrast agents are injected into the patient's bloodstream during the imaging procedure.

It is important to note that in some individuals, gadolinium-based contrast agents can cause a condition called nephrogenic systemic fibrosis (NSF), which is a rare but serious disorder that affects people with severe kidney disease. NSF causes thickening and hardening of the skin, joints, eyes, and internal organs. Therefore, it is essential to evaluate a patient's renal function before administering gadolinium-based contrast agents.

Large-conductance calcium-activated potassium channels (BK channels) are a type of ion channel found in the membranes of many types of cells, including excitable cells such as neurons and muscle cells. These channels are characterized by their large conductance to potassium ions (K+), which allows them to significantly impact the electrical excitability of cells.

BK channels are activated by both voltage and intracellular calcium ions (Ca2+). They are therefore also known as Ca2+-activated K+ (KCa) channels. When the membrane potential becomes more positive (depolarized), and/or when intracellular Ca2+ levels rise, BK channels open, allowing K+ to flow out of the cell. This efflux of K+ tends to hyperpolarize the membrane potential, making it more difficult for the cell to generate further action potentials or contractile responses.

BK channels play important roles in regulating a variety of physiological processes, including neuronal excitability, neurotransmitter release, vascular tone, and cardiac electrical activity. Dysfunction of BK channels has been implicated in several diseases, such as hypertension, epilepsy, and chronic pain.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are a type of ion channel found in the membranes of excitable cells, such as neurons and cardiac myocytes. These channels are unique because they open in response to membrane hyperpolarization, meaning that they allow the flow of ions into the cell when the voltage becomes more negative.

HCN channels are permeable to both sodium (Na+) and potassium (K+) ions, but they have a stronger preference for Na+ ions. When open, HCN channels conduct a current known as the "funny" or "Ih" current, which plays important roles in regulating the electrical excitability of cells.

HCN channels are also modulated by cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Binding of these molecules to the intracellular domain of the channel can increase its open probability, leading to an enhancement of the funny current.

Dysfunction of HCN channels has been implicated in a variety of neurological and cardiac disorders, including epilepsy, sleep disorders, and heart rhythm abnormalities.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

"Xenopus laevis" is not a medical term itself, but it refers to a specific species of African clawed frog that is often used in scientific research, including biomedical and developmental studies. Therefore, its relevance to medicine comes from its role as a model organism in laboratories.

In a broader sense, Xenopus laevis has contributed significantly to various medical discoveries, such as the understanding of embryonic development, cell cycle regulation, and genetic research. For instance, the Nobel Prize in Physiology or Medicine was awarded in 1963 to John R. B. Gurdon and Sir Michael J. Bishop for their discoveries concerning the genetic mechanisms of organism development using Xenopus laevis as a model system.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Calcium channel agonists are substances that increase the activity or function of calcium channels. Calcium channels are specialized proteins in cell membranes that regulate the flow of calcium ions into and out of cells. They play a crucial role in various physiological processes, including muscle contraction, hormone secretion, and nerve impulse transmission.

Calcium channel agonists can enhance the opening of these channels, leading to an increased influx of calcium ions into the cells. This can result in various pharmacological effects, depending on the type of cell and tissue involved. For example, calcium channel agonists may be used to treat conditions such as hypotension (low blood pressure) or heart block by increasing cardiac contractility and heart rate. However, these agents should be used with caution due to their potential to cause adverse effects, including increased heart rate, hypertension, and arrhythmias.

Examples of calcium channel agonists include drugs such as Bay K 8644, FPL 64176, and A23187. It's important to note that some substances can act as both calcium channel agonists and antagonists, depending on the dose, concentration, or duration of exposure.

Magnesium is an essential mineral that plays a crucial role in various biological processes in the human body. It is the fourth most abundant cation in the body and is involved in over 300 enzymatic reactions, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium also contributes to the structural development of bones and teeth.

In medical terms, magnesium deficiency can lead to several health issues, such as muscle cramps, weakness, heart arrhythmias, and seizures. On the other hand, excessive magnesium levels can cause symptoms like diarrhea, nausea, and muscle weakness. Magnesium supplements or magnesium-rich foods are often recommended to maintain optimal magnesium levels in the body.

Some common dietary sources of magnesium include leafy green vegetables, nuts, seeds, legumes, whole grains, and dairy products. Magnesium is also available in various forms as a dietary supplement, including magnesium oxide, magnesium citrate, magnesium chloride, and magnesium glycinate.

Ether-à-go-go (EAG) potassium channels are a type of voltage-gated potassium channel that are widely expressed in the heart, brain, and other tissues. They are named after the ethereal dance movements observed in fruit flies with mutations in these channels.

EAG potassium channels play important roles in regulating electrical excitability and signaling in excitable cells. In the heart, they help to control the duration of the action potential and the refractory period, which is critical for maintaining normal heart rhythm. In the brain, they are involved in regulating neuronal excitability and neurotransmitter release.

Mutations in EAG potassium channels have been associated with various human diseases, including cardiac arrhythmias, epilepsy, and bipolar disorder. The medical definition of "Ether-A-Go-Go Potassium Channels" refers to the genetic components that make up these channels and their role in physiological processes and disease states.

The Kv1.2 potassium channel is a type of voltage-gated potassium channel that is widely expressed in the nervous system and other tissues. It is composed of four pore-forming α subunits, each of which contains six transmembrane domains and a voltage-sensing domain. These channels play important roles in regulating neuronal excitability, repolarization of action potentials, and controlling neurotransmitter release.

Kv1.2 channels are activated by membrane depolarization and mediate the rapid efflux of potassium ions from cells, which helps to restore the resting membrane potential. They can also be modulated by various intracellular signaling pathways and pharmacological agents, making them targets for therapeutic intervention in a variety of neurological disorders.

Mutations in the KCNA2 gene, which encodes the Kv1.2 channel, have been associated with several human diseases, including episodic ataxia type 1, familial hemiplegic migraine, and spinocerebellar ataxia type 13. These mutations can alter channel function and lead to abnormal neuronal excitability, which may contribute to the symptoms of these disorders.

"Xenopus" is not a medical term, but it is a genus of highly invasive aquatic frogs native to sub-Saharan Africa. They are often used in scientific research, particularly in developmental biology and genetics. The most commonly studied species is Xenopus laevis, also known as the African clawed frog.

In a medical context, Xenopus might be mentioned when discussing their use in research or as a model organism to study various biological processes or diseases.

The Kv1.3 potassium channel is a type of voltage-gated potassium channel that is widely expressed in various tissues, including immune cells such as T lymphocytes. It plays a crucial role in regulating the electrical activity of cells and controlling the flow of potassium ions across the cell membrane.

Kv1.3 channels are composed of four pore-forming alpha subunits, each containing six transmembrane domains. These channels open and close in response to changes in the membrane potential, allowing potassium ions to flow out of the cell when the channel is open. This movement of ions helps to restore the resting membrane potential and regulate the excitability of the cell.

In T lymphocytes, Kv1.3 channels are involved in the regulation of calcium signaling and activation of immune responses. They play a critical role in maintaining the membrane potential and controlling the release of calcium from intracellular stores, which is necessary for T-cell activation and proliferation. Inhibition or blockade of Kv1.3 channels has been shown to suppress T-cell activation and could have potential therapeutic implications in the treatment of autoimmune diseases and transplant rejection.

Kv1.1 potassium channel, also known as KCNA1, is a type of voltage-gated potassium channel that plays a crucial role in the regulation of electrical excitability in neurons and other excitable cells. It is encoded by the KCNA1 gene located on chromosome 12p13.

The Kv1.1 channel is composed of four α-subunits, each containing six transmembrane domains with a pore-forming region between the fifth and sixth domains. These channels are responsible for the rapid repolarization of action potentials in neurons, which helps to control the frequency and pattern of neural activity.

Mutations in the KCNA1 gene have been associated with various neurological disorders, including episodic ataxia type 1 (EA1) and familial hemiplegic migraine (FHM). EA1 is characterized by brief episodes of cerebellar ataxia, myokymia, and neuromyotonia, while FHM is a severe form of migraine with aura that can cause temporary paralysis on one side of the body.

Overall, Kv1.1 potassium channels play an essential role in maintaining normal neural excitability and are critical for proper neurological function.

Cation transport proteins are a type of membrane protein that facilitate the movement of cations (positively charged ions) across biological membranes. These proteins play a crucial role in maintaining ion balance and electrical excitability within cells, as well as in various physiological processes such as nutrient uptake, waste elimination, and signal transduction.

There are several types of cation transport proteins, including:

1. Ion channels: These are specialized protein structures that form a pore or channel through the membrane, allowing ions to pass through rapidly and selectively. They can be either voltage-gated or ligand-gated, meaning they open in response to changes in electrical potential or binding of specific molecules, respectively.

2. Ion pumps: These are active transport proteins that use energy from ATP hydrolysis to move ions against their electrochemical gradient, effectively pumping them from one side of the membrane to the other. Examples include the sodium-potassium pump (Na+/K+-ATPase) and calcium pumps (Ca2+ ATPase).

3. Ion exchangers: These are antiporter proteins that facilitate the exchange of one ion for another across the membrane, maintaining electroneutrality. For example, the sodium-proton exchanger (NHE) moves a proton into the cell in exchange for a sodium ion being moved out.

4. Symporters: These are cotransporter proteins that move two or more ions together in the same direction, often coupled with the transport of a solute molecule. An example is the sodium-glucose cotransporter (SGLT), which facilitates glucose uptake into cells by coupling its movement with that of sodium ions.

Collectively, cation transport proteins help maintain ion homeostasis and contribute to various cellular functions, including electrical signaling, enzyme regulation, and metabolic processes. Dysfunction in these proteins can lead to a range of diseases, such as neurological disorders, cardiovascular disease, and kidney dysfunction.

Calcium signaling is the process by which cells regulate various functions through changes in intracellular calcium ion concentrations. Calcium ions (Ca^2+^) are crucial second messengers that play a critical role in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, and programmed cell death (apoptosis).

Intracellular calcium levels are tightly regulated by a complex network of channels, pumps, and exchangers located on the plasma membrane and intracellular organelles such as the endoplasmic reticulum (ER) and mitochondria. These proteins control the influx, efflux, and storage of calcium ions within the cell.

Calcium signaling is initiated when an external signal, such as a hormone or neurotransmitter, binds to a specific receptor on the plasma membrane. This interaction triggers the opening of ion channels, allowing extracellular Ca^2+^ to flow into the cytoplasm. In some cases, this influx of calcium ions is sufficient to activate downstream targets directly. However, in most instances, the increase in intracellular Ca^2+^ serves as a trigger for the release of additional calcium from internal stores, such as the ER.

The release of calcium from the ER is mediated by ryanodine receptors (RyRs) and inositol trisphosphate receptors (IP3Rs), which are activated by specific second messengers generated in response to the initial external signal. The activation of these channels leads to a rapid increase in cytoplasmic Ca^2+^, creating a transient intracellular calcium signal known as a "calcium spark" or "calcium puff."

These localized increases in calcium concentration can then propagate throughout the cell as waves of elevated calcium, allowing for the spatial and temporal coordination of various cellular responses. The duration and amplitude of these calcium signals are finely tuned by the interplay between calcium-binding proteins, pumps, and exchangers, ensuring that appropriate responses are elicited in a controlled manner.

Dysregulation of intracellular calcium signaling has been implicated in numerous pathological conditions, including neurodegenerative diseases, cardiovascular disorders, and cancer. Therefore, understanding the molecular mechanisms governing calcium homeostasis and signaling is crucial for the development of novel therapeutic strategies targeting these diseases.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

The Kv1.5 potassium channel, also known as KCNA5, is a type of voltage-gated potassium channel that is widely expressed in various tissues, including the heart and blood vessels. It plays a crucial role in regulating electrical excitability and maintaining physiological functions in these tissues.

In the heart, Kv1.5 channels are primarily located in the atria and contribute to the repolarization phase of the cardiac action potential. They help establish the rapid delayed rectifier current (IKr), which is essential for normal atrial electrical activity and maintaining proper heart rhythm. Mutations or dysfunctions in Kv1.5 channels can lead to various cardiac arrhythmias, such as atrial fibrillation.

In blood vessels, Kv1.5 channels are involved in the regulation of vascular tone and blood pressure. They contribute to the hyperpolarization of vascular smooth muscle cells, which leads to vasodilation and decreased peripheral resistance. Dysregulation of Kv1.5 channels has been implicated in several cardiovascular diseases, including hypertension and atherosclerosis.

Overall, Kv1.5 potassium channels are critical for maintaining proper electrical activity in the heart and regulating vascular tone, making them an important target for therapeutic interventions in various cardiovascular disorders.

Degenerin sodium channels, also known as epithelial sodium channels (ENaC), are a type of ion channel found in the membranes of certain cells. They are responsible for the transport of sodium ions (Na+) across the cell membrane and play a crucial role in regulating salt and water balance in the body.

The name "degenerin" comes from their discovery in degenerating nerve cells, where they were found to be activated by mechanical stress or compression. However, it is now known that these channels are widely expressed in various tissues, including the lungs, kidneys, colon, and taste receptor cells.

Degenerin sodium channels are composed of three subunits (α, β, and γ), which form a complex that spans the cell membrane. These channels are selectively permeable to sodium ions and allow them to flow into the cell when the channel is open. The opening and closing of the channel are regulated by various factors, including proteins, lipids, and chemical signals.

In the kidneys, degenerin sodium channels play a critical role in reabsorbing sodium from the urine back into the bloodstream. In the lungs, they help to regulate the movement of salt and water across the airway surface, which is important for maintaining proper lung function. In the colon, these channels are involved in the absorption of sodium and water from the gut lumen.

Abnormalities in degenerin sodium channels have been linked to various diseases, including hypertension, cystic fibrosis, and certain types of cancer. For example, mutations in the genes encoding these channels can lead to an overactive channel, resulting in too much sodium being reabsorbed in the kidneys and contributing to high blood pressure. Similarly, reduced activity of degenerin sodium channels has been implicated in the development of cystic fibrosis, a genetic disorder that affects the lungs and digestive system.

Cell membrane permeability refers to the ability of various substances, such as molecules and ions, to pass through the cell membrane. The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds all cells, controlling what enters and leaves the cell. Its primary function is to protect the cell's internal environment and maintain homeostasis.

The permeability of the cell membrane depends on its structure, which consists of a phospholipid bilayer interspersed with proteins. The hydrophilic (water-loving) heads of the phospholipids face outward, while the hydrophobic (water-fearing) tails face inward, creating a barrier that is generally impermeable to large, polar, or charged molecules.

However, specific proteins within the membrane, called channels and transporters, allow certain substances to cross the membrane. Channels are protein structures that span the membrane and provide a pore for ions or small uncharged molecules to pass through. Transporters, on the other hand, are proteins that bind to specific molecules and facilitate their movement across the membrane, often using energy in the form of ATP.

The permeability of the cell membrane can be influenced by various factors, such as temperature, pH, and the presence of certain chemicals or drugs. Changes in permeability can have significant consequences for the cell's function and survival, as they can disrupt ion balances, nutrient uptake, waste removal, and signal transduction.

Amiloride is a medication that belongs to a class of drugs called potassium-sparing diuretics. It works by preventing the reabsorption of salt and water in the kidneys, which helps to increase urine output and decrease fluid buildup in the body. At the same time, amiloride also helps to preserve the level of potassium in the body, which is why it is known as a potassium-sparing diuretic.

Amiloride is commonly used to treat high blood pressure, heart failure, and edema (fluid buildup) in the body. It is available in tablet form and is typically taken once or twice a day, with or without food. Common side effects of amiloride include headache, dizziness, and stomach upset.

It's important to note that amiloride can interact with other medications, including some over-the-counter products, so it's essential to inform your healthcare provider of all the medications you are taking before starting amiloride therapy. Additionally, regular monitoring of blood pressure, kidney function, and electrolyte levels is necessary while taking this medication.

Lanthanum is not a medical term itself, but it is a chemical element with the symbol "La" and atomic number 57. It is a soft, ductile, silvery-white metal that belongs to the lanthanide series in the periodic table.

However, in medical contexts, lanthanum may be mentioned as a component of certain medications or medical devices. For example, lanthanum carbonate (trade name Fosrenol) is a medication used to treat hyperphosphatemia (elevated levels of phosphate in the blood) in patients with chronic kidney disease. Lanthanum carbonate works by binding to phosphate in the gastrointestinal tract, preventing its absorption into the bloodstream.

It is important to note that lanthanum compounds are not biologically active and do not have any specific medical effects on their own. Any medical uses of lanthanum are related to its physical or chemical properties, rather than its biological activity.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Tetraethylammonium (TEA) is not typically defined in the context of medical terminology, but rather it is a chemical compound with the formula (C2H5)4N+. It is used in research and development, particularly in the field of electrophysiology where it is used as a blocking agent for certain types of ion channels.

Medically, TEA may be mentioned in the context of its potential toxicity or adverse effects on the human body. Exposure to TEA can cause symptoms such as nausea, vomiting, diarrhea, abdominal pain, headache, dizziness, and confusion. Severe exposure can lead to more serious complications, including seizures, respiratory failure, and cardiac arrest.

Therefore, while Tetraethylammonium is not a medical term per se, it is important for healthcare professionals to be aware of its potential health hazards and take appropriate precautions when handling or working with this compound.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

KCNQ potassium channels, also known as Kv7 channels, are a type of voltage-gated potassium channel that play important roles in regulating electrical excitability in various tissues, including the heart and nervous system. These channels are composed of several subunits, typically formed by combinations of KCNQ1 to KCNQ5 proteins, which form a pore through which potassium ions can flow in response to changes in membrane voltage.

KCNQ channels are characterized by their slow activation and deactivation kinetics, which contribute to their role in setting the resting membrane potential and modulating the frequency of action potentials in neurons. In the heart, KCNQ channels help to regulate the duration of the cardiac action potential and are therefore important for maintaining normal heart rhythm.

Mutations in KCNQ channel genes have been associated with a variety of inherited disorders, including long QT syndrome, a condition characterized by abnormalities in the electrical repolarization of the heart that can lead to life-threatening arrhythmias. Other diseases associated with KCNQ channel dysfunction include epilepsy, migraine, and various forms of hearing loss.

Cesium is a chemical element with the symbol "Cs" and atomic number 55. It is a soft, silvery-golden alkali metal that is highly reactive. Cesium is never found in its free state in nature due to its high reactivity. Instead, it is found in minerals such as pollucite.

In the medical field, cesium-137 is a radioactive isotope of cesium that has been used in certain medical treatments and diagnostic procedures. For example, it has been used in the treatment of cancer, particularly in cases where other forms of radiation therapy have not been effective. It can also be used as a source of radiation in brachytherapy, a type of cancer treatment that involves placing radioactive material directly into or near tumors.

However, exposure to high levels of cesium-137 can be harmful and may increase the risk of cancer and other health problems. Therefore, its use in medical treatments is closely regulated and monitored to ensure safety.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Shaker-related Kv1.5 potassium channels, also known as "Shab potassium channels," are a type of voltage-gated potassium channel that play a crucial role in regulating the electrical activity of cells, particularly in the heart and nervous system. These channels are named after the Shaker gene in Drosophila melanogaster (fruit flies) where they were first discovered and characterized.

The Kv1.5 channel is composed of four pore-forming α-subunits that assemble to form a tetrameric complex. Each α-subunit contains six transmembrane domains, with the voltage-sensing domain located in the fourth transmembrane segment and the potassium selectivity filter located in the pore region between the fifth and sixth transmembrane segments.

Kv1.5 channels are activated by membrane depolarization and contribute to the repolarization phase of the action potential in cardiac myocytes, helping to maintain the normal rhythm of the heart. In addition, Kv1.5 channels play a role in regulating neuronal excitability and neurotransmitter release in the nervous system.

Mutations in the KCNA5 gene, which encodes the Kv1.5 channel, have been associated with various cardiac arrhythmias, including atrial fibrillation and Brugada syndrome. Pharmacological blockade of Kv1.5 channels has also been shown to have potential therapeutic benefits in the treatment of atrial fibrillation and other cardiovascular disorders.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

The KCNQ1 potassium channel, also known as the Kv7.1 channel, is a voltage-gated potassium ion channel that plays a crucial role in the regulation of electrical excitability in cardiac myocytes and inner ear epithelial cells. In the heart, it helps to control the duration and frequency of action potentials, thereby contributing to the maintenance of normal cardiac rhythm. Mutations in the KCNQ1 gene can lead to various cardiac disorders, such as long QT syndrome type 1 and familial atrial fibrillation. In the inner ear, it helps regulate potassium homeostasis and is essential for hearing and balance functions. Dysfunction of this channel has been linked to deafness and balance disorders.

Organic cation transport proteins (OCTs) are a group of membrane transporters that facilitate the movement of organic cations across biological membranes. These transporters play an essential role in the absorption, distribution, and elimination of various endogenous and exogenous substances, including drugs and toxins.

There are four main types of OCTs, namely OCT1, OCT2, OCT3, and OCTN1 (also known as novel organic cation transporter 1 or OCT6). These proteins belong to the solute carrier (SLC) family, specifically SLC22A.

OCTs have a broad substrate specificity and can transport various organic cations, such as neurotransmitters (e.g., serotonin, dopamine, histamine), endogenous compounds (e.g., creatinine, choline), and drugs (e.g., metformin, quinidine, morphine). The transport process is typically sodium-independent and can occur in both directions, depending on the concentration gradient of the substrate.

OCTs are widely expressed in various tissues, including the liver, kidney, intestine, brain, heart, and placenta. Their expression patterns and functions vary among different OCT types, contributing to their diverse roles in physiology and pharmacology. Dysfunction of OCTs has been implicated in several diseases, such as drug toxicity, neurodegenerative disorders, and cancer.

In summary, organic cation transport proteins are membrane transporters that facilitate the movement of organic cations across biological membranes, playing crucial roles in the absorption, distribution, and elimination of various substances, including drugs and toxins.

Small-conductance calcium-activated potassium channels (SK channels) are a type of ion channel found in the membranes of excitable cells, such as neurons and muscle cells. They are called "calcium-activated" because their opening is triggered by an increase in intracellular calcium ions (Ca2+), and "potassium channels" because they are selectively permeable to potassium ions (K+).

SK channels have a small conductance, meaning that they allow only a relatively small number of ions to pass through them at any given time. This makes them less influential in shaping the electrical properties of cells compared to other types of potassium channels with larger conductances.

SK channels play important roles in regulating neuronal excitability and neurotransmitter release, as well as controlling the contraction and relaxation of smooth muscle cells. They are activated by calcium ions that enter the cell through voltage-gated calcium channels or other types of Ca2+ channels, and their opening leads to an efflux of K+ ions from the cell. This efflux of positive charges tends to hyperpolarize the membrane potential, making it more difficult for the cell to generate action potentials and release neurotransmitters.

There are three subtypes of SK channels, designated as SK1, SK2, and SK3, which differ in their biophysical properties and sensitivity to pharmacological agents. These channels have been implicated in a variety of physiological processes, including learning and memory, pain perception, blood pressure regulation, and the pathogenesis of certain neurological disorders.

HEK293 cells, also known as human embryonic kidney 293 cells, are a line of cells used in scientific research. They were originally derived from human embryonic kidney cells and have been adapted to grow in a lab setting. HEK293 cells are widely used in molecular biology and biochemistry because they can be easily transfected (a process by which DNA is introduced into cells) and highly express foreign genes. As a result, they are often used to produce proteins for structural and functional studies. It's important to note that while HEK293 cells are derived from human tissue, they have been grown in the lab for many generations and do not retain the characteristics of the original embryonic kidney cells.

Thapsigargin is not a medical term per se, but it is a chemical compound that has been studied in the field of medicine and biology. Thapsigargin is a substance that is derived from the plant Thapsia garganica, also known as the "deadly carrot." It is a powerful inhibitor of the sarcoendoplasmic reticulum calcium ATPase (SERCA) pump, which is responsible for maintaining calcium homeostasis within cells.

Thapsigargin has been studied for its potential use in cancer therapy due to its ability to induce cell death in certain types of cancer cells. However, its use as a therapeutic agent is still being investigated and is not yet approved for medical use. It should be noted that thapsigargin can also have toxic effects on normal cells, so its therapeutic use must be carefully studied and optimized to minimize harm to healthy tissues.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a net electric charge. Cations are positively charged ions, which have lost electrons, while anions are negatively charged ions, which have gained electrons. Ions can play a significant role in various physiological processes within the human body, including enzyme function, nerve impulse transmission, and maintenance of acid-base balance. They also contribute to the formation of salts and buffer systems that help regulate fluid composition and pH levels in different bodily fluids.

Chlorides are simple inorganic ions consisting of a single chlorine atom bonded to a single charged hydrogen ion (H+). Chloride is the most abundant anion (negatively charged ion) in the extracellular fluid in the human body. The normal range for chloride concentration in the blood is typically between 96-106 milliequivalents per liter (mEq/L).

Chlorides play a crucial role in maintaining electrical neutrality, acid-base balance, and osmotic pressure in the body. They are also essential for various physiological processes such as nerve impulse transmission, maintenance of membrane potentials, and digestion (as hydrochloric acid in the stomach).

Chloride levels can be affected by several factors, including diet, hydration status, kidney function, and certain medical conditions. Increased or decreased chloride levels can indicate various disorders, such as dehydration, kidney disease, Addison's disease, or diabetes insipidus. Therefore, monitoring chloride levels is essential for assessing a person's overall health and diagnosing potential medical issues.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

Purinergic P2X receptors are a type of ligand-gated ion channel that are activated by the binding of extracellular ATP (adenosine triphosphate) and other purinergic agonists. These receptors play important roles in various physiological processes, including neurotransmission, pain perception, and immune response.

P2X receptors are composed of three subunits that form a functional ion channel. There are seven different subunits (P2X1-7) that can assemble to form homo- or heterotrimeric receptor complexes with distinct functional properties.

Upon activation by ATP, P2X receptors undergo conformational changes that allow for the flow of cations, such as calcium (Ca^2+^), sodium (Na^+^), and potassium (K^+^) ions, across the cell membrane. This ion flux can lead to a variety of downstream signaling events, including the activation of second messenger systems and changes in gene expression.

Purinergic P2X receptors have been implicated in a number of pathological conditions, including chronic pain, inflammation, and neurodegenerative diseases. As such, they are an active area of research for the development of novel therapeutic strategies.

Organic Cation Transporter 1 (OCT1) is a protein that belongs to the solute carrier family 22 (SLC22A). It is primarily expressed in the liver and plays an essential role in the uptake and elimination of various organic cations, including many drugs, from the systemic circulation into hepatocytes. OCT1 also transports some endogenous substances such as neurotransmitters and hormones. Mutations or variants in the OCT1 gene can affect drug response and disposition, making it an important factor to consider in personalized medicine.

The Kv1.4 potassium channel, also known as the KCNA4 channel, is a type of voltage-gated potassium channel that is widely expressed in various tissues, including the heart, brain, and skeletal muscle. It plays a crucial role in regulating electrical excitability and membrane potential in these cells.

The Kv1.4 channel is composed of four α-subunits, each containing six transmembrane domains with a pore-forming region between the fifth and sixth domains. The channel opens in response to depolarization of the membrane potential, allowing potassium ions to flow out of the cell, which helps to repolarize the membrane and terminate the action potential.

In the heart, Kv1.4 channels are expressed in the pacemaker cells of the sinoatrial node and help to regulate the heart rate. In the brain, they are involved in regulating neuronal excitability and neurotransmitter release. In skeletal muscle, Kv1.4 channels contribute to the regulation of membrane potential during muscle contraction and relaxation.

Mutations in the KCNA4 gene, which encodes the Kv1.4 channel, have been associated with various inherited arrhythmia syndromes, including familial atrial fibrillation and progressive conduction disease.

Boron compounds refer to chemical substances that contain the element boron (symbol: B) combined with one or more other elements. Boron is a naturally occurring, non-metallic element found in various minerals and ores. It is relatively rare, making up only about 0.001% of the Earth's crust by weight.

Boron compounds can take many forms, including salts, acids, and complex molecules. Some common boron compounds include:

* Boric acid (H3BO3) - a weak acid used as an antiseptic, preservative, and insecticide
* Sodium borate (Na2B4O7·10H2O) - also known as borax, a mineral used in detergents, cosmetics, and enamel glazes
* Boron carbide (B4C) - an extremely hard material used in abrasives, ceramics, and nuclear reactors
* Boron nitride (BN) - a compound with properties similar to graphite, used as a lubricant and heat shield

Boron compounds have a variety of uses in medicine, including as antiseptics, anti-inflammatory agents, and drugs for the treatment of cancer. For example, boron neutron capture therapy (BNCT) is an experimental form of radiation therapy that uses boron-containing compounds to selectively target and destroy cancer cells.

It's important to note that some boron compounds can be toxic or harmful if ingested, inhaled, or otherwise exposed to the body in large quantities. Therefore, they should be handled with care and used only under the guidance of a trained medical professional.

An action potential is a brief electrical signal that travels along the membrane of a nerve cell (neuron) or muscle cell. It is initiated by a rapid, localized change in the permeability of the cell membrane to specific ions, such as sodium and potassium, resulting in a rapid influx of sodium ions and a subsequent efflux of potassium ions. This ion movement causes a brief reversal of the electrical potential across the membrane, which is known as depolarization. The action potential then propagates along the cell membrane as a wave, allowing the electrical signal to be transmitted over long distances within the body. Action potentials play a crucial role in the communication and functioning of the nervous system and muscle tissue.

The Ryanodine Receptor (RyR) is a calcium release channel located on the sarcoplasmic reticulum (SR), a type of endoplasmic reticulum found in muscle cells. It plays a crucial role in excitation-contraction coupling, which is the process by which electrical signals are converted into mechanical responses in muscle fibers.

In more detail, when an action potential reaches the muscle fiber's surface membrane, it triggers the opening of voltage-gated L-type calcium channels (Dihydropyridine Receptors or DHPRs) in the sarcolemma (the cell membrane of muscle fibers). This influx of calcium ions into the cytoplasm causes a conformational change in the RyR, leading to its own opening and the release of stored calcium from the SR into the cytoplasm. The increased cytoplasmic calcium concentration then initiates muscle contraction through interaction with contractile proteins like actin and myosin.

There are three isoforms of RyR: RyR1, RyR2, and RyR3. RyR1 is primarily found in skeletal muscle, while RyR2 is predominantly expressed in cardiac muscle. Both RyR1 and RyR2 are large homotetrameric proteins with a molecular weight of approximately 2.2 million Daltons. They contain multiple domains including an ion channel pore, regulatory domains, and a foot structure that interacts with DHPRs. RyR3 is more widely distributed, being found in various tissues such as the brain, smooth muscle, and some types of neurons.

Dysfunction of these channels has been implicated in several diseases including malignant hyperthermia, central core disease, catecholaminergic polymorphic ventricular tachycardia (CPVT), and certain forms of heart failure.

Diacylglycerols (also known as diglycerides) are a type of glyceride, which is a compound that consists of glycerol and one or more fatty acids. Diacylglycerols contain two fatty acid chains bonded to a glycerol molecule through ester linkages. They are important intermediates in the metabolism of lipids and can be found in many types of food, including vegetable oils and dairy products. In the body, diacylglycerols can serve as a source of energy and can also play roles in cell signaling processes.

I'm sorry for any confusion, but "Oxocins" is not a recognized term in medical terminology. It seems like it might be a mistake or a typo. If you have more context or information about where this term came from, I may be able to provide a more accurate and helpful response.

Shaw potassium channels, also known as KCNA4 channels, are a type of voltage-gated potassium channel that is encoded by the KCNA4 gene in humans. These channels play a crucial role in regulating the electrical excitability of cells, particularly in the heart and nervous system.

Shaw channels are named after James E. Shaw, who first identified them in 1996. They are composed of four subunits that arrange themselves to form a central pore through which potassium ions can flow. The channels are activated by depolarization of the cell membrane and help to repolarize the membrane during action potentials.

Mutations in the KCNA4 gene have been associated with various cardiac arrhythmias, including familial atrial fibrillation and long QT syndrome type 3. These conditions can cause irregular heart rhythms and may increase the risk of sudden cardiac death. Therefore, understanding the function and regulation of Shaw potassium channels is important for developing therapies to treat these disorders.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Purinergic P2X4 receptors are a type of ionotropic purinergic receptor that are activated by adenosine triphosphate (ATP) and related nucleotides. They belong to the P2X receptor family, which includes seven subtypes (P2X1-7) that form trimeric channels permeable to cations such as calcium, sodium, and potassium.

The P2X4 receptor is widely expressed in various tissues, including the central and peripheral nervous systems, immune cells, and epithelial cells. It plays a role in several physiological processes, including neurotransmission, inflammation, and pain perception. Activation of P2X4 receptors leads to an increase in intracellular calcium concentration and membrane depolarization, which can modulate synaptic transmission and cell excitability.

P2X4 receptors have also been implicated in various pathological conditions, such as neuropathic pain, neuroinflammation, and ischemic injury. They are involved in the release of pro-inflammatory cytokines and chemokines from immune cells, contributing to the development of chronic inflammation and tissue damage.

In summary, purinergic P2X4 receptors are a type of ATP-gated ion channel that play important roles in physiological and pathological processes, including neurotransmission, inflammation, and pain perception.

A lipid bilayer is a thin membrane made up of two layers of lipid molecules, primarily phospholipids. The hydrophilic (water-loving) heads of the lipids face outwards, coming into contact with watery environments on both sides, while the hydrophobic (water-fearing) tails point inward, away from the aqueous surroundings. This unique structure allows lipid bilayers to form a stable barrier that controls the movement of molecules and ions in and out of cells and organelles, thus playing a crucial role in maintaining cellular compartmentalization and homeostasis.

I'm sorry for any confusion, but "Shal Potassium Channels" is not a widely recognized or established medical term in the field of physiology or pharmacology. It seems like there might be a misunderstanding or a typo in the term you're looking for.

If you're referring to " Shaw Potassium Channels," these are a type of voltage-gated potassium channel named after the scientist who first described them, Robert A. Shaw. These channels play crucial roles in various physiological processes, including the regulation of heart rate and excitability of nerve cells.

If you meant to ask about something else or need further clarification, please provide more context or check the spelling, and I'll be happy to help!

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Manganese is not a medical condition, but it's an essential trace element that is vital for human health. Here is the medical definition of Manganese:

Manganese (Mn) is a trace mineral that is present in tiny amounts in the body. It is found mainly in bones, the liver, kidneys, and pancreas. Manganese helps the body form connective tissue, bones, blood clotting factors, and sex hormones. It also plays a role in fat and carbohydrate metabolism, calcium absorption, and blood sugar regulation. Manganese is also necessary for normal brain and nerve function.

The recommended dietary allowance (RDA) for manganese is 2.3 mg per day for adult men and 1.8 mg per day for adult women. Good food sources of manganese include nuts, seeds, legumes, whole grains, green leafy vegetables, and tea.

In some cases, exposure to high levels of manganese can cause neurological symptoms similar to Parkinson's disease, a condition known as manganism. However, this is rare and usually occurs in people who are occupationally exposed to manganese dust or fumes, such as welders.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

In the context of medicine and physiology, permeability refers to the ability of a tissue or membrane to allow the passage of fluids, solutes, or gases. It is often used to describe the property of the capillary walls, which control the exchange of substances between the blood and the surrounding tissues.

The permeability of a membrane can be influenced by various factors, including its molecular structure, charge, and the size of the molecules attempting to pass through it. A more permeable membrane allows for easier passage of substances, while a less permeable membrane restricts the movement of substances.

In some cases, changes in permeability can have significant consequences for health. For example, increased permeability of the blood-brain barrier (a specialized type of capillary that regulates the passage of substances into the brain) has been implicated in a number of neurological conditions, including multiple sclerosis, Alzheimer's disease, and traumatic brain injury.

Nifedipine is an antihypertensive and calcium channel blocker medication. It works by relaxing the muscles of the blood vessels, which helps to lower blood pressure and improve the supply of oxygen and nutrients to the heart. Nifedipine is used to treat high blood pressure (hypertension), angina (chest pain), and certain types of heart rhythm disorders.

In medical terms, nifedipine can be defined as: "A dihydropyridine calcium channel blocker that is used in the treatment of hypertension, angina pectoris, and Raynaud's phenomenon. It works by inhibiting the influx of calcium ions into vascular smooth muscle and cardiac muscle, which results in relaxation of the vascular smooth muscle and decreased workload on the heart."

G protein-coupled inwardly-rectifying potassium channels (GIRK channels) are a type of potassium channel that are activated by G proteins, which are molecules that help transmit signals within cells. These channels are characterized by their ability to allow potassium ions to flow into the cell more easily than they allow potassium ions to flow out of the cell, hence the term "inwardly-rectifying."

GIRK channels play a role in regulating various physiological processes, including neurotransmission, heart rate, and insulin secretion. They are activated by several different G proteins, including those that are activated by certain neurotransmitters and hormones. When these G proteins bind to the channel, they cause it to open, allowing potassium ions to flow into the cell. This can have various effects on the cell, depending on the type of cell and the specific signals being transmitted.

GIRK channels are composed of four subunits, each of which contains a pore through which potassium ions can pass. These subunits can be made up of different types of proteins, and the specific combination of subunits in a channel can affect its properties and regulation. Mutations in genes that encode GIRK channel subunits have been linked to various diseases, including certain forms of epilepsy and cardiac arrhythmias.

A protein subunit refers to a distinct and independently folding polypeptide chain that makes up a larger protein complex. Proteins are often composed of multiple subunits, which can be identical or different, that come together to form the functional unit of the protein. These subunits can interact with each other through non-covalent interactions such as hydrogen bonds, ionic bonds, and van der Waals forces, as well as covalent bonds like disulfide bridges. The arrangement and interaction of these subunits contribute to the overall structure and function of the protein.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Smooth muscle myocytes are specialized cells that make up the contractile portion of non-striated, or smooth, muscles. These muscles are found in various organs and structures throughout the body, including the walls of blood vessels, the digestive system, the respiratory system, and the reproductive system.

Smooth muscle myocytes are smaller than their striated counterparts (skeletal and cardiac muscle cells) and have a single nucleus. They lack the distinctive banding pattern seen in striated muscles and instead have a uniform appearance of actin and myosin filaments. Smooth muscle myocytes are controlled by the autonomic nervous system, which allows them to contract and relax involuntarily.

These cells play an essential role in many physiological processes, such as regulating blood flow, moving food through the digestive tract, and facilitating childbirth. They can also contribute to various pathological conditions, including hypertension, atherosclerosis, and gastrointestinal disorders.

Large-conductance calcium-activated potassium channels, also known as BK channels, are a type of ion channel that are activated by both voltage and the presence of intracellular calcium ions. The alpha subunit is one of the four subunits that make up the functional channel. The alpha subunit contains the central pore of the channel through which potassium ions flow, as well as the binding sites for calcium ions that allow the channel to be activated. These channels play a crucial role in regulating vascular tone, neurotransmitter release and excitability of many types of cells. Mutations in the gene encoding the alpha subunit can lead to various human diseases, such as hypertension, epilepsy, and autism.

Fura-2 is not a medical term per se, but a chemical compound used in scientific research, particularly in the field of physiology and cell biology. Fura-2 is a calcium indicator dye that is commonly used to measure intracellular calcium concentrations in living cells. It works by binding to calcium ions (Ca²+) in the cytoplasm of cells, which causes a change in its fluorescence emission spectrum.

When excited with ultraviolet light at specific wavelengths, Fura-2 exhibits different fluorescence intensities depending on the concentration of calcium ions it has bound to. By measuring these changes in fluorescence intensity, researchers can quantify intracellular calcium levels and study how they change in response to various stimuli or experimental conditions.

While Fura-2 is not a medical term itself, understanding its function and use is essential for researchers working in the fields of physiology, pharmacology, neuroscience, and other biomedical disciplines.

KCNQ2 potassium channel, also known as Kv7.2 channel, is a type of voltage-gated potassium channel that plays a crucial role in regulating the electrical excitability of neurons. The channel is composed of four KCNQ2 subunits and can form heteromeric complexes with KCNQ3 subunits to form the M-current, which helps to set the resting membrane potential and control the firing frequency of action potentials in neurons.

Mutations in the KCNQ2 gene have been associated with a variety of neurological disorders, including benign familial neonatal seizures (BFNS), epileptic encephalopathy, and intellectual disability. These mutations can alter the function or expression of the KCNQ2 channel, leading to abnormal neuronal excitability and seizure activity.

In summary, KCNQ2 potassium channel is a type of voltage-gated potassium channel that helps regulate the electrical excitability of neurons and has been implicated in several neurological disorders when its function is altered due to genetic mutations.

Purinergic P2 receptors are a type of cell surface receptor that bind to purine nucleotides and nucleosides, such as ATP (adenosine triphosphate) and ADP (adenosine diphosphate), and mediate various physiological responses. These receptors are divided into two main families: P2X and P2Y.

P2X receptors are ionotropic receptors, meaning they form ion channels that allow the flow of ions across the cell membrane upon activation. There are seven subtypes of P2X receptors (P2X1-7), each with distinct functional and pharmacological properties.

P2Y receptors, on the other hand, are metabotropic receptors, meaning they activate intracellular signaling pathways through G proteins. There are eight subtypes of P2Y receptors (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and P2Y14), each with different G protein coupling specificities and downstream signaling pathways.

Purinergic P2 receptors are widely expressed in various tissues, including the nervous system, cardiovascular system, respiratory system, gastrointestinal tract, and immune system. They play important roles in regulating physiological functions such as neurotransmission, vasodilation, platelet aggregation, smooth muscle contraction, and inflammation. Dysregulation of purinergic P2 receptors has been implicated in various pathological conditions, including pain, ischemia, hypertension, atherosclerosis, and cancer.

Drug receptors are specific protein molecules found on the surface of cells, to which drugs can bind. These receptors are part of the cell's communication system and are responsible for responding to neurotransmitters, hormones, and other signaling molecules in the body. When a drug binds to its corresponding receptor, it can alter the receptor's function and trigger a cascade of intracellular events that ultimately lead to a biological response.

Drug receptors can be classified into several types based on their function, including:

1. G protein-coupled receptors (GPCRs): These are the largest family of drug receptors and are involved in various physiological processes such as vision, olfaction, neurotransmission, and hormone signaling. They activate intracellular signaling pathways through heterotrimeric G proteins.
2. Ion channel receptors: These receptors form ion channels that allow the flow of ions across the cell membrane when activated. They are involved in rapid signal transduction and can be directly gated by ligands or indirectly through G protein-coupled receptors.
3. Enzyme-linked receptors: These receptors have an intracellular domain that functions as an enzyme, activating intracellular signaling pathways when bound to a ligand. Examples include receptor tyrosine kinases and receptor serine/threonine kinases.
4. Nuclear receptors: These receptors are located in the nucleus and function as transcription factors, regulating gene expression upon binding to their ligands.

Understanding drug receptors is crucial for developing new drugs and predicting their potential therapeutic and adverse effects. By targeting specific receptors, drugs can modulate cellular responses and produce desired pharmacological actions.

Membrane transport modulators refer to a class of molecules that affect the movement of ions, nutrients, and other substances across cell membranes by interacting with membrane transport proteins. These proteins, also known as transporters or carriers, facilitate the passive or active transport of molecules in and out of cells.

Membrane transport modulators can either inhibit or enhance the activity of these transport proteins. They play a crucial role in pharmacology and therapeutics, as they can influence drug absorption, distribution, metabolism, and excretion (ADME). Examples of membrane transport modulators include ion channel blockers, inhibitors of efflux pumps like P-glycoprotein, and enhancers of nutrient uptake transporters.

It is important to note that the term "membrane transport modulator" can encompass a wide range of molecules with varying mechanisms and specificities, so further characterization is often necessary for a more precise understanding of their effects.

Carbachol is a cholinergic agonist, which means it stimulates the parasympathetic nervous system by mimicking the action of acetylcholine, a neurotransmitter that is involved in transmitting signals between nerves and muscles. Carbachol binds to both muscarinic and nicotinic receptors, but its effects are more pronounced on muscarinic receptors.

Carbachol is used in medical treatments to produce miosis (pupil constriction), lower intraocular pressure, and stimulate gastrointestinal motility. It can also be used as a diagnostic tool to test for certain conditions such as Hirschsprung's disease.

Like any medication, carbachol can have side effects, including sweating, salivation, nausea, vomiting, diarrhea, bradycardia (slow heart rate), and bronchoconstriction (narrowing of the airways in the lungs). It should be used with caution and under the supervision of a healthcare professional.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Ruthenium Red is not a medical term itself, but it is a chemical compound that has been used in some medical research and procedures. Ruthenium Red is a dye that is used as a marker in electron microscopy to stain and highlight cellular structures, particularly mitochondria, the energy-producing organelles of cells. It can also be used in experimental treatments for conditions such as heart failure and neurodegenerative diseases.

In summary, Ruthenium Red is a chemical compound with potential medical applications as a research tool and experimental treatment, rather than a standalone medical condition or diagnosis.

Purinergic P2X7 receptors are a type of ligand-gated ion channel that are activated by the binding of extracellular adenosine triphosphate (ATP) to the P2X7 receptor subunit. These receptors play important roles in various physiological and pathophysiological processes, including inflammation, immune response, pain perception, and cell death.

Upon activation of P2X7 receptors, there is an increase in membrane permeability to small cations such as Na+, K+, and Ca2+, which can lead to the depolarization of the cell membrane. Prolonged activation of these receptors can result in the formation of large pores that allow for the passage of larger molecules, including inflammatory mediators and even small proteins. This can ultimately lead to the induction of apoptosis or necrosis in certain cells.

P2X7 receptors are widely expressed in various tissues, including the brain, spinal cord, immune cells, and epithelial cells. In recent years, there has been growing interest in targeting P2X7 receptors for therapeutic purposes, particularly in the context of inflammatory diseases and chronic pain.

Strontium is not a medical term, but it is a chemical element with the symbol Sr and atomic number 38. It is a soft silver-white or yellowish metallic element that is highly reactive chemically. In the medical field, strontium ranelate is a medication used to treat osteoporosis in postmenopausal women. It works by increasing the formation of new bone and decreasing bone resorption (breakdown).

It is important to note that strontium ranelate has been associated with an increased risk of cardiovascular events, such as heart attack and stroke, so it is not recommended for people with a history of these conditions. Additionally, the use of strontium supplements in high doses can be toxic and should be avoided.

Calcium channels, P-type, are a specific type of voltage-gated calcium channel found in excitable cells such as neurons and muscle cells. They are named "P-type" because they were initially identified in Purkinje cells of the cerebellum. These channels play a crucial role in various cellular processes, including neurotransmitter release, muscle contraction, and gene expression.

P-type calcium channels are characterized by their unique biophysical properties, such as slow voltage-dependent activation and inactivation, as well as sensitivity to the drug felodipine. They are composed of several subunits, including the pore-forming α1 subunit, which contains the voltage sensor and the selectivity filter for calcium ions. The α1 subunit is associated with accessory subunits, such as β, γ, and δ, that modulate the channel's properties and trafficking to the cell membrane.

P-type calcium channels are important targets for therapeutic interventions in various diseases, including neurological disorders, cardiovascular diseases, and cancer. For example, drugs that block P-type calcium channels have been used to treat hypertension and angina, while activators of these channels have shown promise in treating neurodegenerative disorders such as Parkinson's disease.

Niflumic acid is a non-steroidal anti-inflammatory drug (NSAID) that is primarily used as a topical agent for the treatment of pain and inflammation associated with various musculoskeletal conditions, such as strains, sprains, and arthritis. It works by inhibiting the activity of cyclooxygenase (COX) enzymes, which are involved in the production of prostaglandins, chemicals that mediate inflammation, pain, and fever.

Niflumic acid is available as a cream or gel for topical application, and it is not typically used for systemic treatment due to its potential gastrointestinal side effects. It may also be used off-label for the treatment of other conditions that involve pain and inflammation. As with any medication, niflumic acid should only be used under the guidance of a healthcare professional, and it is important to follow all dosage instructions carefully to minimize the risk of adverse effects.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

NAV1.5, also known as SCN5A, is a specific type of voltage-gated sodium channel found in the heart muscle cells (cardiomyocytes). These channels play a crucial role in the generation and transmission of electrical signals that coordinate the contraction of the heart.

More specifically, NAV1.5 channels are responsible for the rapid influx of sodium ions into cardiomyocytes during the initial phase of the action potential, which is the electrical excitation of the cell. This rapid influx of sodium ions helps to initiate and propagate the action potential throughout the heart muscle, allowing for coordinated contraction and proper heart function.

Mutations in the SCN5A gene, which encodes the NAV1.5 channel, have been associated with various cardiac arrhythmias, including long QT syndrome, Brugada syndrome, and familial atrial fibrillation, among others. These genetic disorders can lead to abnormal heart rhythms, syncope, and in some cases, sudden cardiac death.

Intermediate-conductance calcium-activated potassium channels (IKCa) are a type of ion channel found in various cell types, including immune cells, endothelial cells, and neurons. These channels are activated by an increase in intracellular calcium ions (Ca2+) and allow the flow of potassium ions (K+) out of the cell.

IKCa channels have a single-channel conductance that is intermediate between small-conductance (SKCa) and large-conductance (BKCa) calcium-activated potassium channels, typically ranging from 20 to 100 picosiemens (pS). They are encoded by the KCNN4 gene in humans.

The activation of IKCa channels plays a crucial role in regulating various cellular processes, such as membrane potential, calcium signaling, and immune response. For example, in activated immune cells, the opening of IKCa channels helps to repolarize the membrane potential and limit further Ca2+ entry into the cell, thereby modulating cytokine production and inflammatory responses. In endothelial cells, IKCa channel activation can regulate vascular tone and blood flow by controlling the diameter of blood vessels.

Capsaicin is defined in medical terms as the active component of chili peppers (genus Capsicum) that produces a burning sensation when it comes into contact with mucous membranes or skin. It is a potent irritant and is used topically as a counterirritant in some creams and patches to relieve pain. Capsaicin works by depleting substance P, a neurotransmitter that relays pain signals to the brain, from nerve endings.

Here is the medical definition of capsaicin from the Merriam-Webster's Medical Dictionary:

caпсаісіn : an alkaloid (C18H27NO3) that is the active principle of red peppers and is used in topical preparations as a counterirritant and analgesic.

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a type of calcium ion channel found in the endoplasmic reticulum (ER) membrane of many cell types. They play a crucial role in intracellular calcium signaling and are activated by the second messenger molecule, inositol 1,4,5-trisphosphate (IP3).

IP3 is produced by enzymatic cleavage of the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) in response to extracellular signals such as hormones and neurotransmitters. When IP3 binds to the IP3R, it triggers a conformational change that opens the channel, allowing calcium ions to flow from the ER into the cytosol. This increase in cytosolic calcium can then activate various cellular processes such as gene expression, protein synthesis, and cell survival or death pathways.

There are three isoforms of IP3Rs (IP3R1, IP3R2, and IP3R3) that differ in their tissue distribution, regulation, and sensitivity to IP3. Dysregulation of IP3R-mediated calcium signaling has been implicated in various pathological conditions, including neurological disorders, cardiovascular diseases, and cancer.

KCNQ3 potassium channel, also known as Kv7.3 or KvLQT3, is a type of voltage-gated potassium channel that plays a crucial role in the regulation of electrical excitability in the brain and other tissues. These channels are composed of four α subunits that form a tetrameric complex, with each subunit containing six transmembrane domains and a pore region.

The KCNQ3 channel is widely expressed in the central nervous system, where it contributes to the regulation of neuronal excitability by mediating the slow component of the delayed rectifier potassium current (IKs). This current helps to set the resting membrane potential and control the firing pattern of action potentials in neurons.

Mutations in the KCNQ3 gene have been associated with a variety of neurological disorders, including benign familial neonatal seizures (BFNS), epileptic encephalopathy, and intellectual disability. These mutations can alter the electrical properties of the channel, leading to changes in neuronal excitability and network activity that underlie these conditions.

Overall, the KCNQ3 potassium channel is an important regulator of neural function and a potential target for therapeutic intervention in neurological disorders associated with altered neuronal excitability.

Gramicidin is not a medical condition but rather an antibiotic substance that is used in medical treatments.

Here's the scientific and pharmacological definition:

Gramicidin is a narrow-spectrum, cationic antimicrobial peptide derived from gram-positive bacteria of the genus Bacillus. It is an ionophore that selectively binds to monovalent cations, forming channels in lipid bilayers and causing disruption of bacterial cell membranes, leading to bacterial lysis and death. Gramicidin D, a mixture of at least four different gramicidins (A, B, C, and D), is commonly used in topical formulations for the treatment of skin and eye infections due to its potent antimicrobial activity against many gram-positive and some gram-negative bacteria. However, it has limited systemic use due to its potential toxicity to mammalian cells.

A smooth muscle within the vascular system refers to the involuntary, innervated muscle that is found in the walls of blood vessels. These muscles are responsible for controlling the diameter of the blood vessels, which in turn regulates blood flow and blood pressure. They are called "smooth" muscles because their individual muscle cells do not have the striations, or cross-striped patterns, that are observed in skeletal and cardiac muscle cells. Smooth muscle in the vascular system is controlled by the autonomic nervous system and by hormones, and can contract or relax slowly over a period of time.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

I'm sorry for any confusion, but "Rubidium" is not a medical term. It is a chemical element with the symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metal that is highly reactive and flammable. It is found in trace amounts in minerals such as leucite and pollucite.

While rubidium itself does not have a direct medical application, its radioisotopes (such as rubidium-82) are used in medical imaging, particularly in positron emission tomography (PET) scans, to study heart function and blood flow. However, the term "Rubidium" itself is not used in a medical context to define a condition or disease.

Glyburide is a medication that falls under the class of drugs known as sulfonylureas. It is primarily used to manage type 2 diabetes by lowering blood sugar levels. Glyburide works by stimulating the release of insulin from the pancreas, thereby increasing the amount of insulin available in the body to help glucose enter cells and decrease the level of glucose in the bloodstream.

The medical definition of Glyburide is:
A second-generation sulfonylurea antidiabetic drug (oral hypoglycemic) used in the management of type 2 diabetes mellitus. It acts by stimulating pancreatic beta cells to release insulin and increases peripheral glucose uptake and utilization, thereby reducing blood glucose levels. Glyburide may also decrease glucose production in the liver.

It is important to note that Glyburide should be used as part of a comprehensive diabetes management plan that includes proper diet, exercise, regular monitoring of blood sugar levels, and other necessary lifestyle modifications. As with any medication, it can have side effects and potential interactions with other drugs, so it should only be taken under the supervision of a healthcare provider.

Scorpion venoms are complex mixtures of neurotoxins, enzymes, and other bioactive molecules that are produced by the venom glands of scorpions. These venoms are primarily used for prey immobilization and defense. The neurotoxins found in scorpion venoms can cause a variety of symptoms in humans, including pain, swelling, numbness, and in severe cases, respiratory failure and death.

Scorpion venoms are being studied for their potential medical applications, such as in the development of new pain medications and insecticides. Additionally, some components of scorpion venom have been found to have antimicrobial properties and may be useful in the development of new antibiotics.

Tetrodotoxin (TTX) is a potent neurotoxin that is primarily found in certain species of pufferfish, blue-ringed octopuses, and other marine animals. It blocks voltage-gated sodium channels in nerve cell membranes, leading to muscle paralysis and potentially respiratory failure. TTX has no known antidote, and medical treatment focuses on supportive care for symptoms. Exposure can occur through ingestion, inhalation, or skin absorption, depending on the route of toxicity.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Cyclic nucleotides are formed by the intramolecular phosphoester bond between the phosphate group and the hydroxyl group at the 3'-carbon atom of the ribose sugar in a nucleotide. This creates a cyclic structure, specifically a cyclic phosphate. The most common cyclic nucleotides are cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). These molecules function as second messengers in cells, playing crucial roles in various cellular signaling pathways related to metabolism, gene expression, and cell differentiation. The levels of cAMP and cGMP are tightly regulated by the activities of enzymes such as adenylate cyclase and guanylate cyclase for their synthesis, and phosphodiesterases for their degradation.

Calcium channels, Q-type, are a type of voltage-gated calcium channel found in various tissues, including the brain and heart. They are called "Q-type" because they exhibit a distinctive "q-wave" in their current trace during electrical activity. These channels play important roles in regulating physiological processes such as neurotransmitter release, hormone secretion, and cardiac muscle contraction.

The pore-forming subunit of Q-type calcium channels is the CaV2.1 (or α1A) subunit, which is encoded by the CACNA1A gene. These channels are activated by depolarization of the cell membrane and allow the influx of calcium ions into the cell. The resulting increase in intracellular calcium concentration triggers various downstream signaling pathways that mediate the physiological responses mentioned above.

Dysfunction of Q-type calcium channels has been implicated in several neurological and cardiovascular disorders, including migraine, epilepsy, cerebellar ataxia, and hypertension. Therefore, understanding the structure, function, and regulation of these channels is an important area of research for developing new therapeutic strategies to treat these conditions.

Delayed rectifier potassium channels are a type of ion channel found in the membrane of excitable cells, such as nerve and muscle cells. They are called "delayed rectifiers" because they activate and allow the flow of potassium ions (K+) out of the cell after a short delay following an action potential, or electrical signal.

These channels play a crucial role in regulating the duration and frequency of action potentials, helping to restore the resting membrane potential of the cell after it has fired. By allowing K+ to flow out of the cell, delayed rectifier potassium channels help to repolarize the membrane and bring it back to its resting state.

There are several different types of delayed rectifier potassium channels, which are classified based on their biophysical and pharmacological properties. These channels are important targets for drugs used to treat a variety of conditions, including cardiac arrhythmias, epilepsy, and psychiatric disorders.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Site-directed mutagenesis is a molecular biology technique used to introduce specific and targeted changes to a specific DNA sequence. This process involves creating a new variant of a gene or a specific region of interest within a DNA molecule by introducing a planned, deliberate change, or mutation, at a predetermined site within the DNA sequence.

The methodology typically involves the use of molecular tools such as PCR (polymerase chain reaction), restriction enzymes, and/or ligases to introduce the desired mutation(s) into a plasmid or other vector containing the target DNA sequence. The resulting modified DNA molecule can then be used to transform host cells, allowing for the production of large quantities of the mutated gene or protein for further study.

Site-directed mutagenesis is a valuable tool in basic research, drug discovery, and biotechnology applications where specific changes to a DNA sequence are required to understand gene function, investigate protein structure/function relationships, or engineer novel biological properties into existing genes or proteins.

Quaternary ammonium compounds (QACs) are a group of disinfectants and antiseptics that contain a nitrogen atom surrounded by four organic groups, resulting in a charged "quat" structure. They are widely used in healthcare settings due to their broad-spectrum activity against bacteria, viruses, fungi, and spores. QACs work by disrupting the cell membrane of microorganisms, leading to their death. Common examples include benzalkonium chloride and cetyltrimethylammonium bromide. It is important to note that some microorganisms have developed resistance to QACs, and they may not be effective against all types of pathogens.

NAV1.2, also known as SCN2A, is a type of voltage-gated sodium channel that is primarily expressed in the central nervous system, including the brain and spinal cord. Voltage-gated sodium channels are transmembrane proteins that play a crucial role in the generation and propagation of action potentials in excitable cells such as neurons.

NAV1.2 voltage-gated sodium channels are responsible for the initiation and early phase of action potentials in neurons. They are activated by depolarization of the membrane potential and allow the influx of sodium ions into the cell, which leads to a rapid depolarization of the membrane. This triggers the opening of additional voltage-gated sodium channels, leading to a regenerative response that results in the generation of an action potential.

Mutations in the SCN2A gene, which encodes the NAV1.2 channel, have been associated with various neurological disorders, including epilepsy, autism spectrum disorder, and intellectual disability. These mutations can alter the function of the NAV1.2 channel, leading to changes in neuronal excitability and network activity that contribute to the development of these disorders.

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

Biophysics is a interdisciplinary field that combines the principles and methods of physics with those of biology to study biological systems and phenomena. It involves the use of physical theories, models, and techniques to understand and explain the properties, functions, and behaviors of living organisms and their constituents, such as cells, proteins, and DNA.

Biophysics can be applied to various areas of biology, including molecular biology, cell biology, neuroscience, and physiology. It can help elucidate the mechanisms of biological processes at the molecular and cellular levels, such as protein folding, ion transport, enzyme kinetics, gene expression, and signal transduction. Biophysical methods can also be used to develop diagnostic and therapeutic tools for medical applications, such as medical imaging, drug delivery, and gene therapy.

Examples of biophysical techniques include X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, electron microscopy, fluorescence microscopy, atomic force microscopy, and computational modeling. These methods allow researchers to probe the structure, dynamics, and interactions of biological molecules and systems with high precision and resolution, providing insights into their functions and behaviors.

CHO cells, or Chinese Hamster Ovary cells, are a type of immortalized cell line that are commonly used in scientific research and biotechnology. They were originally derived from the ovaries of a female Chinese hamster (Cricetulus griseus) in the 1950s.

CHO cells have several characteristics that make them useful for laboratory experiments. They can grow and divide indefinitely under appropriate conditions, which allows researchers to culture large quantities of them for study. Additionally, CHO cells are capable of expressing high levels of recombinant proteins, making them a popular choice for the production of therapeutic drugs, vaccines, and other biologics.

In particular, CHO cells have become a workhorse in the field of biotherapeutics, with many approved monoclonal antibody-based therapies being produced using these cells. The ability to genetically modify CHO cells through various methods has further expanded their utility in research and industrial applications.

It is important to note that while CHO cells are widely used in scientific research, they may not always accurately represent human cell behavior or respond to drugs and other compounds in the same way as human cells do. Therefore, results obtained using CHO cells should be validated in more relevant systems when possible.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Cyclic guanosine monophosphate (cGMP) is a important second messenger molecule that plays a crucial role in various biological processes within the human body. It is synthesized from guanosine triphosphate (GTP) by the enzyme guanylyl cyclase.

Cyclic GMP is involved in regulating diverse physiological functions, such as smooth muscle relaxation, cardiovascular function, and neurotransmission. It also plays a role in modulating immune responses and cellular growth and differentiation.

In the medical field, changes in cGMP levels or dysregulation of cGMP-dependent pathways have been implicated in various disease states, including pulmonary hypertension, heart failure, erectile dysfunction, and glaucoma. Therefore, pharmacological agents that target cGMP signaling are being developed as potential therapeutic options for these conditions.

Purinergic P2X2 receptors are a type of ionotropic receptor, which are ligand-gated ion channels that open to allow the flow of ions across the cell membrane in response to the binding of a specific molecule (ligand). In the case of P2X2 receptors, the ligands are ATP and other purinergic agonists.

P2X2 receptors are composed of three subunits that assemble to form a functional ion channel. When ATP binds to the extracellular domain of the receptor, it triggers a conformational change that opens the channel, allowing cations such as calcium (Ca²+), sodium (Na⁺) and potassium (K⁺) to flow into the cell.

P2X2 receptors are widely expressed in both the peripheral and central nervous systems, where they play important roles in various physiological processes, including neurotransmission, pain perception, and vasoconstriction. They have also been implicated in several pathological conditions, such as chronic pain, epilepsy, and bladder dysfunction.

P2X2 receptors are of particular interest in pharmacology due to their potential as targets for drug development. For example, P2X2 receptor antagonists have been shown to be effective in reducing pain hypersensitivity in animal models of chronic pain.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Chelating agents are substances that can bind and form stable complexes with certain metal ions, preventing them from participating in chemical reactions. In medicine, chelating agents are used to remove toxic or excessive amounts of metal ions from the body. For example, ethylenediaminetetraacetic acid (EDTA) is a commonly used chelating agent that can bind with heavy metals such as lead and mercury, helping to eliminate them from the body and reduce their toxic effects. Other chelating agents include dimercaprol (BAL), penicillamine, and deferoxamine. These agents are used to treat metal poisoning, including lead poisoning, iron overload, and copper toxicity.

R-type calcium channels are a type of voltage-gated calcium channel found in excitable cells such as neurons and muscle cells. They are named "R" for "resistant," because they are less sensitive to blockers that inhibit other types of calcium channels. R-type calcium channels play important roles in various physiological processes, including regulation of neurotransmitter release, excitation-contraction coupling in muscle cells, and gene expression. They are composed of several subunits, including the pore-forming α1E subunit, which determines the channel's electrophysiological properties, and accessory subunits that modulate the channel's function. R-type calcium channels are activated by depolarization of the cell membrane and allow the influx of calcium ions into the cell, which can trigger various downstream signaling pathways.

Marine toxins are toxic compounds that are produced by certain marine organisms, including algae, bacteria, and various marine animals such as shellfish, jellyfish, and snails. These toxins can cause a range of illnesses and symptoms in humans who consume contaminated seafood or come into direct contact with the toxin-producing organisms. Some of the most well-known marine toxins include:

1. Saxitoxin: Produced by certain types of algae, saxitoxin can cause paralytic shellfish poisoning (PSP) in humans who consume contaminated shellfish. Symptoms of PSP include tingling and numbness of the lips, tongue, and fingers, followed by muscle weakness, paralysis, and in severe cases, respiratory failure.
2. Domoic acid: Produced by certain types of algae, domoic acid can cause amnesic shellfish poisoning (ASP) in humans who consume contaminated shellfish. Symptoms of ASP include nausea, vomiting, diarrhea, abdominal cramps, headache, and memory loss.
3. Okadaic acid: Produced by certain types of algae, okadaic acid can cause diarrhetic shellfish poisoning (DSP) in humans who consume contaminated shellfish. Symptoms of DSP include nausea, vomiting, diarrhea, abdominal cramps, and fever.
4. Ciguatoxin: Produced by certain types of dinoflagellates, ciguatoxin can cause ciguatera fish poisoning (CFP) in humans who consume contaminated fish. Symptoms of CFP include nausea, vomiting, diarrhea, abdominal pain, and neurological symptoms such as tingling and numbness of the lips, tongue, and fingers, as well as reversal of hot and cold sensations.
5. Tetrodotoxin: Found in certain types of pufferfish, tetrodotoxin can cause a severe form of food poisoning known as pufferfish poisoning or fugu poisoning. Symptoms of tetrodotoxin poisoning include numbness of the lips and tongue, difficulty speaking, muscle weakness, paralysis, and respiratory failure.

Prevention measures for these types of seafood poisoning include avoiding consumption of fish and shellfish that are known to be associated with these toxins, as well as cooking and preparing seafood properly before eating it. Additionally, monitoring programs have been established in many countries to monitor the levels of these toxins in seafood and issue warnings when necessary.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Spinal ganglia, also known as dorsal root ganglia, are clusters of nerve cell bodies located in the peripheral nervous system. They are situated along the length of the spinal cord and are responsible for transmitting sensory information from the body to the brain. Each spinal ganglion contains numerous neurons, or nerve cells, with long processes called axons that extend into the periphery and innervate various tissues and organs. The cell bodies within the spinal ganglia receive sensory input from these axons and transmit this information to the central nervous system via the dorsal roots of the spinal nerves. This allows the brain to interpret and respond to a wide range of sensory stimuli, including touch, temperature, pain, and proprioception (the sense of the position and movement of one's body).

Tetraethylammonium compounds refer to chemical substances that contain the tetraethylammonium cation (N(C2H5)4+). This organic cation is derived from tetraethylammonium hydroxide, which in turn is produced by the reaction of ethyl alcohol with ammonia and then treated with a strong acid.

Tetraethylammonium compounds are used in various biomedical research applications as they can block certain types of ion channels, making them useful for studying neuronal excitability and neurotransmission. However, these compounds have also been associated with toxic effects on the nervous system and other organs, and their use is therefore subject to strict safety regulations.

Cellular mechanotransduction is the process by which cells convert mechanical stimuli into biochemical signals, resulting in changes in cell behavior and function. This complex process involves various molecular components, including transmembrane receptors, ion channels, cytoskeletal proteins, and signaling molecules. Mechanical forces such as tension, compression, or fluid flow can activate these components, leading to alterations in gene expression, protein synthesis, and cell shape or movement. Cellular mechanotransduction plays a crucial role in various physiological processes, including tissue development, homeostasis, and repair, as well as in pathological conditions such as fibrosis and cancer progression.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

I apologize, but "estrenes" is not a term commonly used in medical terminology in English. It may be a term used in another language or context. If you could provide more context or clarify what you are looking for, I would be happy to help further.

Sodium channels are specialized protein structures that are embedded in the membranes of excitable cells, such as nerve and muscle cells. They play a crucial role in the generation and transmission of electrical signals in these cells. Sodium channels are responsible for the rapid influx of sodium ions into the cell during the initial phase of an action potential, which is the electrical signal that travels along the membrane of a neuron or muscle fiber. This sudden influx of sodium ions causes the membrane potential to rapidly reverse, leading to the depolarization of the cell. After the action potential, the sodium channels close and become inactivated, preventing further entry of sodium ions and helping to restore the resting membrane potential.

Sodium channels are composed of a large alpha subunit and one or two smaller beta subunits. The alpha subunit forms the ion-conducting pore, while the beta subunits play a role in modulating the function and stability of the channel. Mutations in sodium channel genes have been associated with various inherited diseases, including certain forms of epilepsy, cardiac arrhythmias, and muscle disorders.

Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.

In a medical context, electric stimulation may be used for various purposes such as:

1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.

It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.

Phosphatidylinositol 4,5-Diphosphate (PIP2) is a phospholipid molecule that plays a crucial role as a secondary messenger in various cell signaling pathways. It is a constituent of the inner leaflet of the plasma membrane and is formed by the phosphorylation of Phosphatidylinositol 4-Phosphate (PIP) at the 5th position of the inositol ring by enzyme Phosphoinositide kinase.

PIP2 is involved in several cellular processes, including regulation of ion channels, cytoskeleton dynamics, and membrane trafficking. It also acts as a substrate for the generation of two important secondary messengers, Inositol 1,4,5-Trisphosphate (IP3) and Diacylglycerol (DAG), which are produced by the action of Phospholipase C enzyme in response to various extracellular signals. These second messengers then mediate a variety of cellular responses such as calcium mobilization, gene expression, and cell proliferation.

Biophysical phenomena refer to the observable events and processes that occur in living organisms, which can be explained and studied using the principles and methods of physics. These phenomena can include a wide range of biological processes at various levels of organization, from molecular interactions to whole-organism behaviors. Examples of biophysical phenomena include the mechanics of muscle contraction, the electrical activity of neurons, the transport of molecules across cell membranes, and the optical properties of biological tissues. By applying physical theories and techniques to the study of living systems, biophysicists seek to better understand the fundamental principles that govern life and to develop new approaches for diagnosing and treating diseases.

Calmodulin is a small, ubiquitous calcium-binding protein that plays a critical role in various intracellular signaling pathways. It functions as a calcium sensor, binding to and regulating the activity of numerous target proteins upon calcium ion (Ca^2+^) binding. Calmodulin is expressed in all eukaryotic cells and participates in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, metabolism, and cell cycle progression.

The protein contains four EF-hand motifs that can bind Ca^2+^ ions. Upon calcium binding, conformational changes occur in the calmodulin structure, exposing hydrophobic surfaces that facilitate its interaction with target proteins. Calmodulin's targets include enzymes (such as protein kinases and phosphatases), ion channels, transporters, and cytoskeletal components. By modulating the activity of these proteins, calmodulin helps regulate essential cellular functions in response to changes in intracellular Ca^2+^ concentrations.

Calmodulin's molecular weight is approximately 17 kDa, and it consists of a single polypeptide chain with 148-150 amino acid residues. The protein can be found in both the cytoplasm and the nucleus of cells. In addition to its role as a calcium sensor, calmodulin has been implicated in various pathological conditions, including cancer, neurodegenerative diseases, and cardiovascular disorders.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

Mefenamic Acid is a non-steroidal anti-inflammatory drug (NSAID) commonly used for its analgesic, antipyretic, and anti-inflammatory properties. It works by inhibiting the enzyme cyclooxygenase (COX), which is responsible for prostaglandin synthesis, a key player in pain and inflammation processes.

Mefenamic Acid is primarily used to treat mild to moderate pain, including menstrual cramps, primary dysmenorrhea, post-operative pain, and various types of inflammatory conditions such as rheumatoid arthritis and osteoarthritis.

Common side effects may include gastrointestinal disturbances like nausea, vomiting, diarrhea, or abdominal pain. Long-term use of Mefenamic Acid has been associated with increased risks of cardiovascular events, gastrointestinal ulcers, and bleeding. Therefore, it is essential to follow the recommended dosage and consult a healthcare professional for appropriate usage and potential interactions with other medications.

Osmolar concentration is a measure of the total number of solute particles (such as ions or molecules) dissolved in a solution per liter of solvent (usually water), which affects the osmotic pressure. It is expressed in units of osmoles per liter (osmol/L). Osmolarity and osmolality are related concepts, with osmolarity referring to the number of osmoles per unit volume of solution, typically measured in liters, while osmolality refers to the number of osmoles per kilogram of solvent. In clinical contexts, osmolar concentration is often used to describe the solute concentration of bodily fluids such as blood or urine.

Channelopathies are genetic disorders that are caused by mutations in the genes that encode for ion channels. Ion channels are specialized proteins that regulate the flow of ions, such as sodium, potassium, and calcium, across cell membranes. These ion channels play a crucial role in various physiological processes, including the generation and transmission of electrical signals in the body.

Channelopathies can affect various organs and systems in the body, depending on the type of ion channel that is affected. For example, mutations in sodium channel genes can cause neuromuscular disorders such as epilepsy, migraine, and periodic paralysis. Mutations in potassium channel genes can cause cardiac arrhythmias, while mutations in calcium channel genes can cause neurological disorders such as episodic ataxia and hemiplegic migraine.

The symptoms of channelopathies can vary widely depending on the specific disorder and the severity of the mutation. Treatment typically involves managing the symptoms and may include medications, lifestyle modifications, or in some cases, surgery.

Protein isoforms are different forms or variants of a protein that are produced from a single gene through the process of alternative splicing, where different exons (or parts of exons) are included in the mature mRNA molecule. This results in the production of multiple, slightly different proteins that share a common core structure but have distinct sequences and functions. Protein isoforms can also arise from genetic variations such as single nucleotide polymorphisms or mutations that alter the protein-coding sequence of a gene. These differences in protein sequence can affect the stability, localization, activity, or interaction partners of the protein isoform, leading to functional diversity and specialization within cells and organisms.

Menthol is a compound obtained from the crystals of the mint plant (Mentha arvensis). It is a white, crystalline substance that is solid at room temperature but becomes a clear, colorless, oily liquid when heated. Menthol has a cooling and soothing effect on mucous membranes, which makes it a common ingredient in over-the-counter products used to relieve symptoms of congestion, coughs, and sore throats. It is also used as a topical analgesic for its pain-relieving properties and as a flavoring agent in various products such as toothpaste, mouthwashes, and candies.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

Type C phospholipases, also known as group CIA phospholipases or patatin-like phospholipase domain containing proteins (PNPLAs), are a subclass of phospholipases that specifically hydrolyze the sn-2 ester bond of glycerophospholipids. They belong to the PNPLA family, which includes nine members (PNPLA1-9) with diverse functions in lipid metabolism and cell signaling.

Type C phospholipases contain a patatin domain, which is a conserved region of approximately 240 amino acids that exhibits lipase and acyltransferase activities. These enzymes are primarily involved in the regulation of triglyceride metabolism, membrane remodeling, and cell signaling pathways.

PNPLA1 (adiponutrin) is mainly expressed in the liver and adipose tissue, where it plays a role in lipid droplet homeostasis and triglyceride hydrolysis. PNPLA2 (ATGL or desnutrin) is a key regulator of triglyceride metabolism, responsible for the initial step of triacylglycerol hydrolysis in adipose tissue and other tissues.

PNPLA3 (calcium-independent phospholipase A2 epsilon or iPLA2ε) is involved in membrane remodeling, arachidonic acid release, and cell signaling pathways. Mutations in PNPLA3 have been associated with an increased risk of developing nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease, and hepatic steatosis.

PNPLA4 (lipase maturation factor 1 or LMF1) is involved in the intracellular processing and trafficking of lipases, such as pancreatic lipase and hepatic lipase. PNPLA5 ( Mozart1 or GSPML) has been implicated in membrane trafficking and cell signaling pathways.

PNPLA6 (neuropathy target esterase or NTE) is primarily expressed in the brain, where it plays a role in maintaining neuronal integrity by regulating lipid metabolism. Mutations in PNPLA6 have been associated with neuropathy and cognitive impairment.

PNPLA7 (adiponutrin or ADPN) has been implicated in lipid droplet formation, triacylglycerol hydrolysis, and cell signaling pathways. Mutations in PNPLA7 have been associated with an increased risk of developing NAFLD and hepatic steatosis.

PNPLA8 (diglyceride lipase or DGLα) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA9 (calcium-independent phospholipase A2 gamma or iPLA2γ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA10 (calcium-independent phospholipase A2 delta or iPLA2δ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA11 (calcium-independent phospholipase A2 epsilon or iPLA2ε) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA12 (calcium-independent phospholipase A2 zeta or iPLA2ζ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA13 (calcium-independent phospholipase A2 eta or iPLA2η) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA14 (calcium-independent phospholipase A2 theta or iPLA2θ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA15 (calcium-independent phospholipase A2 iota or iPLA2ι) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA16 (calcium-independent phospholipase A2 kappa or iPLA2κ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA17 (calcium-independent phospholipase A2 lambda or iPLA2λ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA18 (calcium-independent phospholipase A2 mu or iPLA2μ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA19 (calcium-independent phospholipase A2 nu or iPLA2ν) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA20 (calcium-independent phospholipase A2 xi or iPLA2ξ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA21 (calcium-independent phospholipase A2 omicron or iPLA2ο) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA22 (calcium-independent phospholipase A2 pi or iPLA2π) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA23 (calcium-independent phospholipase A2 rho or iPLA2ρ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA24 (calcium-independent phospholipase A2 sigma or iPLA2σ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA25 (calcium-independent phospholipase A2 tau or iPLA2τ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA26 (calcium-independent phospholipase A2 upsilon or iPLA2υ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA27 (calcium-independent phospholipase A2 phi or iPLA2φ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA28 (calcium-independent phospholipase A2 chi or iPLA2χ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA29 (calcium-independent phospholipase A2 psi or iPLA2ψ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA30 (calcium-independent phospholipase A2 omega or iPLA2ω) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA31 (calcium-independent phospholipase A2 pi or iPLA2π) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA32 (calcium-independent phospholipase A2 rho or iPLA2ρ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA33 (calcium-independent phospholipase A2 sigma or iPLA2σ) has been implicated in membrane remodeling, ar

Cell size refers to the volume or spatial dimensions of a cell, which can vary widely depending on the type and function of the cell. In general, eukaryotic cells (cells with a true nucleus) tend to be larger than prokaryotic cells (cells without a true nucleus). The size of a cell is determined by various factors such as genetic makeup, the cell's role in the organism, and its environment.

The study of cell size and its relationship to cell function is an active area of research in biology, with implications for our understanding of cellular processes, evolution, and disease. For example, changes in cell size have been linked to various pathological conditions, including cancer and neurodegenerative disorders. Therefore, measuring and analyzing cell size can provide valuable insights into the health and function of cells and tissues.

'4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid' is a chemical compound that is often used in research and scientific studies. Its molecular formula is C14H10N2O6S2. This compound is a derivative of stilbene, which is a type of organic compound that consists of two phenyl rings joined by a ethylene bridge. In '4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid', the hydrogen atoms on the carbon atoms of the ethylene bridge have been replaced with isothiocyanate groups (-N=C=S), and the phenyl rings have been sulfonated (introduction of a sulfuric acid group, -SO3H) to increase its water solubility.

This compound is often used as a fluorescent probe in biochemical and cell biological studies due to its ability to form covalent bonds with primary amines, such as those found on proteins. This property allows researchers to label and track specific proteins or to measure the concentration of free primary amines in a sample.

It is important to note that '4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid' is a hazardous chemical and should be handled with care, using appropriate personal protective equipment and safety measures.

Sulfonylurea receptors (SURs) are a type of transmembrane protein found in the beta cells of the pancreas. They are part of the ATP-sensitive potassium (KATP) channel complex, which plays a crucial role in regulating insulin secretion.

SURs have two subtypes, SUR1 and SUR2, which are associated with different KATP channel subunits. SUR1 is primarily found in the pancreas and brain, while SUR2 is expressed in various tissues, including skeletal muscle and heart.

Sulfonylurea drugs, used to treat type 2 diabetes, bind to SURs and stimulate insulin secretion by closing the KATP channel, which leads to membrane depolarization and subsequent calcium influx, triggering insulin release from beta cells.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Smooth muscle, also known as involuntary muscle, is a type of muscle that is controlled by the autonomic nervous system and functions without conscious effort. These muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels, as well as in the eyes, skin, and other areas of the body.

Smooth muscle fibers are shorter and narrower than skeletal muscle fibers and do not have striations or sarcomeres, which give skeletal muscle its striped appearance. Smooth muscle is controlled by the autonomic nervous system through the release of neurotransmitters such as acetylcholine and norepinephrine, which bind to receptors on the smooth muscle cells and cause them to contract or relax.

Smooth muscle plays an important role in many physiological processes, including digestion, circulation, respiration, and elimination. It can also contribute to various medical conditions, such as hypertension, gastrointestinal disorders, and genitourinary dysfunction, when it becomes overactive or underactive.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Voltage-gated sodium channels are specialized protein complexes found in the membranes of excitable cells, such as neurons and muscle cells. They play a crucial role in the generation and propagation of action potentials, which are the electrical signals that allow these cells to communicate and coordinate their activities.

Structurally, voltage-gated sodium channels consist of a large alpha subunit that forms the ion-conducting pore, as well as one or more beta subunits that modulate the channel's properties. The alpha subunit contains four repeating domains (I-IV), each of which contains six transmembrane segments (S1-S6).

The channel is closed at resting membrane potentials but can be activated by depolarization of the membrane, leading to the opening of the pore and the rapid influx of sodium ions into the cell. This influx of positive charges further depolarizes the membrane, leading to the activation of additional voltage-gated sodium channels and the propagation of the action potential along the cell membrane.

Voltage-gated sodium channels are critical for normal physiological processes such as nerve impulse transmission and muscle contraction. However, mutations in these channels can lead to a variety of channelopathies, including inherited neurological disorders such as epilepsy and peripheral neuropathy. Additionally, certain drugs and toxins can target voltage-gated sodium channels, leading to altered electrical activity in excitable cells and potential toxicity or therapeutic effects.

Cholinergic agonists are substances that bind to and activate cholinergic receptors, which are neuroreceptors that respond to the neurotransmitter acetylcholine. These agents can mimic the effects of acetylcholine in the body and are used in medical treatment to produce effects such as pupil constriction, increased gastrointestinal motility, bronchodilation, and improved cognition. Examples of cholinergic agonists include pilocarpine, bethanechol, and donepezil.

Charybdotoxin is a neurotoxin that is derived from the venom of the death stalker scorpion (Leiurus quinquestriatus). It specifically binds to and blocks certain types of ion channels called "big potassium" or "BK" channels, which are found in various tissues including smooth muscle, nerve, and endocrine cells. By blocking these channels, charybdotoxin can alter the electrical activity of cells and potentially affect a variety of physiological processes. It is an important tool in basic research for studying the structure and function of BK channels and their role in various diseases.

Voltage-Dependent Anion Channels (VDACs) are large protein channels found in the outer mitochondrial membrane. They play a crucial role in the regulation of metabolite and ion exchange between the cytosol and the mitochondria. VDACs are permeable to anions such as chloride, phosphate, and bicarbonate ions, as well as to small molecules and metabolites like ATP, ADP, NADH, and others.

The voltage-dependent property of these channels arises from the fact that their permeability can be modulated by changes in the membrane potential across the outer mitochondrial membrane. At low membrane potentials, VDACs are predominantly open and facilitate the flow of metabolites and ions. However, as the membrane potential becomes more positive, VDACs can transition to a closed or partially closed state, which restricts ion and metabolite movement.

VDACs have been implicated in various cellular processes, including apoptosis, calcium homeostasis, and energy metabolism. Dysregulation of VDAC function has been associated with several pathological conditions, such as neurodegenerative diseases, cancer, and ischemia-reperfusion injury.

Cadmium is a toxic heavy metal that is a byproduct of the mining and smelting of zinc, lead, and copper. It has no taste or smell and can be found in small amounts in air, water, and soil. Cadmium can also be found in some foods, such as kidneys, liver, and shellfish.

Exposure to cadmium can cause a range of health effects, including kidney damage, lung disease, fragile bones, and cancer. Cadmium is classified as a known human carcinogen by the International Agency for Research on Cancer (IARC) and the National Toxicology Program (NTP).

Occupational exposure to cadmium can occur in industries that produce or use cadmium, such as battery manufacturing, metal plating, and pigment production. Workers in these industries may be exposed to cadmium through inhalation of cadmium-containing dusts or fumes, or through skin contact with cadmium-containing materials.

The general population can also be exposed to cadmium through the environment, such as by eating contaminated food or breathing secondhand smoke. Smoking is a major source of cadmium exposure for smokers and those exposed to secondhand smoke.

Prevention measures include reducing occupational exposure to cadmium, controlling emissions from industrial sources, and reducing the use of cadmium in consumer products. Regular monitoring of air, water, and soil for cadmium levels can also help identify potential sources of exposure and prevent health effects.

I'm sorry for any confusion, but "Nickel" is not a medical term. It is a chemical element with the symbol Ni and atomic number 28. Nickel is a hard, silvery-white lustrous metal with a slight golden tinge. It is one of four elements that are ferromagnetic and is used as a common component in various alloys due to its properties such as resistance to corrosion and heat.

However, in a medical context, nickel may refer to:

* Nickel allergy: A type of allergic contact dermatitis caused by an immune system response to the presence of nickel in jewelry, clothing fasteners, or other items that come into contact with the skin. Symptoms can include redness, itching, and rash at the site of exposure.
* Nickel carbonyl: A highly toxic chemical compound (Ni(CO)4) that can cause respiratory and neurological problems if inhaled. It is produced during some industrial processes involving nickel and carbon monoxide and poses a health risk to workers if proper safety measures are not taken.

If you have any concerns about exposure to nickel or symptoms related to nickel allergy, it's best to consult with a healthcare professional for further evaluation and treatment.

Dihydropyridines are a class of compounds that contain a core structure of two fused rings, each containing six carbon atoms, with a hydrogen atom attached to each of the two central carbon atoms. They are commonly used in pharmaceuticals, particularly as calcium channel blockers in the treatment of cardiovascular diseases.

Calcium channel blockers, including dihydropyridines, work by blocking the influx of calcium ions into cardiac and vascular smooth muscle cells. This leads to relaxation of the muscles, resulting in decreased peripheral resistance and reduced blood pressure. Dihydropyridines are known for their potent vasodilatory effects and include medications such as nifedipine, amlodipine, and felodipine.

It is important to note that while dihydropyridines can be effective in treating hypertension and angina, they may also have side effects such as headache, dizziness, and peripheral edema. Additionally, they may interact with other medications, so it is essential to consult a healthcare provider before starting or changing any medication regimen.

Potassium channels are membrane proteins that play a crucial role in regulating the electrical excitability of cells, including cardiac, neuronal, and muscle cells. These channels facilitate the selective passage of potassium ions (K+) across the cell membrane, maintaining the resting membrane potential and shaping action potentials. They are composed of four or six subunits that assemble to form a central pore through which potassium ions move down their electrochemical gradient. Potassium channels can be modulated by various factors such as voltage, ligands, mechanical stimuli, or temperature, allowing cells to fine-tune their electrical properties and respond to different physiological demands. Dysfunction of potassium channels has been implicated in several diseases, including cardiac arrhythmias, epilepsy, and neurodegenerative disorders.

I apologize, but I am not able to provide a medical definition for "Egtazic Acid" because it is not a term that is recognized in the field of medicine or pharmacology. It is possible that you may have meant "Egтарic Acid," which also does not have a specific medical meaning, or "Ethylene Glycol Tetraacetic Acid (EGTA)," which is a chemical compound used in research and medicine for its ability to bind calcium ions. If you have any other questions, I would be happy to try to help answer them.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

Lithium is not a medical term per se, but it is a chemical element with symbol Li and atomic number 3. In the field of medicine, lithium is most commonly referred to as a medication, specifically as "lithium carbonate" or "lithium citrate," which are used primarily to treat bipolar disorder. These medications work by stabilizing mood and reducing the severity and frequency of manic episodes.

Lithium is a naturally occurring substance, and it is an alkali metal. In its elemental form, lithium is highly reactive and flammable. However, when combined with carbonate or citrate ions to form lithium salts, it becomes more stable and safe for medical use.

It's important to note that lithium levels in the body must be closely monitored while taking this medication because too much lithium can lead to toxicity, causing symptoms such as tremors, nausea, diarrhea, and in severe cases, seizures, coma, or even death. Regular blood tests are necessary to ensure that lithium levels remain within the therapeutic range.

In the context of medicine, particularly in relation to cancer treatment, protons refer to positively charged subatomic particles found in the nucleus of an atom. Proton therapy, a type of radiation therapy, uses a beam of protons to target and destroy cancer cells with high precision, minimizing damage to surrounding healthy tissue. The concentrated dose of radiation is delivered directly to the tumor site, reducing side effects and improving quality of life during treatment.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Pyrrolidinones are a class of organic compounds that contain a pyrrolidinone ring, which is a five-membered ring containing four carbon atoms and one nitrogen atom. The nitrogen atom is part of an amide functional group, which consists of a carbonyl (C=O) group bonded to a nitrogen atom.

Pyrrolidinones are commonly found in various natural and synthetic compounds, including pharmaceuticals, agrochemicals, and materials. They exhibit a wide range of biological activities, such as anti-inflammatory, antiviral, and anticancer properties. Some well-known drugs that contain pyrrolidinone rings include the pain reliever tramadol, the muscle relaxant cyclobenzaprine, and the antipsychotic aripiprazole.

Pyrrolidinones can be synthesized through various chemical reactions, such as the cyclization of γ-amino acids or the reaction of α-amino acids with isocyanates. The unique structure and reactivity of pyrrolidinones make them valuable intermediates in organic synthesis and drug discovery.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Muscle cells, also known as muscle fibers, are specialized cells that have the ability to contract and generate force, allowing for movement of the body and various internal organ functions. There are three main types of muscle tissue: skeletal, cardiac, and smooth.

Skeletal muscle cells are voluntary striated muscles attached to bones, enabling body movements and posture. They are multinucleated, with numerous nuclei located at the periphery of the cell. These cells are often called muscle fibers and can be quite large, extending the entire length of the muscle.

Cardiac muscle cells form the contractile tissue of the heart. They are also striated but have a single nucleus per cell and are interconnected by specialized junctions called intercalated discs, which help coordinate contraction throughout the heart.

Smooth muscle cells are found in various internal organs such as the digestive, respiratory, and urinary tracts, blood vessels, and the reproductive system. They are involuntary, non-striated muscles that control the internal organ functions. Smooth muscle cells have a single nucleus per cell and can either be spindle-shaped or stellate (star-shaped).

In summary, muscle cells are specialized contractile cells responsible for movement and various internal organ functions in the human body. They can be categorized into three types: skeletal, cardiac, and smooth, based on their structure, location, and function.

The Lanthanoid series, also known as the lanthanides, refers to the 15 metallic chemical elements in the periodic table that make up row 6 of the f-block. These elements include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

These elements are characterized by having similar properties, including being soft, silvery-white, highly reactive, and divalent or trivalent in their chemical behavior. They have incompletely filled f orbitals, which results in unique magnetic and optical properties that make them useful in various applications, such as magnets, batteries, and phosphors.

The lanthanoid series elements are often extracted from minerals such as monazite and bastnasite, and their production involves complex chemical processes to separate them from each other. Due to their similar properties, this separation can be challenging and requires significant expertise and resources.

Diltiazem is a calcium channel blocker medication that is used to treat hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders. It works by relaxing the muscles of the blood vessels, which lowers blood pressure and improves blood flow to the heart. Diltiazem may also be used to reduce the risk of heart attack in patients with coronary artery disease.

The medication is available in various forms, including immediate-release tablets, extended-release tablets, and extended-release capsules. It is usually taken orally, one to three times a day, depending on the formulation and the individual patient's needs. Diltiazem may cause side effects such as dizziness, headache, nausea, and constipation.

It is important to follow the dosage instructions provided by your healthcare provider and to inform them of any other medications you are taking, as well as any medical conditions you have, before starting diltiazem.

Sensory receptor cells are specialized structures that convert physical stimuli from our environment into electrical signals, which are then transmitted to the brain for interpretation. These receptors can be found in various tissues throughout the body and are responsible for detecting sensations such as touch, pressure, temperature, taste, and smell. They can be classified into two main types: exteroceptors, which respond to stimuli from the external environment, and interoceptors, which react to internal conditions within the body. Examples of sensory receptor cells include hair cells in the inner ear, photoreceptors in the eye, and taste buds on the tongue.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Osmotic pressure is a fundamental concept in the field of physiology and biochemistry. It refers to the pressure that is required to be applied to a solution to prevent the flow of solvent (like water) into it, through a semi-permeable membrane, when the solution is separated from a pure solvent or a solution of lower solute concentration.

In simpler terms, osmotic pressure is the force that drives the natural movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration, across a semi-permeable membrane. This process is crucial for maintaining the fluid balance and nutrient transport in living organisms.

The osmotic pressure of a solution can be determined by its solute concentration, temperature, and the ideal gas law. It is often expressed in units of atmospheres (atm), millimeters of mercury (mmHg), or pascals (Pa). In medical contexts, understanding osmotic pressure is essential for managing various clinical conditions such as dehydration, fluid and electrolyte imbalances, and dialysis treatments.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

The extracellular space is the region outside of cells within a tissue or organ, where various biological molecules and ions exist in a fluid medium. This space is filled with extracellular matrix (ECM), which includes proteins like collagen and elastin, glycoproteins, and proteoglycans that provide structural support and biochemical cues to surrounding cells. The ECM also contains various ions, nutrients, waste products, signaling molecules, and growth factors that play crucial roles in cell-cell communication, tissue homeostasis, and regulation of cell behavior. Additionally, the extracellular space includes the interstitial fluid, which is the fluid component of the ECM, and the lymphatic and vascular systems, through which cells exchange nutrients, waste products, and signaling molecules with the rest of the body. Overall, the extracellular space is a complex and dynamic microenvironment that plays essential roles in maintaining tissue structure, function, and homeostasis.

Electrophysiological phenomena refer to the electrical properties and activities of biological tissues, cells, or organ systems, particularly in relation to nerve and muscle function. These phenomena can be studied using various techniques such as electrocardiography (ECG), electromyography (EMG), and electroencephalography (EEG).

In the context of cardiology, electrophysiological phenomena are often used to describe the electrical activity of the heart. The ECG is a non-invasive test that measures the electrical activity of the heart as it contracts and relaxes. By analyzing the patterns of electrical activity, doctors can diagnose various heart conditions such as arrhythmias, myocardial infarction, and electrolyte imbalances.

In neurology, electrophysiological phenomena are used to study the electrical activity of the brain. The EEG is a non-invasive test that measures the electrical activity of the brain through sensors placed on the scalp. By analyzing the patterns of electrical activity, doctors can diagnose various neurological conditions such as epilepsy, sleep disorders, and brain injuries.

Overall, electrophysiological phenomena are an important tool in medical diagnostics and research, providing valuable insights into the function of various organ systems.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Muscarinic agonists are a type of medication that binds to and activates muscarinic acetylcholine receptors, which are found in various organ systems throughout the body. These receptors are activated naturally by the neurotransmitter acetylcholine, and when muscarinic agonists bind to them, they mimic the effects of acetylcholine.

Muscarinic agonists can have a range of effects on different organ systems, depending on which receptors they activate. For example, they may cause bronchodilation (opening up of the airways) in the respiratory system, decreased heart rate and blood pressure in the cardiovascular system, increased glandular secretions in the gastrointestinal and salivary systems, and relaxation of smooth muscle in the urinary and reproductive systems.

Some examples of muscarinic agonists include pilocarpine, which is used to treat dry mouth and glaucoma, and bethanechol, which is used to treat urinary retention. It's important to note that muscarinic agonists can also have side effects, such as sweating, nausea, vomiting, and diarrhea, due to their activation of receptors in various organ systems.

An anion is an ion that has a negative electrical charge because it has more electrons than protons. The term "anion" is derived from the Greek word "anion," which means "to go up" or "to move upward." This name reflects the fact that anions are attracted to positively charged electrodes, or anodes, and will move toward them during electrolysis.

Anions can be formed when a neutral atom or molecule gains one or more extra electrons. For example, if a chlorine atom gains an electron, it becomes a chloride anion (Cl-). Anions are important in many chemical reactions and processes, including the conduction of electricity through solutions and the formation of salts.

In medicine, anions may be relevant in certain physiological processes, such as acid-base balance. For example, the concentration of anions such as bicarbonate (HCO3-) and chloride (Cl-) in the blood can affect the pH of the body fluids and help maintain normal acid-base balance. Abnormal levels of anions may indicate the presence of certain medical conditions, such as metabolic acidosis or alkalosis.

Meglumine is not a medical condition but a medication. It is an anticholinergic drug that is used as a diagnostic aid in the form of meglumine iodide, which is used to test for kidney function and to visualize the urinary tract. Meglumine is an amino sugar that is used as a counterion to combine with iodine to make meglumine iodide. It works by increasing the excretion of iodine through the kidneys, which helps to enhance the visibility of the urinary tract during imaging studies.

Mechanoreceptors are specialized sensory receptor cells that convert mechanical stimuli such as pressure, tension, or deformation into electrical signals that can be processed and interpreted by the nervous system. They are found in various tissues throughout the body, including the skin, muscles, tendons, joints, and internal organs. Mechanoreceptors can detect different types of mechanical stimuli depending on their specific structure and location. For example, Pacinian corpuscles in the skin respond to vibrations, while Ruffini endings in the joints detect changes in joint angle and pressure. Overall, mechanoreceptors play a crucial role in our ability to perceive and interact with our environment through touch, proprioception (the sense of the position and movement of body parts), and visceral sensation (awareness of internal organ activity).

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

NAV1.4, also known as SCN4A, is a gene that encodes for the α subunit of the voltage-gated sodium channel in humans. This channel, specifically located in the skeletal muscle, is responsible for the rapid influx of sodium ions during the initiation and propagation of action potentials, which are critical for muscle contraction.

The NAV1.4 Voltage-Gated Sodium Channel plays a crucial role in the functioning of skeletal muscles. Mutations in this gene can lead to various neuromuscular disorders such as hyperkalemic periodic paralysis, paramyotonia congenita, and potassium-aggravated myotonia, which are characterized by muscle stiffness, cramps, and episodes of weakness or paralysis.

Ortho-Aminobenzoates are chemical compounds that contain a benzene ring substituted with an amino group in the ortho position and an ester group in the form of a benzoate. They are often used as pharmaceutical intermediates, plastic additives, and UV stabilizers. In medical contexts, one specific ortho-aminobenzoate, para-aminosalicylic acid (PABA), is an antibiotic used in the treatment of tuberculosis. However, it's important to note that "ortho-aminobenzoates" in general do not have a specific medical definition and can refer to any compound with this particular substitution pattern on a benzene ring.

Caffeine is a central nervous system stimulant that occurs naturally in the leaves, seeds, or fruits of some plants. It can also be produced artificially and added to various products, such as food, drinks, and medications. Caffeine has a number of effects on the body, including increasing alertness, improving mood, and boosting energy levels.

In small doses, caffeine is generally considered safe for most people. However, consuming large amounts of caffeine can lead to negative side effects, such as restlessness, insomnia, rapid heart rate, and increased blood pressure. It is also possible to become dependent on caffeine, and withdrawal symptoms can occur if consumption is suddenly stopped.

Caffeine is found in a variety of products, including coffee, tea, chocolate, energy drinks, and some medications. The amount of caffeine in these products can vary widely, so it is important to pay attention to serving sizes and labels to avoid consuming too much.

The sarcoplasmic reticulum (SR) is a specialized type of smooth endoplasmic reticulum found in muscle cells, particularly in striated muscles such as skeletal and cardiac muscles. It is a complex network of tubules that surrounds the myofibrils, the contractile elements of the muscle fiber.

The primary function of the sarcoplasmic reticulum is to store calcium ions (Ca2+) and regulate their release during muscle contraction and uptake during muscle relaxation. The SR contains a high concentration of calcium-binding proteins, such as calsequestrin, which help to maintain this storage.

The release of calcium ions from the sarcoplasmic reticulum is triggered by an action potential that travels along the muscle fiber's sarcolemma and into the muscle fiber's interior (the sarcoplasm). This action potential causes the voltage-gated calcium channels in the SR membrane, known as ryanodine receptors, to open, releasing Ca2+ ions into the sarcoplasm.

The increased concentration of Ca2+ ions in the sarcoplasm triggers muscle contraction by binding to troponin, a protein associated with actin filaments, causing a conformational change that exposes the active sites on actin for myosin heads to bind and generate force.

After muscle contraction, the calcium ions must be actively transported back into the sarcoplasmic reticulum by Ca2+ ATPase pumps, also known as sarco(endo)plasmic reticulum calcium ATPases (SERCAs). This process helps to lower the concentration of Ca2+ in the sarcoplasm and allows the muscle fiber to relax.

Overall, the sarcoplasmic reticulum plays a crucial role in excitation-contraction coupling, the process by which action potentials trigger muscle contraction.

Thermosensing refers to the ability of living organisms to detect and respond to changes in temperature. This is achieved through specialized proteins called thermosensors, which are capable of converting thermal energy into chemical or electrical signals that can be interpreted by the organism's nervous system. Thermosensing plays a critical role in regulating various physiological processes, such as body temperature, metabolism, and development. In medicine, understanding thermosensing mechanisms can provide insights into the treatment of conditions associated with impaired temperature regulation, such as fever or hypothermia.

Muscarinic receptors are a type of G protein-coupled receptor (GPCR) that bind to the neurotransmitter acetylcholine. They are found in various organ systems, including the nervous system, cardiovascular system, and respiratory system. Muscarinic receptors are activated by muscarine, a type of alkaloid found in certain mushrooms, and are classified into five subtypes (M1-M5) based on their pharmacological properties and signaling pathways.

Muscarinic receptors play an essential role in regulating various physiological functions, such as heart rate, smooth muscle contraction, glandular secretion, and cognitive processes. Activation of M1, M3, and M5 muscarinic receptors leads to the activation of phospholipase C (PLC) and the production of inositol trisphosphate (IP3) and diacylglycerol (DAG), which increase intracellular calcium levels and activate protein kinase C (PKC). Activation of M2 and M4 muscarinic receptors inhibits adenylyl cyclase, reducing the production of cAMP and modulating ion channel activity.

In summary, muscarinic receptors are a type of GPCR that binds to acetylcholine and regulates various physiological functions in different organ systems. They are classified into five subtypes based on their pharmacological properties and signaling pathways.

Spider venoms are complex mixtures of bioactive compounds produced by the specialized glands of spiders. These venoms are primarily used for prey immobilization and defense. They contain a variety of molecules such as neurotoxins, proteases, peptides, and other biologically active substances. Different spider species have unique venom compositions, which can cause different reactions when they bite or come into contact with humans or other animals. Some spider venoms can cause mild symptoms like pain and swelling, while others can lead to more severe reactions such as tissue necrosis or even death in extreme cases.

Protein Kinase C (PKC) is a family of serine-threonine kinases that play crucial roles in various cellular signaling pathways. These enzymes are activated by second messengers such as diacylglycerol (DAG) and calcium ions (Ca2+), which result from the activation of cell surface receptors like G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs).

Once activated, PKC proteins phosphorylate downstream target proteins, thereby modulating their activities. This regulation is involved in numerous cellular processes, including cell growth, differentiation, apoptosis, and membrane trafficking. There are at least 10 isoforms of PKC, classified into three subfamilies based on their second messenger requirements and structural features: conventional (cPKC; α, βI, βII, and γ), novel (nPKC; δ, ε, η, and θ), and atypical (aPKC; ζ and ι/λ). Dysregulation of PKC signaling has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Protein transport, in the context of cellular biology, refers to the process by which proteins are actively moved from one location to another within or between cells. This is a crucial mechanism for maintaining proper cell function and regulation.

Intracellular protein transport involves the movement of proteins within a single cell. Proteins can be transported across membranes (such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, or plasma membrane) via specialized transport systems like vesicles and transport channels.

Intercellular protein transport refers to the movement of proteins from one cell to another, often facilitated by exocytosis (release of proteins in vesicles) and endocytosis (uptake of extracellular substances via membrane-bound vesicles). This is essential for communication between cells, immune response, and other physiological processes.

It's important to note that any disruption in protein transport can lead to various diseases, including neurological disorders, cancer, and metabolic conditions.

Imidazoles are a class of heterocyclic organic compounds that contain a double-bonded nitrogen atom and two additional nitrogen atoms in the ring. They have the chemical formula C3H4N2. In a medical context, imidazoles are commonly used as antifungal agents. Some examples of imidazole-derived antifungals include clotrimazole, miconazole, and ketoconazole. These medications work by inhibiting the synthesis of ergosterol, a key component of fungal cell membranes, leading to increased permeability and death of the fungal cells. Imidazoles may also have anti-inflammatory, antibacterial, and anticancer properties.

Ionophores are compounds that have the ability to form complexes with ions and facilitate their transportation across biological membranes. They can be either organic or inorganic molecules, and they play important roles in various physiological processes, including ion homeostasis, signal transduction, and antibiotic activity. In medicine and research, ionophores are used as tools to study ion transport, modulate cellular functions, and as therapeutic agents, especially in the treatment of bacterial and fungal infections.

Inositol 1,4,5-trisphosphate (IP3) is a intracellular signaling molecule that plays a crucial role in the release of calcium ions from the endoplasmic reticulum into the cytoplasm. It is a second messenger, which means it relays signals received by a cell's surface receptors to various effector proteins within the cell. IP3 is produced through the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) by activated phospholipase C (PLC) enzymes in response to extracellular signals such as hormones and neurotransmitters. The binding of IP3 to its receptor on the endoplasmic reticulum triggers the release of calcium ions, which then activates various cellular processes like gene expression, metabolism, and muscle contraction.

Secondary protein structure refers to the local spatial arrangement of amino acid chains in a protein, typically described as regular repeating patterns held together by hydrogen bonds. The two most common types of secondary structures are the alpha-helix (α-helix) and the beta-pleated sheet (β-sheet). In an α-helix, the polypeptide chain twists around itself in a helical shape, with each backbone atom forming a hydrogen bond with the fourth amino acid residue along the chain. This forms a rigid rod-like structure that is resistant to bending or twisting forces. In β-sheets, adjacent segments of the polypeptide chain run parallel or antiparallel to each other and are connected by hydrogen bonds, forming a pleated sheet-like arrangement. These secondary structures provide the foundation for the formation of tertiary and quaternary protein structures, which determine the overall three-dimensional shape and function of the protein.

Acetylcholine is a neurotransmitter, a type of chemical messenger that transmits signals across a chemical synapse from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell. It is involved in both peripheral and central nervous system functions.

In the peripheral nervous system, acetylcholine acts as a neurotransmitter at the neuromuscular junction, where it transmits signals from motor neurons to activate muscles. Acetylcholine also acts as a neurotransmitter in the autonomic nervous system, where it is involved in both the sympathetic and parasympathetic systems.

In the central nervous system, acetylcholine plays a role in learning, memory, attention, and arousal. Disruptions in cholinergic neurotransmission have been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, and myasthenia gravis.

Acetylcholine is synthesized from choline and acetyl-CoA by the enzyme choline acetyltransferase and is stored in vesicles at the presynaptic terminal of the neuron. When a nerve impulse arrives, the vesicles fuse with the presynaptic membrane, releasing acetylcholine into the synapse. The acetylcholine then binds to receptors on the postsynaptic membrane, triggering a response in the target cell. Acetylcholine is subsequently degraded by the enzyme acetylcholinesterase, which terminates its action and allows for signal transduction to be repeated.

4-Aminopyridine is a type of medication that is used to treat symptoms of certain neurological disorders, such as multiple sclerosis or spinal cord injuries. It works by blocking the action of potassium channels in nerve cells, which helps to improve the transmission of nerve impulses and enhance muscle function.

The chemical name for 4-Aminopyridine is 4-AP or fampridine. It is available as a prescription medication in some countries and can be taken orally in the form of tablets or capsules. Common side effects of 4-Aminopyridine include dizziness, lightheadedness, and numbness or tingling sensations in the hands or feet.

It is important to note that 4-Aminopyridine should only be used under the supervision of a healthcare professional, as it can have serious side effects if not used properly.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Mollusk venoms are toxic substances produced by certain species of mollusks, a group of marine animals that includes snails, slugs, clams, octopuses, and squids. These venoms are primarily used for defense against predators or for hunting prey. They can contain a variety of bioactive molecules, such as proteins, peptides, and neurotoxins, which can cause a range of effects on the victim's body, from mild irritation to paralysis and death.

One well-known example of a mollusk venom is that of the cone snail, which uses its venom to capture prey. The venom of some cone snails contains compounds called conotoxins, which are highly selective for specific ion channels in the nervous system and can cause paralysis or death in their victims. These conotoxins have been studied for their potential therapeutic applications, such as pain relief and treatment for neurological disorders.

It's important to note that while some mollusk venoms can be dangerous or even deadly to humans, most species of mollusks are not harmful to people. However, it's always a good idea to exercise caution when handling any marine animals, as even non-venomous species can cause injury with their sharp shells or other structures.

Sodium channel agonists are substances that enhance the activity or function of sodium channels. Sodium channels are membrane proteins that play a crucial role in the generation and transmission of electrical signals in excitable cells, such as nerve and muscle cells. They allow the influx of sodium ions into the cell, which leads to the depolarization of the cell membrane and the initiation of an action potential.

Sodium channel agonists increase the likelihood, duration, or amplitude of action potentials by promoting the opening of sodium channels or slowing their closure. These effects can have various physiological consequences depending on the type of cell and tissue involved. In some cases, sodium channel agonists may be used for therapeutic purposes, such as in the treatment of certain types of heart arrhythmias. However, they can also have harmful or toxic effects, especially when used in excessive amounts or in sensitive populations.

Examples of sodium channel agonists include some drugs used to treat cardiac arrhythmias, such as Class I antiarrhythmic agents like ajmaline, flecainide, and procainamide. These drugs bind to the sodium channels and stabilize their open state, reducing the frequency and velocity of action potentials in the heart. Other substances that can act as sodium channel agonists include certain neurotoxins, such as batrachotoxin and veratridine, which are found in some species of plants and animals and can have potent effects on nerve and muscle function.

'Bufo marinus' is the scientific name for a species of toad commonly known as the Cane Toad or Giant Toad. This toad is native to Central and South America, but has been introduced to various parts of the world including Florida, Australia, and several Pacific islands. The toad produces a toxic secretion from glands on its back and neck, which can be harmful or fatal if ingested by pets or humans.

Apamin is a neurotoxin found in the venom of the honeybee (Apis mellifera). It is a small peptide consisting of 18 amino acids and has a molecular weight of approximately 2000 daltons. Apamin is known to selectively block certain types of calcium-activated potassium channels, which are involved in the regulation of neuronal excitability. It has been used in scientific research to study the role of these ion channels in various physiological processes.

Clinically, apamin has been investigated for its potential therapeutic effects in a variety of neurological disorders, such as epilepsy and Parkinson's disease. However, its use as a therapeutic agent is not yet approved by regulatory agencies due to the lack of sufficient clinical evidence and concerns about its potential toxicity.

Cyclic adenosine monophosphate (cAMP) is a key secondary messenger in many biological processes, including the regulation of metabolism, gene expression, and cellular excitability. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase and is degraded by the enzyme phosphodiesterase.

In the body, cAMP plays a crucial role in mediating the effects of hormones and neurotransmitters on target cells. For example, when a hormone binds to its receptor on the surface of a cell, it can activate a G protein, which in turn activates adenylyl cyclase to produce cAMP. The increased levels of cAMP then activate various effector proteins, such as protein kinases, which go on to regulate various cellular processes.

Overall, the regulation of cAMP levels is critical for maintaining proper cellular function and homeostasis, and abnormalities in cAMP signaling have been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Saxitoxin (STX) is a potent neurotoxin that inhibits the sodium channels in nerve cells, leading to paralysis and potentially death. It is produced by certain species of marine dinoflagellates and cyanobacteria, and can accumulate in shellfish that feed on these organisms. Saxitoxin poisoning, also known as paralytic shellfish poisoning (PSP), is a serious medical condition that can cause symptoms such as numbness, tingling, and paralysis of the mouth and extremities, as well as respiratory failure and death in severe cases. It is important to note that saxitoxin is not used as a therapeutic agent in medicine and is considered a harmful substance.

Biophysical processes refer to the physical mechanisms and phenomena that occur within living organisms and their constituent parts, such as cells, tissues, and organs. These processes are governed by the principles of physics and chemistry and play a critical role in maintaining life and enabling biological functions. Examples of biophysical processes include:

1. Diffusion: The passive movement of molecules from an area of high concentration to an area of low concentration, which enables the exchange of gases, nutrients, and waste products between cells and their environment.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. This process is critical for maintaining cell volume and hydration.
3. Electrochemical gradients: The distribution of ions and charged particles across a membrane, which generates an electrical potential that can drive the movement of molecules and ions across the membrane. This process plays a crucial role in nerve impulse transmission and muscle contraction.
4. Enzyme kinetics: The study of how enzymes catalyze chemical reactions within cells, including the rate of reaction, substrate affinity, and inhibition or activation by other molecules.
5. Cell signaling: The communication between cells through the release and detection of signaling molecules, which can trigger a variety of responses, such as cell division, differentiation, or apoptosis.
6. Mechanical forces: The physical forces exerted by cells and tissues, such as tension, compression, and shear stress, which play a critical role in development, maintenance, and repair of biological structures.
7. Thermodynamics: The study of energy flow and transformation within living systems, including the conversion of chemical energy into mechanical work, heat, or electrical signals.

Understanding biophysical processes is essential for gaining insights into the fundamental mechanisms that underlie life and disease, as well as for developing new diagnostic tools and therapies.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Thermoreceptors are specialized sensory nerve endings or neurons that are sensitive to changes in temperature. They detect and respond to heat or cold stimuli by converting them into electrical signals that are transmitted to the brain for interpretation. These receptors are found throughout the body, particularly in the skin, mucous membranes, and internal organs. There are two main types of thermoreceptors: warm receptors, which respond to increasing temperatures, and cold receptors, which react to decreasing temperatures. The information provided by thermoreceptors helps maintain homeostasis and protect the body from harmful temperature changes.

Glutamic acid is an alpha-amino acid, which is one of the 20 standard amino acids in the genetic code. The systematic name for this amino acid is (2S)-2-Aminopentanedioic acid. Its chemical formula is HO2CCH(NH2)CH2CH2CO2H.

Glutamic acid is a crucial excitatory neurotransmitter in the human brain, and it plays an essential role in learning and memory. It's also involved in the metabolism of sugars and amino acids, the synthesis of proteins, and the removal of waste nitrogen from the body.

Glutamic acid can be found in various foods such as meat, fish, beans, eggs, dairy products, and vegetables. In the human body, glutamic acid can be converted into gamma-aminobutyric acid (GABA), another important neurotransmitter that has a calming effect on the nervous system.

Omega-Conotoxin GVIA is a specific type of conotoxin, a peptide toxin derived from the venom of marine cone snails. This particular variant comes from the Conus geographus species.

Omega-Conotoxins are known for their ability to block N-type voltage-gated calcium channels (VGCCs). In the case of omega-Conotoxin GVIA, it specifically and potently inhibits N-type VGCCs, which play crucial roles in neurotransmitter release and pain signaling. Therefore, it has been extensively studied as a research tool to understand these channels' functions and as a potential lead compound for developing novel therapeutics, particularly for treating chronic pain conditions.

Batrachotoxins are a type of steroidal alkaloid toxin that are found in certain species of frogs, beetles, and plants. They are highly toxic and cause rapid excitation of nerve and muscle tissue leading to paralysis and death. Batrachotoxins work by irreversibly binding to and opening sodium ion channels in cell membranes, causing a persistent depolarization of the membrane potential. This leads to uncontrolled firing of action potentials in nerves and muscles, resulting in the symptoms mentioned above. These toxins are considered among the most potent natural poisons known.

Collecting kidney tubules, also known as collecting ducts, are the final portion of the renal tubule in the nephron of the kidney. They collect filtrate from the distal convoluted tubules and glomeruli and are responsible for the reabsorption of water and electrolytes back into the bloodstream under the influence of antidiuretic hormone (ADH) and aldosterone. The collecting ducts then deliver the remaining filtrate to the ureter, which transports it to the bladder for storage until urination.

Afferent neurons, also known as sensory neurons, are a type of nerve cell that conducts impulses or signals from peripheral receptors towards the central nervous system (CNS), which includes the brain and spinal cord. These neurons are responsible for transmitting sensory information such as touch, temperature, pain, sound, and light to the CNS for processing and interpretation. Afferent neurons have specialized receptor endings that detect changes in the environment and convert them into electrical signals, which are then transmitted to the CNS via synapses with other neurons. Once the signals reach the CNS, they are processed and integrated with other information to produce a response or reaction to the stimulus.

Cytosol refers to the liquid portion of the cytoplasm found within a eukaryotic cell, excluding the organelles and structures suspended in it. It is the site of various metabolic activities and contains a variety of ions, small molecules, and enzymes. The cytosol is where many biochemical reactions take place, including glycolysis, protein synthesis, and the regulation of cellular pH. It is also where some organelles, such as ribosomes and vesicles, are located. In contrast to the cytosol, the term "cytoplasm" refers to the entire contents of a cell, including both the cytosol and the organelles suspended within it.

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

"Cricetulus" is a genus of rodents that includes several species of hamsters. These small, burrowing animals are native to Asia and have a body length of about 8-15 centimeters, with a tail that is usually shorter than the body. They are characterized by their large cheek pouches, which they use to store food. Some common species in this genus include the Chinese hamster (Cricetulus griseus) and the Daurian hamster (Cricetulus dauuricus). These animals are often kept as pets or used in laboratory research.

The hippocampus is a complex, curved formation in the brain that resembles a seahorse (hence its name, from the Greek word "hippos" meaning horse and "kampos" meaning sea monster). It's part of the limbic system and plays crucial roles in the formation of memories, particularly long-term ones.

This region is involved in spatial navigation and cognitive maps, allowing us to recognize locations and remember how to get to them. Additionally, it's one of the first areas affected by Alzheimer's disease, which often results in memory loss as an early symptom.

Anatomically, it consists of two main parts: the Ammon's horn (or cornu ammonis) and the dentate gyrus. These structures are made up of distinct types of neurons that contribute to different aspects of learning and memory.

... cation channels (e.g., TRPC1) and functions as an adaptor protein, tethering signal transduction proteins to TRPC channels. ... "Enkurin is a novel calmodulin and TRPC channel binding protein in sperm". Dev. Biol. 274 (2): 426-35. doi:10.1016/j.ydbio. ... Beech DJ (2007). "Canonical transient receptor potential". Transient Receptor Potential (TRP) Channels. Handbook of ... Enkurin interacts with transient receptor potential canonical (TRPC) ...
... is a family of transient receptor potential cation channels in animals. TRPC channels form the subfamily of channels in ... Many of TRPC channel subunits are able to coassemble. The predominant TRPC channels in the mammalian brain are the TRPC 1,4 and ... TRPC+Cation+Channels at the U.S. National Library of Medicine Medical Subject Headings (MeSH) "Transient Receptor Potential ... TRPC3 and TRPC6 channels are activated by PLC stimulation and diacylglycerol (DAG) production. Both these TRPC channel types ...
... binds TRPC6 (603652) and other transient receptor potential cation channel (TRPC) family members and is involved in ... "Entrez Gene: ring finger protein 24". Lussier MP, Lepage PK, Bousquet SM, Boulay G (May 2008). "RNF24, a new TRPC interacting ... protein, causes the intracellular retention of TRPC". Cell Calcium. 43 (5): 432-43. doi:10.1016/j.ceca.2007.07.009. PMID ...
TRPC) cation channels, TRPC3/6/7. Synthesis of diacylglycerol begins with glycerol-3-phosphate, which is derived primarily from ...
Transient receptor potential cation channel, subfamily C, member 7, also known as TRPC7, is a human gene encoding a protein of ... TRPC Islam, Md. Shahidul (January 2011). Transient Receptor Potential Channels. Advances in Experimental Medicine and Biology. ... Numaga T, Wakamori M, Mori Y (2007). "TRPC7". Transient Receptor Potential (TRP) Channels. Handbook of Experimental ... Nomenclature and structure-function relationships of transient receptor potential channels". Pharmacol. Rev. 57 (4): 427-50. ...
Non-specific cation conductance elicited by the activation of TrkB by BDNF is TRPC3-dependent in the CNS. TRPC channels are ... Zhu MX, Huang J, Du W, Yao H, Wang Y (2011). "TRPC Channels in Neuronal Survival". In Zhu MX (ed.). TRPC Channels in Neuronal ... While it's unclear if TRPC3 channels have equal expression, other members of the TRPC family have been localized to the axon ... Transient receptor potential channel TRPC GRCh38: Ensembl release 89: ENSG00000138741 - Ensembl, May 2017 GRCm38: Ensembl ...
... is subtype of the TRPC family of mammalian transient receptor potential ion channels. TrpC5 is one of the seven mammalian ... "Entrez Gene: transient receptor potential cation channel". Sossey-Alaoui K, Lyon JA, Jones L, Abidi FE, Hartung AJ, Hane B, ... Xu SZ, Zeng B, Daskoulidou N, Chen GL, Atkin SL, Lukhele B (January 2012). "Activation of TRPC cationic channels by mercurial ... Strübing C, Krapivinsky G, Krapivinsky L, Clapham DE (October 2003). "Formation of novel TRPC channels by complex subunit ...
Transient receptor potential cation channel, subfamily C, member 6, also known as TRPC6, is a human gene encoding a protein of ... TRPC6 is a transient receptor potential channel of the classical TRPC subfamily. It has been associated with depression and ... "A mutation in the TRPC6 cation channel causes familial focal segmental glomerulosclerosis". Science. 308 (5729): 1801-4. doi: ... Heiner I, Eisfeld J, Lückhoff A (2004). "Role and regulation of TRP channels in neutrophil granulocytes". Cell Calcium. 33 (5-6 ...
... acting as cation channels. This family is subdivided into 6 subfamilies based on homology: classical (TRPC), vanilloid ... Sodium channels Voltage-gated sodium channels (NaVs) Epithelial sodium channels (ENaCs) Calcium channels (CaVs) Proton channels ... Cation channels of sperm: This small family of channels, normally referred to as Catsper channels, is related to the two-pore ... Plasma membrane channels Examples: Voltage-gated potassium channels (Kv), Sodium channels (Nav), Calcium channels (Cav) and ...
2F37​ Transient receptor potential cation channel subfamily A member 1: PDB: 3J9P​ Voltage-gated ion channel Ion channel ... TRP channels have six TMS helices. These channels can be classified to six groups: TRPV (1-6), TRPM (1-8), TRPC (1-7), TRPA1, ... However, the precise mechanisms leading to TRPC activation remain unclear. TRPC channels regulate nicotine-dependent behavior. ... is a member of the voltage-gated ion channel (VIC) superfamily and consists of cation channels conserved from worms to humans. ...
Transient receptor potential cation channel, subfamily C, member 2, also known as TRPC2, is a protein that in humans is encoded ... TRPC GRCh38: Ensembl release 89: ENSG00000182048 - Ensembl, May 2017 "Human PubMed Reference:". National Center for ... Shahidul (January 2011). Transient Receptor Potential Channels. Advances in Experimental Medicine and Biology. Vol. 704. Berlin ... Nomenclature and structure-function relationships of transient receptor potential channels". Pharmacol. Rev. 57 (4): 427-50. ...
... trpc cation channels MeSH D12.776.157.530.400.901.555 - trpm cation channels MeSH D12.776.157.530.400.901.777 - trpp cation ... trpp cation channels MeSH D12.776.157.530.400.175 - chloride channels MeSH D12.776.157.530.400.175.125 - cystic fibrosis ... channels MeSH D12.776.157.530.400.901.888 - trpv cation channels MeSH D12.776.157.530.450.074 - anion transport proteins MeSH ... shab potassium channels MeSH D12.776.157.530.400.600.900.249 - ether-a-go-go potassium channels MeSH D12.776.157.530.400.600. ...
... trpc cation channels MeSH D12.776.543.585.400.901.555 - trpm cation channels MeSH D12.776.543.585.400.901.777 - trpp cation ... trpp cation channels MeSH D12.776.543.585.400.175 - chloride channels MeSH D12.776.543.585.400.175.125 - cystic fibrosis ... shab potassium channels MeSH D12.776.543.550.425.750.900.249 - ether-a-go-go potassium channels MeSH D12.776.543.550.425.750. ... shab potassium channels MeSH D12.776.543.585.400.750.900.249 - ether-a-go-go potassium channels MeSH D12.776.543.585.400.750. ...
As with most cation channels, TRP channels have negatively charged residues within the pore to attract the positively charged ... the namesake of TRP channels. The phylogeny of TRPC channels has not been resolved in detail, but they are present across ... Transient receptor potential channels (TRP channels) are a group of ion channels located mostly on the plasma membrane of ... Like TRPA1 and other TRP channels, these function as ion channels in a number of sensory systems. TRPA- or TRPA1-like channels ...
... channel) TRPC TRPC1 TRPC2 TRPC3 TRPC4AP TRPC5 TRPC6 TRPC7 TRPM TRPM1 TRPM2 TRPM3 TRPM4 TRPM5 TRPM6 TRPM7 TRPM8 TRPML TRPN TRPP ... Society for Biomechanics Cardiolipin Carlos Chagas Filho Carrier protein CatSper1 CatSper2 CatSper3 CatSper4 Cation channels of ... Voltage-dependent anion channel Voltage-dependent calcium channel Voltage-gated ion channel Voltage-gated potassium channel ... channel alpha 1 Cyclic nucleotide-gated channel alpha 2 Cyclic nucleotide-gated channel alpha 3 Cyclic nucleotide-gated channel ...
... is an ion channel located on the plasma membrane of numerous human and animal cell types. It is a nonspecific cation ... Together with TRPC3 they became the founding members of the TRPC ion channel family. TRPC1 has been shown to interact with: ... Strübing C, Krapivinsky G, Krapivinsky L, Clapham DE (Oct 2003). "Formation of novel TRPC channels by complex subunit ... Rychkov G, Barritt GJ (2007). "TRPC1 Ca2+-Permeable Channels in Animal Cells". TRPC1 Ca(2+)-permeable channels in animal cells ...
... is a family of transient receptor potential cation channels (TRP channels) in animals. All TRPVs are highly calcium ... These are grouped into two broad groups: group 1 includes TRPC ( "C" for canonical), TRPV ("V" for vanilloid), TRPM ("M" for ... TRP channels are a large group of ion channels consisting of six protein families, located mostly on the plasma membrane of ... ISBN 978-94-007-0264-6. Vennekens R, Owsianik G, Nilius B (2008). "Vanilloid transient receptor potential cation channels: an ...
The nonselective cation channel TrpC4 has been shown to be present in high abundance in the cortico-limbic regions of the brain ... Strübing C, Krapivinsky G, Krapivinsky L, Clapham DE (October 2003). "Formation of novel TRPC channels by complex subunit ... This protein forms a non-selective calcium-permeable cation channel that is activated by Gαi-coupled receptors, Gαq-coupled ... "Entrez Gene: transient receptor potential cation channel, subfamily C, member 4". Fowler MA, Sidiropoulou K, Ozkan ED, Phillips ...
TRP channels play a significant role in mechanosensation. There are seven TRP subfamilies: TRPC, TRPM, TRPV, TRPN, TRPA, TRPP, ... It is believed, however, that sensory neurons employ fast, mechanically gated cation channels, and that the depolarization that ... Transient receptor potential channels (TRP channels) (ion channels) introduce the idea that the expression of specific " ... It is believed that rapid, mechanically gated cation channels are characteristic of all sensory neurons. The membrane ...
... +Cation+Channels at the U.S. National Library of Medicine Medical Subject Headings (MeSH) "Transient Receptor Potential ... The TRPM family consists of eight different channels, TRPM1-TRPM8. Unlike the TRPC and TRPV sub-families, TRPM subunits do not ... Nilius B, Owsianik G, Voets T, Peters JA (2007). "Transient receptor potential cation channels in disease" (PDF). Physiol. Rev ... TRPM is a family of transient receptor potential ion channels (M standing for wikt:melastatin). Functional TRPM channels are ...
Gottlieb, P.; Sachs, F. Piezo (2012). "Properties of a cation selective mechanical channel". Channels. 6 (4): 1-6. doi:10.4161/ ... There are seven subfamilies within the TRP superfamily: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin ... Mechanosensitive channels (MSCs), mechanosensitive ion channels or stretch-gated ion channels are membrane proteins capable of ... Mechanosensation Voltage-gated ion channels Ligand-gated ion channels Lipid-gated ion channels Sukharev, S.; Sachs, F. (2012 ...
... there is a short-circuit channel (i.e. a highly K-permeable ion channel) for potassium in the membrane, thus the voltage across ... Skou JC (February 1957). "The influence of some cations on an adenosine triphosphatase from peripheral nerves". Biochimica et ... exchanger and TRPC proteins". Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1802 (12): 1219-29. doi:10.1016 ...
... cation channels (e.g., TRPC1) and functions as an adaptor protein, tethering signal transduction proteins to TRPC channels. ... "Enkurin is a novel calmodulin and TRPC channel binding protein in sperm". Dev. Biol. 274 (2): 426-35. doi:10.1016/j.ydbio. ... Beech DJ (2007). "Canonical transient receptor potential". Transient Receptor Potential (TRP) Channels. Handbook of ... Enkurin interacts with transient receptor potential canonical (TRPC) ...
Ca2+-permeable channel activated by the agonists of Gq-protein-coupled heptahelical receptors. Dysfunctions of TRPC6 are ... resulted in a prolonged intracellular DAG increase and greater Mn2+ influx through the TRPC6 channel. Thus, our data support ... Transient Receptor Potential Canonical (TRPC) proteins form plasma membrane cation channels that are Ca2+-permeable. TRPCs are ... There are seven members in the TRPC subfamily (TRPC1-7). The TRPC6 channel is widely expressed in vascular smooth muscle, where ...
Preventing calcium entry during the repeated PEMF exposure with the co-administration of EGTA or TRP channel antagonists ... Transient receptor potential (TRP) channels appear to mediate these aspects of PEMF stimulation, serving as a conduit for ... Mechanism of inhibition of TRPC cation channels by 2-aminoethoxydiphenylborane. Mol Pharmacol 68, 758-62 (2005). ... The transient receptor potential (TRP) channels are a diverse and widely distributed family of cation channel broadly ...
... cell patch clamp of adult cardiomyocytes to show upregulation of a nonselective cation current reminiscent of TRPC channels ... This TRPC current corresponds to the increased TRPC channel expression noted in hearts of mice subjected to pressure overload. ... OBJECTIVE: Transient receptor potential canonical (TRPC) channels are G protein-coupled receptor operated channels previously ... Our objective of this study is to better understand how TRPC channels influence cardiomyocyte calcium signaling. METHODS AND ...
Ion Channels [D12.776.157.530.400] * Transient Receptor Potential Channels [D12.776.157.530.400.901] * TRPC Cation Channels [ ... Ion Channels [D12.776.543.585.400] * Transient Receptor Potential Channels [D12.776.543.585.400.901] * TRPC Cation Channels [ ... Calcium Channels (1999-2017). TRPC Cation Channels (2006-2017). Public MeSH Note. 2018. History Note. 2018. Date Established. ... TRPC6 Cation Channel Preferred Concept UI. M000625933. Registry Number. 0. Scope Note. A non-selective, calcium permeant TRPC ...
The mammalian TRPC cation channels. Biochim Biophys Acta, 1742(1-3): 21-36. [PubMed] Venkatachalam, K., F. https://sonus- ...
an activator of a subfamily of TRPC (Transient Receptor Potential Canonical) cation channels, TRPC3/6/7. ...
Like (-)-englerin A the effects of tonantzitlolone appear to mediated by activation of cation flux via TRPC ion channels, ... principally the TRPC1/4/5 channel subtypes [1]. Ligand Activity Visualisation Charts. These are box plot that provide a unique ...
TRPC Cation Channels. *Agouti-Related Protein. _. Top Journals Top journals in which articles about this concept have been ...
J:340130 Lin Y, et al., TRPC absence induces pro-inflammatory macrophages and gut microbe disorder, sensitizing mice to colitis ...
To test the concept, we first focused on TRPC5, a member of the transient receptor potential (TRP) calcium channel family, the ... E3 targeting was further applied to voltage-gated sodium channels, leading to discovery of a subtype-specific inhibitor of Na(V ... examples illustrate the potential power of E3 targeting as a systematic method for producing gene-type specific ion-channel ... Here we describe a strategy for generating ion-channel inhibitors. It takes advantage of antibody specificity combined with a ...
We evaluated the heterogeneity of TNBC cell lines for TRPC channel expression and sensitivity to cation-disrupting drugs. ... TRPC) channels of the 1, 4 and 5 type (TRPC1/4/5 channels). EXPERIMENTAL APPROACH: The effects of TZL on renal cell carcinoma ... these data reveal TRPC1/4 channels as potential biomarkers of TNBC cell lines with dysfunctional mechanisms of cation ... Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias ...
We have also shown that FRTL-5 cells express only the TRPC2 channel of the TRPC family of cation channels. In the present ... the TRPC2 channel. Our data thus point to a novel mechanism by which the TRPC2 channels can be regulated. ... Phosphatase Inhibitor Calyculin A Activates TRPC2 Channels in Thyroid FRTL-5 Cells ...
... and additionally involves activation of nonselective cation channels TRPC. ...
We investigated the contribution of excitatory transient receptor potential canonical (TRPC) cation channels to posttraumatic ... abstract = "We investigated the contribution of excitatory transient receptor potential canonical (TRPC) cation channels to ... N2 - We investigated the contribution of excitatory transient receptor potential canonical (TRPC) cation channels to ... AB - We investigated the contribution of excitatory transient receptor potential canonical (TRPC) cation channels to ...
... with a specific focus on the pharmacology of TRPC cation channels.. Twitter handle: @RSBon_Lab. ... Understanding potent small-molecule modulation of TRPC1/4/5 channels. - Prof. Mélanie Ethève-Quelquejeu, Paris Descartes ...
... the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel ... We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone ... TRPC Cation Channels, Vestibule, Labyrinth ... also show that expression of the TRPC3 cation calcium channel, ... Animals, Behavior, Animal, Brain-Derived Neurotrophic Factor, Cochlea, Hair Cells, Vestibular, KCNQ Potassium Channels, Mice, ...
transient receptor potential canonical (TRPC) proteins form Ca (2 +) - permeable cation channel activated on stimulation of ... Screening of Transient Receptor Potential Canonical Channel Activators Identifies Novel Neurotrophic Piperazine Compounds.. by ... Screening of Transient Receptor Potential Canonical Channel Activators Identifies Novel Neurotrophic Piperazine Compounds. ... Screening of Transient Receptor Potential Canonical Channel Activators Identifies Novel Neurotrophic Piperazine Compounds. ...
We investigated whether expression of non-selective cation channels of the transient receptor potential canonical (TRPC) ... channel family are associated with proinflammatory cytokines in monocytes ... channel transcripts with proinflammatory cytokines.在哪里下载?这篇文献在哪里可以阅读?: ... We investigated whether expression of non-selective cation channels of the transient receptor potential canonical (TRPC
... indicating BTP2 did not block divalent cation entry by depolarization induced by activating monovalent cation entry channels. ... indicating BTP2 did not block divalent cation entry by depolarization induced by activating monovalent cation entry channels. ... indicating BTP2 did not block divalent cation entry by depolarization induced by activating monovalent cation entry channels. ... indicating BTP2 did not block divalent cation entry by depolarization induced by activating monovalent cation entry channels. ...
TRP channels are expressed in a large variety of cells and tissues, and by increasing cation intracellular concentration, they ... Some members of the TRP superfamily, namely vanilloid (TRPV), canonical (TRPC), melastatin (TRPM), and ankyrin (TRPA), have ... Ion channels play a crucial role in a wide range of biological processes, including cell cycle regulation and cancer ... Ion channels play a crucial role in a wide range of biological processes, including cell cycle regulation and cancer ...
TRPA1 Cation Channel [D12.776.157.530.400.901.250] * TRPC Cation Channels [D12.776.157.530.400.901.500] ... TRPV Cation Channels Preferred Concept UI. M0194000. Registry Number. 0. Scope Note. A subgroup of TRP cation channels named ... TRPV Cation Channels Preferred Term Term UI T626131. Date12/27/2004. LexicalTag NON. ThesaurusID NLM (2006). ... A subgroup of TRP cation channels named after the vanilloid receptor. They are very sensitive to TEMPERATURE; hot spicy food, ...
A group of channels participating in these processes is the transient receptor potential (TRP) family of cation channels. These ... One of these subfamilies is the transient receptor potential canonical (TRPC) family of channels. This ion channel family ... In this review, we will describe the importance of the TRPC channels and their interacting molecular partners in the etiology ... Transient Receptor Potential Canonical (TRPC) Channels as Modulators of Migration and Invasion. Asghar. 1 ...
Effect of TRP channel blockade on apoptosis induced by lysoPC. There are six tissue specific isoforms of TRPC channels in ... Vriens J, Appendino G and Nilius B. Pharmacology of vanilloid transient receptor potential cation channels. Mol Pharmacol. 2009 ... vehicle control). These results indicate that TRPC channels, but not TRPV2 or TRPV4 channels, are involved in lysoPC-induced Ca ... The general TRPC channel blocker SKF-96365 [23], the specific TRPC3 blocker Pyr3 [24], the TRPV2 channel blocker ruthenium red ...
The TRPC6 channel, a member of the Transient receptor potential (TRP) family, which is a non-selective cation-permeable channel ... The present invention relates generally to Transient Receptor Potential Canonical (TRPC) Channel proteins, and more ... In yet other embodiments, methods of treating a disorder or a disease in a subject mediated by TRPC protein activity are ... The invention also provides another therapeutic agent for use in a method of treating a disease or condition mediated by TRPC ...
2011. Transient receptor potential cation channel, subfamily C, member 5 (TRPC5) is a cold-transducer in the peripheral nervous ... 2012. Selective Gαi subunits as novel direct activators of transient receptor potential canonical (TRPC)4 and TRPC5 channels.. ... 2010. Rat hypocretin/orexin neurons are maintained in a depolarized state by TRPC channels.. PLoS One, e15673. ... 2011. Guinea pig kisspeptin neurons are depolarized by leptin via activation of TRPC channels.. Endocrinology, 1503-1514. ...
Simulations showed that fine-tuning of pre- and post-synaptic parameters generated effective MF-GrC transmission channels, ... was predicted by parameter optimization in detailed computational models based on available knowledge on GrC ionic channels. ... Petersen, O. H. Cation channels: homing in on the elusive CAN channels. Curr. Biol. 12, R520-522 (2002). ... TRPC; e.g., see ref. 18) could also contribute. Future experiments may exploit knockout mice to dissect the contribution, if ...
Moreover, ruthenium red (a general TRP channel blocker), BTP2 (a general TRPC channel inhibitor), and pyrazole-3 (a selective ... In whole-cell recordings, IgG-IC induced a nonselective cation current (I IC) in the rat DRG neurons, carried by Ca 2+ and Na + ... Moreover, ruthenium red (a general TRP channel blocker), BTP2 (a general TRPC channel inhibitor), and pyrazole-3 (a selective ... Moreover, ruthenium red (a general TRP channel blocker), BTP2 (a general TRPC channel inhibitor), and pyrazole-3 (a selective ...
In mammals, TRP channels comprise six related protein families (TRPC, TRPV,TRPM,TRPA,TRPML,TRPP). In genera1, TRP channels are ... TRPV4, a member of TRPV subfamily, is a nonselective cation channel that is activated by hypotonic stimulus, warm temperatures ... In mammals, TRP channels comprise six related protein families (TRPC, TRPV,TRPM,TRPA,TRPML,TRPP). In genera1, TRP channels are ... TRPV4, a member of TRPV subfamily, is a nonselective cation channel that is activated by hypotonic stimulus, warm temperatures ...
TRPC3 channels are cation channels mediating transplasmamembrane calcium influx [ten]. Before reports from our team and other ... We noticed that the two the inhibition of TRPC channels utilizing 2-APB and down-regulation of TRPC3 by particular siRNA ... Experimental knowledge from a number of teams indicated two-APB blocks TRPC channels [seventeen,18,19]. We calculated ... indicating that activation of non-selective cation channels may be necessary for migration of LPC-stimulated monocytes [27]. 2- ...
  • Enkurin interacts with transient receptor potential canonical (TRPC) cation channels (e.g. (wikipedia.org)
  • Transient receptor potential canonical 6 (TRPC6) is a cation selective, DAG-regulated, Ca 2+ -permeable channel activated by the agonists of G q -protein-coupled heptahelical receptors. (mdpi.com)
  • OBJECTIVE: Transient receptor potential canonical (TRPC) channels are G protein-coupled receptor operated channels previously implicated in cardiac hypertrophy. (duke.edu)
  • We investigated the contribution of excitatory transient receptor potential canonical (TRPC) cation channels to posttraumatic hyperexcitability in the brain 7 days following controlled cortical impact model of traumatic brain injury (TBI) to the parietal cortex in male adult mice. (uthscsa.edu)
  • Screening of Transient Receptor Potential Canonical Channel Activators Identifies Novel Neurotrophic Piperazine Compounds. (nt-4.com)
  • transient receptor potential canonical (TRPC) proteins form Ca (2 +) - permeable cation channel activated on stimulation of metabotropic receptors coupled to phospholipase C. Among. (nt-4.com)
  • We investigated whether expression of non-selective cation channels of the transient receptor potential canonical (TRPC) channel family are associated with proinflammatory cytokines in monocytes. (shengsci.com)
  • We compared its action on SOC activation in a number of cell types and evaluated its modification of three specific TRP channels, canonical transient receptor potential 3 (TRPC3), TRPC5, and TRPV6, to throw light on any link between SOC and TRP channel function. (psu.edu)
  • The present invention relates generally to Transient Receptor Potential Canonical (TRPC) Channel proteins, and more particularly to inhibitors of Transient Receptor Potential Channel 6 (TRPC6) protein activity, pharmaceutical compositions comprising said inhibitors and to methods of using such inhibitors. (justia.com)
  • an activator of a subfamily of TRPC ( T ransient R eceptor P otential C anonical) cation channels, TRPC3/6/7. (wikidoc.org)
  • We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF), is altered in these animals. (ox.ac.uk)
  • Importantly, direct activation of TRPC3 channels by diacylglycerol was also blocked by BTP2 (IC 50 ∼ 0.3 μM). (psu.edu)
  • BTP2 still blocked TRPC3 in medium with N-methyl-D-glucamine-chloride replacing Na + , indicating BTP2 did not block divalent cation entry by depolarization induced by activating monovalent cation entry channels. (psu.edu)
  • Whereas whole-cell carbachol-induced TRPC3 current was blocked by 3 μM BTP2, single TRPC3 channel recordings revealed persistent short openings suggesting BTP2 reduces the open probability of the channel rather than its pore properties. (psu.edu)
  • TRPC5 channels transiently expressed in HEK293 cells were blocked by BTP2 in the same range as TRPC3. (psu.edu)
  • These results demonstrate the novel information that TRPC1/TRPC3 channels mediate lysoPC-induced Ca 2+ influx and apoptosis via activating the pro-apoptotic proteins Bax and cleaved caspase-3 and inhibiting the anti-apoptotic protein Bcl-2 and the survival kinase pAkt in human coronary artery SMCs, which implies that TRPC1/TRC3 channels may be the therapeutic target of lysoPC-induced disorders such as atherosclerosis. (oncotarget.com)
  • Moreover, ruthenium red (a general TRP channel blocker), BTP2 (a general TRPC channel inhibitor), and pyrazole-3 (a selective TRPC3 blocker) each potently inhibited the I IC . (johnshopkins.edu)
  • These results indicated that the activation of neuronal FcγRI triggers TRPC channels through the Syk-PLC-IP 3 pathway and that TRPC3 is a key molecular target for the excitatory effect of IgG-IC on DRG neurons. (johnshopkins.edu)
  • TRPC Channel Remodeling in a Mouse of Essential Hypertension: The TRPC3-TRPC6 Game of Thrones. (uva.es)
  • METHODS AND RESULTS: Here, we used whole cell patch clamp of adult cardiomyocytes to show upregulation of a nonselective cation current reminiscent of TRPC channels subjected to pressure overload. (duke.edu)
  • TRPC1) and functions as an adaptor protein, tethering signal transduction proteins to TRPC channels. (wikipedia.org)
  • Scholars@Duke publication: TRPC1 channels are critical for hypertrophic signaling in the heart. (duke.edu)
  • Importantly, we show that mice lacking TRPC1 channels are missing this putative TRPC current. (duke.edu)
  • CONCLUSIONS: From these studies, we suggest that TRPC1 channels are critical for the adaptation to biomechanical stress and TRPC dysregulation leads to maladaptive cardiac hypertrophy and failure. (duke.edu)
  • We investigated if TRPC1/TRPC4/TRPC5 channel expression is upregulated in excitatory neurons after TBI in contribution to epileptogenic hyperexcitability in key hippocampal and cortical circuits that have substantial cholinergic innervation. (uthscsa.edu)
  • Conclusion:We have defined a novel physiological role for the TRPC1 channel. (scite.ai)
  • The present invention provides compounds which inhibit TRPC proteins, and more specifically inhibit TRPC6 proteins. (justia.com)
  • To date, TrpC5 functions in partnership with up to 60 proteins, including other TrpC members, IP3 receptors, NCS-1 and caveolin. (phosphosolutions.com)
  • In genera1, TRP channels are ubiquitously expressed, indicating that most ce11s have a number of TRP channel proteins. (soken.ac.jp)
  • All these events are primarily regulated by an array of regulatory proteins that are present on the cell surface, such as ion channels, receptors and adhesion molecules which sense the different chemical signaling cues and allow the neurons to respond accordingly [ 8-10 ]. (silverchair.com)
  • The TRPC6 channel, a member of the Transient receptor potential (TRP) family, which is a non-selective cation-permeable channel, is activated by diacylglycerol and the like produced by activation of phospholipase C and exerts physiological and pathophysiological effects. (justia.com)
  • Antagonistic regulation of actin dynamics and cell motility by TRPC5 and TRPC6 channels. (phosphosolutions.com)
  • We found that PAR1 activation increases [Ca 2+ ] i via TRPC6 channels. (figshare.com)
  • A non-selective, calcium permeant TRPC cation channel that contains four ANKYRIN REPEATS and is activated by DIACYLGLYCEROL independently of PROTEIN KINASE C . It is expressed in placenta, lung, spleen, ovary and the small intestine, as well as by PODOCYTES in the kidney glomerulus. (nih.gov)
  • Transient receptor potential ankyrin 1 (TRPA1) channel is a type of nonselective transmembrane cation channel with multiple ankyrin repeats on its N-terminal [ 17 - 20 ]. (biomedcentral.com)
  • Transient Receptor Potential (TRP) Channels. (wikipedia.org)
  • Transient receptor potential (TRP) channels appear to mediate these aspects of PEMF stimulation, serving as a conduit for extracellular calcium. (nature.com)
  • G protein-coupled receptor signaling is known to govern the hypertrophic response through the regulation of ion channel activity and downstream signaling in failing cardiomyocytes. (duke.edu)
  • To test the concept, we first focused on TRPC5, a member of the transient receptor potential (TRP) calcium channel family, the study of which has been hindered by poor pharmacological tools. (ox.ac.uk)
  • The underlying mechanism includes acutely decreased acetylcholinesterase function, resulting in greater G q / 11 -coupled muscarinic receptor activation of TRPC channels. (uthscsa.edu)
  • The coupling between receptor-mediated Ca 2+ store release and the activation of "store-operated" Ca 2+ entry channels is an important but so far poorly understood mechanism. (psu.edu)
  • The transient receptor potential (TMP) superfamily of channels contains several members that may serve the function of store-operated channels (SOCs). (psu.edu)
  • A subgroup of TRP cation channels named after the vanilloid receptor. (nih.gov)
  • The participation of transient receptor potential (TRP) channels was proposed in these reports. (oncotarget.com)
  • Short transient receptor potential channel 5 or TrpC5 is encoded by the gene TRPC5. (phosphosolutions.com)
  • TrpC5 belongs to the transient receptor family, a group of membrane bound ion channels that have a relatively non-selective permeability to cations, including sodium, calcium and magnesium. (phosphosolutions.com)
  • u003cbr /\u003eThe capsaicin receptor TRPV1 is a nonselective cation channel expressed in sensory neurons and activated by various noxious stimuli. (soken.ac.jp)
  • In this work, we explored the role of transient receptor potential vanilloid 2 (TRPV2), a non-selective cation channel in the context of neurite functions. (silverchair.com)
  • Transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in pain and inflammation. (biomedcentral.com)
  • In selectivity assays englerin A weakly inhibits TRPA1, TRPV3/V4, and TRPM8 which suggests that englerin A may bind a common feature of TRP ion channels. (epfl.ch)
  • The cation channel TRPA1 transduces a myriad of noxious chemical stimuli into nociceptor electrical excitation and neuropeptide release, leading to pain and neurogenic inflammation. (elifesciences.org)
  • Despite emergent evidence that TRPA1 is regulated by the membrane environment, it remains unknown whether this channel localizes in membrane microdomains or whether it interacts with cholesterol. (elifesciences.org)
  • Using total internal reflection fluorescence microscopy and density gradient centrifugation we found that mouse TRPA1 localizes preferably into cholesterol-rich domains and functional experiments revealed that cholesterol depletion decreases channel sensitivity to chemical agonists. (elifesciences.org)
  • We discuss the impact of such interactions on TRPA1 gating mechanisms, regulation by the lipid environment, and role of this channel in sensory membrane microdomains, all of which helps to understand the puzzling pharmacology and pathophysiology of this channel. (elifesciences.org)
  • However, little is known about the significance of the TRPA1 channel in the pathophysiology of Alzheimer's disease (AD). (biomedcentral.com)
  • The protein expression of TRPA1 channels was higher in brains, mainly astrocytes of the hippocampus, from APP/PS1 Tg mice than WT mice. (biomedcentral.com)
  • Ablation of TRPA1-channel function in APP/PS1 Tg mice alleviated behavioral dysfunction, Aβ plaque deposition and pro-inflammatory cytokine production but increased astrogliosis in brain lesions. (biomedcentral.com)
  • these were abrogated by pharmacological inhibition of TRPA1 channel activity, disruption of TRPA1 channel function or removal of extracellular Ca 2+ . (biomedcentral.com)
  • Inhibition of TRPA1 channel activity exacerbated Aβ 1-42 -induced astrogliosis but inhibited Aβ 1-42 -increased PP2B activation, the production of pro-inflammatory cytokines and activities of transcriptional factors NF-κB and NFAT in astrocytes and in APP/PS1 Tg mice. (biomedcentral.com)
  • Upon detection of these signals, the TRPA1 channel is activated, which results in increased intracellular Ca 2+ levels and activated downstream signaling cascades [ 17 - 20 ]. (biomedcentral.com)
  • His research group uses chemical, biochemical and biophysical approaches to unravel molecular mechanisms of health/disease and the effects of bioactive small molecules, with a specific focus on the pharmacology of TRPC cation channels. (gp2a.org)
  • Sphingosine 1-phosphate (S1P) receptors and human ether-a 0 -go-go-related gene (HERG (KCNH2)) potassium channels are important modulators of cell migration. (scite.ai)
  • Elevation of serine proteases may mediate [Ca 2+ ] i dynamics in podocytes through the protease-activated receptors (PARs) pathway, including associated activation of non-specific cation channels. (figshare.com)
  • Blockade of TRPC4/TRPC5 channels with M084 reduced neuronal hyperexcitation and impeded epileptogenic progression of kindling. (uthscsa.edu)
  • Contribution of zinc-dependent delayed calcium influx via TRPC5 in oxidative neuronal death and its prevention by novel TRPC antagonist. (phosphosolutions.com)
  • TRPV4, a member of TRPV subfamily, is a nonselective cation channel that is activated by hypotonic stimulus, warm temperatures (~25-34℃) or chemica1 compounds such as 4α-PDD, and is expressed in various tissues. (soken.ac.jp)
  • TRPC4/5 ion channel experiments with five compounds showed delayed or reduced agonism with TRPC5, at much higher concentrations than englerin A. With TRPC4, these compounds all had no effect at 10 µM. (bvsalud.org)
  • We observed that the time-dependent upregulation of TRPC4/TRPC5-containing channels alters cholinergic responses and activity of principal neurons acting to increase proexcitatory sensitivity. (uthscsa.edu)
  • Hypoosmotic- and pressure-induced membrane stretch activate TRPC5 channels. (phosphosolutions.com)
  • Background:The identity of calcium channels in the thyroid is undefined. (scite.ai)
  • The results indicate a strong functional link between the operation of expressed TRPC channels and endogenous SOC activity. (psu.edu)
  • Overall, our evidence suggests that TBI-induced plasticity of TRPC channels strongly contributes to overt hyperexcitability and primes the hippocampus and cortex for seizures. (uthscsa.edu)
  • Guinea pig kisspeptin neurons are depolarized by leptin via activation of TRPC channels. (phosphosolutions.com)
  • However, function of the highly Ca 2+ -selective TRPV6 channel, with many channel properties akin to SOCs, was entirely unaffected by BTP2. (psu.edu)
  • These examples illustrate the potential power of E3 targeting as a systematic method for producing gene-type specific ion-channel inhibitors for use in routine assays on cells or tissues from a range of species and having therapeutic potential. (ox.ac.uk)
  • the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. (ox.ac.uk)
  • E3 targeting was further applied to voltage-gated sodium channels, leading to discovery of a subtype-specific inhibitor of Na(V)1.5. (ox.ac.uk)
  • This calcium increase is mediated through a G q /G 11 phospholipase C IP 3 pathway, and additionally involves activation of nonselective cation channels TRPC. (pbkom.eu)
  • This TRPC current corresponds to the increased TRPC channel expression noted in hearts of mice subjected to pressure overload. (duke.edu)
  • It was already known that GrC of vestibulo-cerebellum are specialized to slow-down firing modulation based on the expression of low-threshold Ca 2+ channels 27 . (nature.com)
  • Therefore, despite their morphological homogeneity, GrCs have differentiated conductance tuning and ionic channel expression, which could be further modified by fine variants in dendritic/axonal organization 28 . (nature.com)
  • Expression of the TRPC4 cation channel was the cell line feature that best correlated with sensitivity to englerin A, suggesting the hypothesis that TRPC4 is the efficacy target for englerin A. Genetic experiments demonstrate that TRPC4 expression is both necessary and sufficient for englerin A induced growth inhibition. (epfl.ch)
  • Ca 2+ is a well-known second messenger that regulates a wide range of cell functions including excitation-contraction coupling, excitation-secretion coupling, gene transcription, cell growth, differentiation, apoptosis, membrane fusion, and ion channel activation [ 8 - 11 ]. (oncotarget.com)
  • These experiments confirm that activation of TRPC4/C5 channels inhibits tumor cell line proliferation and confirms the TRPC4 target hypothesis generated by the cell line profiling. (epfl.ch)
  • Englerin A Agonizes the TRPC4/C5 Cation Channels to Inhibit Tumor Cell Line Proliferation. (epfl.ch)
  • In vivo experiments show that englerin A is lethal in rodents near doses needed to activate the TRPC4 channel. (epfl.ch)
  • Indeed, changes in the spatiotemporal Ca 2+ -levels and Ca 2+ -oscillation patterns have been correlated with most of these functions [ 2 , 8-10 ], which strongly suggest the importance of different Ca 2+ channels in the regulation of neuritogenesis. (silverchair.com)
  • Generation of functional ion-channel tools by E3 targeting. (ox.ac.uk)
  • The purpose of this study was to investigate the signaling pathways and transduction channels activated downstream of IgG-IC and FcγRI. (johnshopkins.edu)
  • Preventing calcium entry during the repeated PEMF exposure with the co-administration of EGTA or TRP channel antagonists precluded the inhibition of differentiation. (nature.com)
  • Teresa Perez-Garcia, M. Oxygen-Sensitive Potassium Channels in Chemoreceptor Cell Physiology Making a Virtue of Necessity . (uva.es)
  • It takes advantage of antibody specificity combined with a pattern recognition approach that targets the third extracellular region (E3) of a channel. (ox.ac.uk)
  • pathological vitamin are less almost added than their inner basophils, and are proteolytically classified as neonatal activated on their adhesion of beginning by MAPKK site channels. (evakoch.com)