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.
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.
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.
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.
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.
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.
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.
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 selectively inhibited by a variety of SCORPION VENOMS.
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.
A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.
Potassium channels whose activation is dependent on intracellular calcium concentrations.
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 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 shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.
A voltage-gated potassium channel that is expressed primarily in the HEART.
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 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 fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.
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.
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.
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.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
Potassium channels that contain two pores in tandem. They are responsible for baseline or leak currents and may be the most numerous of all K channels.
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 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 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).
A class of drugs that act by selective inhibition of calcium influx through cellular membranes.
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.
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.
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.
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.
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.
Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.
An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.
A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)
The ability of a substrate to allow the passage of ELECTRONS.
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).
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.
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.
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 aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
One of the POTASSIUM CHANNEL BLOCKERS, with secondary effect on calcium currents, which is used mainly as a research tool and to characterize channel subtypes.
The pore-forming subunits of large-conductance calcium-activated potassium channels. They form tetramers in CELL MEMBRANES.
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.
A potassium-channel opening vasodilator that has been investigated in the management of hypertension. It has also been tried in patients with asthma. (Martindale, The Extra Pharmacopoeia, 30th ed, p352)
A guanidine that opens POTASSIUM CHANNELS producing direct peripheral vasodilatation of the ARTERIOLES. It reduces BLOOD PRESSURE and peripheral resistance and produces fluid retention. (Martindale The Extra Pharmacopoeia, 31st ed)
A 37-amino acid residue peptide isolated from the scorpion Leiurus quinquestriatus hebraeus. It is a neurotoxin that inhibits calcium activated potassium channels.
Potassium or potassium compounds used in foods or as foods.
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.
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.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
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.
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.
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.
CALCIUM CHANNELS that are concentrated in neural tissue. Omega toxins inhibit the actions of these channels by altering their voltage dependence.
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.
Inorganic compounds that contain barium as an integral part of the molecule.
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.
A condition due to decreased dietary intake of potassium, as in starvation or failure to administer in intravenous solutions, or to gastrointestinal loss in diarrhea, chronic laxative abuse, vomiting, gastric suction, or bowel diversion. Severe potassium deficiency may produce muscular weakness and lead to paralysis and respiratory failure. Muscular malfunction may result in hypoventilation, paralytic ileus, hypotension, muscle twitches, tetany, and rhabomyolysis. Nephropathy from potassium deficit impairs the concentrating mechanism, producing POLYURIA and decreased maximal urinary concentrating ability with secondary POLYDIPSIA. (Merck Manual, 16th ed)
The rate dynamics in chemical or physical systems.
Inorganic compounds that contain potassium as an integral part of the molecule.
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.
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 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.
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.
Compounds with a core of fused benzo-pyran rings.
A highly neurotoxic polypeptide from the venom of the honey bee (Apis mellifera). It consists of 18 amino acids with two disulfide bridges and causes hyperexcitability resulting in convulsions and respiratory paralysis.
The regulatory subunits of large-conductance calcium-activated potassium channels.
The relationship between the dose of an administered drug and the response of the organism to the drug.
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.
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.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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 derivative of the NIACINAMIDE that is structurally combined with an organic nitrate. It is a potassium-channel opener that causes vasodilatation of arterioles and large coronary arteries. Its nitrate-like properties produce venous vasodilation through stimulation of guanylate cyclase.
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 white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
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.
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.
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.
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.
A benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group.
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.
Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.
Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.
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 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.
10-carbon saturated monocarboxylic acids.
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.
Organic compounds containing both the hydroxyl and carboxyl radicals.
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.
Established cell cultures that have the potential to propagate indefinitely.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A delayed rectifier subtype of shaker potassium channels that has been described in NEURONS and ASTROCYTES.
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.
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.
Unstable isotopes of potassium that decay or disintegrate emitting radiation. K atoms with atomic weights 37, 38, 40, and 42-45 are radioactive potassium isotopes.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
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 family of neuronal calcium-sensor proteins that interact with and regulate potassium channels, type A.
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.
Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
An actinomycete used for production of commercial ANTIBIOTICS and as a host for gene cloning.
A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.
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.
Elements of limited time intervals, contributing to particular results or situations.
Drugs used to cause dilation of the blood vessels.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
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 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.
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)
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
Pyridines substituted in any position with an amino group. May be hydrogenated, but must retain at least one double bond.
Use of electric potential or currents to elicit biological responses.
CALCIUM CHANNELS located within the PURKINJE CELLS of the cerebellum. They are involved in stimulation-secretion coupling of neurons.
A group of compounds that are monomethyl derivatives of pyridines. (From Dorland, 28th ed)
A potent direct-acting peripheral vasodilator (VASODILATOR AGENTS) that reduces peripheral resistance and produces a fall in BLOOD PRESSURE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p371)
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).
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.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
A superorder of CEPHALOPODS comprised of squid, cuttlefish, and their relatives. Their distinguishing feature is the modification of their fourth pair of arms into tentacles, resulting in 10 limbs.
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.
Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.
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.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
Abnormally low potassium concentration in the blood. It may result from potassium loss by renal secretion or by the gastrointestinal route, as by vomiting or diarrhea. It may be manifested clinically by neuromuscular disorders ranging from weakness to paralysis, by electrocardiographic abnormalities (depression of the T wave and elevation of the U wave), by renal disease, and by gastrointestinal disorders. (Dorland, 27th ed)
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.
An inorganic compound that is used as a source of iodine in thyrotoxic crisis and in the preparation of thyrotoxic patients for thyroidectomy. (From Dorland, 27th ed)
A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.
The hollow, muscular organ that maintains the circulation of the blood.
The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
Synthetic transcripts of a specific DNA molecule or fragment, made by an in vitro transcription system. This cRNA can be labeled with radioactive uracil and then used as a probe. (King & Stansfield, A Dictionary of Genetics, 4th ed)
An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
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.
CALCIUM CHANNELS located in the neurons of the brain.
Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.
A sulphonylurea hypoglycemic agent with actions and uses similar to those of CHLORPROPAMIDE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)
Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ENZYMES. They include palytoxin, sarcophine, and anthopleurine.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
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.
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.
Proteins prepared by recombinant DNA technology.
The nonstriated involuntary muscle tissue of blood vessels.
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 potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.
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.
A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.
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.
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.
The physical characteristics and processes of biological systems.
Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.
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 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.
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 powder that dissolves in water, which is administered orally, and is used as a diuretic, expectorant, systemic alkalizer, and electrolyte replenisher.
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 regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
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.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
CALCIUM CHANNELS located in the neurons of the brain. They are inhibited by the marine snail toxin, omega conotoxin MVIIC.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
A rare neuromuscular disorder with onset usually in late childhood or early adulthood, characterized by intermittent or continuous widespread involuntary muscle contractions; FASCICULATION; hyporeflexia; MUSCLE CRAMP; MUSCLE WEAKNESS; HYPERHIDROSIS; TACHYCARDIA; and MYOKYMIA. Involvement of pharyngeal or laryngeal muscles may interfere with speech and breathing. The continuous motor activity persists during sleep and general anesthesia (distinguishing this condition from STIFF-PERSON SYNDROME). Familial and acquired (primarily autoimmune) forms have been reported. (From Ann NY Acad Sci 1998 May 13;841:482-496; Adams et al., Principles of Neurology, 6th ed, p1491)
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
Abnormally high potassium concentration in the blood, most often due to defective renal excretion. It is characterized clinically by electrocardiographic abnormalities (elevated T waves and depressed P waves, and eventually by atrial asystole). In severe cases, weakness and flaccid paralysis may occur. (Dorland, 27th ed)
Toxic substances from microorganisms, plants or animals that interfere with the functions of the nervous system. Most venoms contain neurotoxic substances. Myotoxins are included in this concept.
A paraneoplastic syndrome marked by degeneration of neurons in the LIMBIC SYSTEM. Clinical features include HALLUCINATIONS, loss of EPISODIC MEMORY; ANOSMIA; AGEUSIA; TEMPORAL LOBE EPILEPSY; DEMENTIA; and affective disturbance (depression). Circulating anti-neuronal antibodies (e.g., anti-Hu; anti-Yo; anti-Ri; and anti-Ma2) and small cell lung carcinomas or testicular carcinoma are frequently associated with this syndrome.
Pyridine moieties which are partially saturated by the addition of two hydrogen atoms in any position.
The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.
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.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
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)
Permanganic acid (HMnO4), potassium salt. A highly oxidative, water-soluble compound with purple crystals, and a sweet taste. (From McGraw-Hill Dictionary of Scientific and Technical Information, 4th ed)
A variety of neuromuscular conditions resulting from MUTATIONS in ION CHANNELS manifesting as episodes of EPILEPSY; HEADACHE DISORDERS; and DYSKINESIAS.
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.
A condition marked by recurrent seizures that occur during the first 4-6 weeks of life despite an otherwise benign neonatal course. Autosomal dominant familial and sporadic forms have been identified. Seizures generally consist of brief episodes of tonic posturing and other movements, apnea, eye deviations, and blood pressure fluctuations. These tend to remit after the 6th week of life. The risk of developing epilepsy at an older age is moderately increased in the familial form of this disorder. (Neurologia 1996 Feb;11(2):51-5)
A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Azoles of one NITROGEN and two double bonds that have aromatic chemical properties.
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 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.
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 electrical properties, characteristics of living organisms, and the processes of organisms or their parts that are involved in generating and responding to electrical charges.

Leptin suppression of insulin secretion and gene expression in human pancreatic islets: implications for the development of adipogenic diabetes mellitus. (1/9961)

Previously we demonstrated the expression of the long form of the leptin receptor in rodent pancreatic beta-cells and an inhibition of insulin secretion by leptin via activation of ATP-sensitive potassium channels. Here we examine pancreatic islets isolated from pancreata of human donors for their responses to leptin. The presence of leptin receptors on islet beta-cells was demonstrated by double fluorescence confocal microscopy after binding of a fluorescent derivative of human leptin (Cy3-leptin). Leptin (6.25 nM) suppressed insulin secretion of normal islets by 20% at 5.6 mM glucose. Intracellular calcium responses to 16.7 mM glucose were rapidly reduced by leptin. Proinsulin messenger ribonucleic acid expression in islets was inhibited by leptin at 11.1 mM, but not at 5.6 mM glucose. Leptin also reduced proinsulin messenger ribonucleic acid levels that were increased in islets by treatment with 10 nM glucagon-like peptide-1 in the presence of either 5.6 or 11.1 mM glucose. These findings demonstrate direct suppressive effects of leptin on insulin-producing beta-cells in human islets at the levels of both stimulus-secretion coupling and gene expression. The findings also further indicate the existence of an adipoinsular axis in humans in which insulin stimulates leptin production in adipocytes and leptin inhibits the production of insulin in beta-cells. We suggest that dysregulation of the adipoinsular axis in obese individuals due to defective leptin reception by beta-cells may result in chronic hyperinsulinemia and may contribute to the pathogenesis of adipogenic diabetes.  (+info)

Alternative sulfonylurea receptor expression defines metabolic sensitivity of K-ATP channels in dopaminergic midbrain neurons. (2/9961)

ATP-sensitive potassium (K-ATP) channels couple the metabolic state to cellular excitability in various tissues. Several isoforms of the K-ATP channel subunits, the sulfonylurea receptor (SUR) and inwardly rectifying K channel (Kir6.X), have been cloned, but the molecular composition and functional diversity of native neuronal K-ATP channels remain unresolved. We combined functional analysis of K-ATP channels with expression profiling of K-ATP subunits at the level of single substantia nigra (SN) neurons in mouse brain slices using an RT-multiplex PCR protocol. In contrast to GABAergic neurons, single dopaminergic SN neurons displayed alternative co-expression of either SUR1, SUR2B or both SUR isoforms with Kir6.2. Dopaminergic SN neurons expressed alternative K-ATP channel species distinguished by significant differences in sulfonylurea affinity and metabolic sensitivity. In single dopaminergic SN neurons, co-expression of SUR1 + Kir6.2, but not of SUR2B + Kir6.2, correlated with functional K-ATP channels highly sensitive to metabolic inhibition. In contrast to wild-type, surviving dopaminergic SN neurons of homozygous weaver mouse exclusively expressed SUR1 + Kir6.2 during the active period of dopaminergic neurodegeneration. Therefore, alternative expression of K-ATP channel subunits defines the differential response to metabolic stress and constitutes a novel candidate mechanism for the differential vulnerability of dopaminergic neurons in response to respiratory chain dysfunction in Parkinson's disease.  (+info)

Inward rectification in KATP channels: a pH switch in the pore. (3/9961)

Inward-rectifier potassium channels (Kir channels) stabilize the resting membrane potential and set a threshold for excitation in many types of cell. This function arises from voltage-dependent rectification of these channels due to blockage by intracellular polyamines. In all Kir channels studied to date, the voltage-dependence of rectification is either strong or weak. Here we show that in cardiac as well as in cloned KATP channels (Kir6.2 + sulfonylurea receptor) polyamine-mediated rectification is not fixed but changes with intracellular pH in the physiological range: inward-rectification is prominent at basic pH, while at acidic pH rectification is very weak. The pH-dependence of polyamine block is specific for KATP as shown in experiments with other Kir channels. Systematic mutagenesis revealed a titratable C-terminal histidine residue (H216) in Kir6.2 to be the structural determinant, and electrostatic interaction between this residue and polyamines was shown to be the molecular mechanism underlying pH-dependent rectification. This pH-dependent block of KATP channels may represent a novel and direct link between excitation and intracellular pH.  (+info)

Cloning and characterization of the promoters of the maxiK channel alpha and beta subunits. (4/9961)

Large conductance, calcium-activated potassium (maxiK) channels are expressed in nerve, muscle, and other cell types and are important determinants of smooth muscle tone. To determine the mechanisms involved in the transcriptional regulation of maxiK channels, we characterized the promoter regions of the pore forming (alpha) and regulatory (beta) subunits of the human channel complex. Maximum promoter activity (up to 12.3-fold over control) occurred between nucleotides -567 and -220 for the alpha subunit (hSlo) gene. The minimal promoter is GC-rich with 5 Sp-1 binding sites and several TCC repeats. Other transcription factor-binding motifs, including c/EBP, NF-kB, PU.1, PEA-3, Myo-D, and E2A, were observed in the 5'-flanking sequence. Additionally, a CCTCCC sequence, which increases the transcriptional activity of the SM1/2 gene in smooth muscle, is located 27 bp upstream of the TATA-like sequence, a location identical to that found in the SM1/2 5'-flanking region. However, the promoter directed equivalent expression when transfected into smooth muscle and other cell types. Analysis of the hSlo beta subunit 5'-flanking region revealed a TATA box at position -77 and maximum promoter activity (up to 11.0-fold) in a 200 bp region upstream from the cap site. Binding sites for GATA-1, Myo-D, c-myb, Ets-1/Elk-1, Ap-1, and Ik-2 were identified within this sequence. Two CCTCCC elements are present in the hSlo beta subunit promoter, but tissue-specific transcriptional activity was not observed. The lack of tissue-specific promoter activity, particularly the finding of promoter activity in cells from tissues in which the maxiK gene is not expressed, suggests a complex channel regulatory mechanism for hSlo genes. Moreover, the lack of similarity of the promoters of the two genes suggests that regulation of coordinate expression of the subunits does not occur through equivalent cis-acting sequences.  (+info)

Genomic organization of the KCNQ1 K+ channel gene and identification of C-terminal mutations in the long-QT syndrome. (5/9961)

The voltage-gated K+ channel KVLQT1 is essential for the repolarization phase of the cardiac action potential and for K+ homeostasis in the inner ear. Mutations in the human KCNQ1 gene encoding the alpha subunit of the KVLQT1 channel cause the long-QT syndrome (LQTS). The autosomal dominant form of this cardiac disease, the Romano-Ward syndrome, is characterized by a prolongation of the QT interval, ventricular arrhythmias, and sudden death. The autosomal recessive form, the Jervell and Lange-Nielsen syndrome, also includes bilateral deafness. In the present study, we report the entire genomic structure of KCNQ1, which consists of 19 exons spanning 400 kb on chromosome 11p15.5. We describe the sequences of exon-intron boundaries and oligonucleotide primers that allow polymerase chain reaction (PCR) amplification of exons from genomic DNA. Two new (CA)n repeat microsatellites were found in introns 10 and 14. The present study provides helpful tools for the linkage analysis and mutation screening of the complete KCNQ1 gene. By use of these tools, five novel mutations were identified in LQTS patients by PCR-single-strand conformational polymorphism (SSCP) analysis in the C-terminal part of KCNQ1: two missense mutations, a 20-bp and 1-bp deletions, and a 1-bp insertion. Such mutations in the C-terminal domain of the gene may be more frequent than previously expected, because this region has not been analyzed so far. This could explain the low percentage of mutations found in large LQTS cohorts.  (+info)

Angiotensin II type 1 receptor-mediated inhibition of K+ channel subunit kv2.2 in brain stem and hypothalamic neurons. (6/9961)

Angiotensin II (Ang II) has powerful modulatory actions on cardiovascular function that are mediated by specific receptors located on neurons within the hypothalamus and brain stem. Incubation of neuronal cocultures of rat hypothalamus and brain stem with Ang II elicits an Ang II type 1 (AT1) receptor-mediated inhibition of total outward K+ current that contributes to an increase in neuronal firing rate. However, the exact K+ conductance(s) that is inhibited by Ang II are not established. Pharmacological manipulation of total neuronal outward K+ current revealed a component of K+ current sensitive to quinine, tetraethylammonium, and 4-aminopyridine, with IC50 values of 21.7 micromol/L, 1.49 mmol/L, and 890 micromol/L, respectively, and insensitive to alpha-dendrotoxin (100 to 500 nmol/L), charybdotoxin (100 to 500 nmol/L), and mast cell degranulating peptide (1 micromol/L). Collectively, these data suggest the presence of Kv2.2 and Kv3.1b. Biophysical examination of the quinine-sensitive neuronal K+ current demonstrated a macroscopic conductance with similar biophysical properties to those of Kv2.2 and Kv3.1b. Ang II (100 nmol/L), in the presence of the AT2 receptor blocker PD123,319, elicited an inhibition of neuronal K+ current that was abolished by quinine (50 micromol/L). Reverse transcriptase-polymerase chain reaction analysis confirmed the presence of Kv2.2 and Kv3.1b mRNA in these neurons. However, Western blot analyses demonstrated that only Kv2.2 protein was present. Coexpression of Kv2.2 and the AT1 receptor in Xenopus oocytes demonstrated an Ang II-induced inhibition of Kv2.2 current. Therefore, these data suggest that inhibition of Kv2.2 contributes to the AT1 receptor-mediated reduction of neuronal K+ current and subsequently to the modulation of cardiovascular function.  (+info)

Ionic currents underlying spontaneous action potentials in isolated cerebellar Purkinje neurons. (7/9961)

Acutely dissociated cell bodies of mouse Purkinje neurons spontaneously fired action potentials at approximately 50 Hz (25 degrees C). To directly measure the ionic currents underlying spontaneous activity, we voltage-clamped the cells using prerecorded spontaneous action potentials (spike trains) as voltage commands and used ionic substitution and selective blockers to isolate individual currents. The largest current flowing during the interspike interval was tetrodotoxin-sensitive sodium current (approximately -50 pA between -65 and -60 mV). Although the neurons had large voltage-dependent calcium currents, the net current blocked by cobalt substitution for calcium was outward at all times during spike trains. Thus, the electrical effect of calcium current is apparently dominated by rapidly activated calcium-dependent potassium currents. Under current clamp, all cells continued firing spontaneously (though approximately 30% more slowly) after block of T-type calcium current by mibefradil, and most cells continued to fire after block of all calcium current by cobalt substitution. Although the neurons possessed hyperpolarization-activated cation current (Ih), little current flowed during spike trains, and block by 1 mM cesium had no effect on firing frequency. The outward potassium currents underlying the repolarization of the spikes were completely blocked by 1 mM TEA. These currents deactivated quickly (<1 msec) after each spike. We conclude that the spontaneous firing of Purkinje neuron cell bodies depends mainly on tetrodotoxin-sensitive sodium current flowing between spikes. The high firing rate is promoted by large potassium currents that repolarize the cell rapidly and deactivate quickly, thus preventing strong hyperpolarization and restoring a high input resistance for subsequent depolarization.  (+info)

Inducible genetic suppression of neuronal excitability. (8/9961)

Graded, reversible suppression of neuronal excitability represents a logical goal of therapy for epilepsy and intractable pain. To achieve such suppression, we have developed the means to transfer "electrical silencing" genes into neurons with sensitive control of transgene expression. An ecdysone-inducible promoter drives the expression of inwardly rectifying potassium channels in polycistronic adenoviral vectors. Infection of superior cervical ganglion neurons did not affect normal electrical activity but suppressed excitability after the induction of gene expression. These experiments demonstrate the feasibility of controlled ion channel expression after somatic gene transfer into neurons and serve as the prototype for a novel generalizable approach to modulate excitability.  (+info)

TY - JOUR. T1 - ATP sensitive potassium channel openers. T2 - A new class of ocular hypotensive agents. AU - Roy Chowdhury, Uttio. AU - Dosa, Peter I.. AU - Fautsch, Michael P. PY - 2016/3/2. Y1 - 2016/3/2. N2 - ATP sensitive potassium (KATP) channels connect the metabolic and energetic state of cells due to their sensitivity to ATP and ADP concentrations. KATP channels have been identified in multiple tissues and organs of the body including heart, pancreas, vascular smooth muscles and skeletal muscles. These channels are obligatory hetero-octamers and contain four sulfonylurea (SUR) and four potassium inward rectifier (Kir) subunits. Based on the particular type of SUR and Kir present, there are several tissue specific subtypes of KATP channels, each with their own unique set of functions. Recently, KATP channels have been reported in human and mouse ocular tissues. In ex vivo and in vivo model systems, KATP channel openers showed significant ocular hypotensive properties with no appearance of ...
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TY - JOUR. T1 - The Role of the Voltage-Gated Potassium Channel Proteins Kv8.2 and Kv2.1 in Vision and Retinal Disease. T2 - Insights from the Study of Mouse Gene Knock-Out Mutations. AU - Hart, Nathan S. AU - Mountford, Jessica K. AU - Voigt, Valentina. AU - Fuller-Carter, Paula. AU - Barth, Melanie. AU - Nerbonne, Jeanne M. AU - Hunt, David M. AU - Carvalho, Livia S. PY - 2019/2. Y1 - 2019/2. N2 - Mutations in the KCNV2 gene, which encodes the voltage-gated K+ channel protein Kv8.2, cause a distinctive form of cone dystrophy with a supernormal rod response (CDSRR). Kv8.2 channel subunits only form functional channels when combined in a heterotetramer with Kv2.1 subunits encoded by the KCNB1 gene. The CDSRR disease phenotype indicates that photoreceptor adaptation is disrupted. The electroretinogram (ERG) response of affected individuals shows depressed rod and cone activity, but what distinguishes this disease is the supernormal rod response to a bright flash of light. Here, we have utilized ...
Title: Targeting Potassium Channels: New Advances in Cardiovascular Therapy. VOLUME: 3 ISSUE: 2. Author(s):Ramon Martinez-Marmol, Meritxell Roura-Ferrer and Antonio Felipe. Affiliation:Molecular Physiology Laboratory, Departament de Bioquimica i Biologia Molecular, Universitat de Barcelona, E-08028 Barcelona, Spain.. Keywords:Potassium channels, cardiovascular therapy, channelopathy, long QT syndrome, arrithmiogenesis, heart diseases. Abstract: Potassium channels, which are essential to a wide range of physiological processes, are involved in many diseases. Thus, alterations in such important proteins due to congenital deficiencies or to undesirable side-effects of common medications might lead to dysfunctions. Heart is one of those tissues where potassium channels play a crucial role. The maintenance of cardiac action potential appears to be the consequence of the varied activity of several types of potassium channels. Recently, compounds that modify cardiac potassium channel activity and so ...
TY - JOUR. T1 - Blockade of ATP-sensitive potassium channels prevents the attenuation of the exercise pressor reflex by tempol in rats with ligated femoral arteries. AU - Yamauchi, Katsuya. AU - Stone, Audrey J.. AU - Stocker, Sean D.. AU - Kaufman, Marc P.. PY - 2012/8/1. Y1 - 2012/8/1. N2 - We reported previously that tempol attenuated the exercise pressor and muscle mechanoreceptor reflexes in rats whose femoral arteries were ligated, whereas tempol did not attenuate these reflexes in rats whose femoral arteries were freely perfused. Although the mechanism whereby tempol attenuated these reflexes in rats whose femoral artery was ligated was independent of its ability to scavenge reactive oxygen species, its nature remains unclear. An alternative explanation for the tempol-induced attenuation of these reflexes involves ATP-sensitive potassium channels (K Atp) and calcium-activated potassium channels (BK Ca), both of which are opened by tempol. We tested the likelihood of this explanation by ...
Potassium ion (K+) channels are ubiquitous components and are widely distributed on the surface of the cell membrane in various tissues. There are many types of potassium ion channels (voltage-gated K+ channels, ATP-sensitive K+ channels, Ca2+-activated K+ channels, etc.), and each type of potassium ion channel has its own characteristic features concerning electrophysiology and molecular biology in each potassium ion channel. The potassium ion current across the plasma membrane is considered to have two main physiological functions, one for determining the membrane potential and the other regulating the electrical activity. Membrane hyperpolarization would reduce the excitability of the membrane by shifting the membrane potential away from the threshold for excitation and would inhibit, where it existed, calcium ion (Ca2+) influx through voltage-gated Ca2+ channels by closing the Ca2+ channel. Outward potassium ion currents activated upon depolarization would counteract the depolarizing action ...
Carr DB, McDonnell Moorehead T, Bouchard A, et al. Effects of injectable HPβCD-diclofenac on the human delayed rectifier potassium channel current in vitro and on proarrhythmic QTc in vivo. Clin Ther. 2013;35(5):646-658. doi:10.1016/j.clinthera.2013.03.014. View article
TY - JOUR. T1 - Squaring the Circle. T2 - A New Study of Inward and Outward-Rectifying Potassium Currents in U251 GBM Cells. AU - Ratto, Daniela. AU - Ferrari, Beatrice. AU - Roda, Elisa. AU - Brandalise, Federico. AU - Siciliani, Stella. AU - De Luca, Fabrizio. AU - Priori, Erica Cecilia. AU - Di Iorio, Carmine. AU - Cobelli, Filippo. AU - Veneroni, Paola. AU - Bottone, Maria Grazia. AU - Rossi, Paola. PY - 2020/7. Y1 - 2020/7. N2 - In the present study, the functional role of the inwardly rectifying K+ channel, Kir4.1, and large-conductance Ca2+-activated K+ (BK) channel during cell migration in U251 cell line was investigated. We focused on polarised cells which are positive for the active-Cdc42 migration marker. The perforated patch technique was used to avoid intracellular dialysis and to maintain physiological changes in intracellular calcium. Wound healing was employed to assay migration after 24 h. Polarised cells recorded displayed different hallmarks of undifferentiated glial cells: ...
Transient exposure to ethanol (EtOH) results in a massive neurodegeneration in the developing brain leading to behavioral and cognitive deficits observed in fetal alcohol syndrome. There is now compelling evidence that K+ channels play an important role in the control of programmed cell death. The aim of the present work was to investigate the involvement of K+ channels in the EtOH-induced cerebellar granule cell death and/or survival. At low and high concentrations, EtOH evoked membrane depolarization and hyperpolarization, respectively. Bath perfusion of EtOH (10 mM) depressed the I(A) (transient K+ current) potassium current whereas EtOH (400 mM) provoked a marked potentiation of the specific I(K) (delayed rectifier K+ current) current. Pipette dialysis with GTPgammaS or GDPbetaS did not modify the effects of EtOH (400 mM) on both membrane potential and I(K) current. In contrast, the reversible depolarization and slowly recovering inhibition of I(A) induced by EtOH (10 mM) became irreversible in the
Most information currently available regarding vascular K+ channel function in diabetes concerns KATP channels. As for chronic hypertension, there are now several reports of impaired vascular relaxant responses to synthetic openers of KATP channels in long-term diabetes. These studies have mostly utilized the streptozotocin-injected rat model of diabetes and have examined vessels at 2.5 to 4 months after streptozotocin treatment. In this model in which plasma glucose levels are increased 3- to 4-fold, impaired relaxation of the isolated aorta122 123 124 and mesenteric vascular bed125 and reduced dilatation of large126 and small127 cerebral arteries in vivo typically develop. These changes are thought to be the result of a decreased number of vascular KATP channels and/or reduced sensitivity of these channels to synthetic openers. Nonspecific cytotoxic effects of streptozotocin seem an unlikely cause of these changes because, like other manifestations of vascular dysfunction, abnormal vasodilator ...
Most information currently available regarding vascular K+ channel function in diabetes concerns KATP channels. As for chronic hypertension, there are now several reports of impaired vascular relaxant responses to synthetic openers of KATP channels in long-term diabetes. These studies have mostly utilized the streptozotocin-injected rat model of diabetes and have examined vessels at 2.5 to 4 months after streptozotocin treatment. In this model in which plasma glucose levels are increased 3- to 4-fold, impaired relaxation of the isolated aorta122 123 124 and mesenteric vascular bed125 and reduced dilatation of large126 and small127 cerebral arteries in vivo typically develop. These changes are thought to be the result of a decreased number of vascular KATP channels and/or reduced sensitivity of these channels to synthetic openers. Nonspecific cytotoxic effects of streptozotocin seem an unlikely cause of these changes because, like other manifestations of vascular dysfunction, abnormal vasodilator ...
Potassium channel molecule. Computer model showing the structure of a bacterial potassium channel with four units arranged around an axis going through the first (and only visible) of four potassium ions (big purple sphere). From Bacillus cereus. - Stock Image C035/8257
A recent study (1) gives insight into how the lipids in the cell membranes affect how well one particular potassium channel functions. The particular channel the researchers investigated is one of the most studied potassium channels. This channel demonstrates how the function of other channels and pumps also may be affected by the composition of the cell membranes.. The researchers showed that the pore that lets potassium flow through the channel is fine-tuned by the physical characteristics of the lipid in the cell membrane. When the membrane allows protein in the pore of the channel to change more easily, potassium can get through faster.. This study changed two characteristics of the membrane that potassium channels sit in. The two characteristics of the membrane that the researchers changed were the temperature of the membrane, and the type of fats the membrane was made of. Both of these characteristics changed the fluidity of the membrane.. The researchers then determined whether the ...
An electrochemical gating model is presented to account for the effects described in the companion paper by M. R. Silver, M. S. Shapiro, and T. E. DeCoursey (1994. Journal of General Physiology, 103:519-548) of Rb+ and Rb+/K+ mixtures on the kinetics and voltage dependence of an inwardly rectifying (IR) K+ channel. The model proposes that both Rb+ and K+ act as allosteric modulators of an intrinsically voltage dependent isomerization between open and closed states. Occupancy of binding sites on the outside of the channel promotes channel opening and stabilizes the open state. Rb+ binds to separate sites within the pore and plugs IR channels. Occupancy of the pore by Rb+ can modify the rates of isomerization and the affinity of the allosteric sites for activator ions. The model also incorporates the proposed triple-barreled nature of the IR channel (Matsuda, H., 1988. Journal of Physiology. 397:237-258.) by proposing that plugging of the channel is a cooperative process involving a single site in ...
Global Markets Directs, Potassium Voltage Gated Channel Subfamily C Member 1 (Voltage Gated Potassium Channel Subunit Kv3.1 or Voltage Gated Potassium Channel Subunit Kv4 or KCNC1) - Pipeline
This enabled them to draw conclusions about its mechanism of action, which they describe in the current issue of Nature Communications. Neurons conduct information by way of electrical impulses through our body. Potassium channels are a key component of this electrical circuit and are controlled either by an electrical impulse or through signaling molecules. In man, the dysfunction of the so-called HCN potassium channels is associated with neurological disorders such as epilepsy and depression. Prof. Henning Stahlbergs team at the Biozentrum of the University of Basel has now elucidated the full structure of a bacterial counterpart of this type of potassium channel, which has provided new insights into its functioning.. ...
This e-book presents an overview of the different substances capable of modulating potassium channels in relation to various clinical indications in cardiology, pulmonology, endocrinology and neurology. The possible benefits and side effects of potassium channel modulators is discussed in correlation with biophysical and pharmacological properties of ion channels. Readers will learn how mutation of K+ channels can be conferred by molecular processes such as alternative splicing, RNA editing and posttranslational modifications. Altogether, this e-book will be of use to clinical practitioners, electrophysiologists and pharmacologists interested in the complicated but fascinating science of potassium channels.. ...
Energy dissipating systems (uncoupling proteins - UCPs, alternative oxidase - AOX, mitochondrial potassium channels) in physiological and pathological conditions: the activity of UCPs and AOXs in different eukaryotic organisms, UCP proteins in inflammation and circulatory diseases, mitochondrial potassium channels in cytoprotection, mitochondria and the endurance ...
July 29, 2013. Just 12 molecules of water cause the long post-activation recovery period required by potassium ion channels before they can function again. Using molecular simulations that modeled a potassium channel and its immediate cellular environment, atom for atom, University of Chicago scientists have revealed this new mechanism in the function of a nearly universal biological structure, with implications ranging from fundamental biology to the design of pharmaceuticals. Their findings were published online July 28 in Nature.. Our research clarifies the nature of this previously mysterious inactivation state. This gives us better understanding of fundamental biology and should improve the rational design of drugs, which often target the inactivated state of channels said Benoît Roux, PhD, professor of biochemistry and molecular biology at the University of Chicago.. Potassium channels, present in the cells of virtually all living organisms, are core components in bioelectricity ...
Effects of KRN4884 (5-amino-,i,N,/i,-[2-(2-chlorophenyl)ethyl]-,i,N,/i,-cyano-3-pyridinecarboxamidine), a novel K,sup,+,/sup, channel opener, on ionic currents were examined in rabbit femoral arterial myocytes (RFAMs). Under whole-cell clamp conditions where cells were superfused with 5.9 mM K,sup,+,/sup, bathing solution, KRN4884 elicited an outward current at −30 mV. KRN4884-induced current had a reversal potential of −78 mV and was abolished by application of glibenclamide (glib). KRN4884 was approximately 43 times more potent than levcromakalim in activating an ATP-sensitive K,sup,+,/sup, current (I,sub,K-ATP,/sub,). On the other hand, KRN4884 affected neither voltage-dependent Ca,sup,2+,/sup, nor delayed rectifier K,sup,+,/sup, channel currents. In the inside-out patch clamp configuration where cells were superfused with the symmetrical 140 mM K,sup,+,/sup, solution, KRN4884 activated 47 pS K,sup,+,/sup, channels in the presence of adenosine diphosphate. Similar 47 pS K,sup,+,/sup, ...
The following figure shows the location of the disease-causing mutations in hKv8.2 in CDSRE patients examined in this study. Three of these, W450G, G459D, and G461R, are located in the pore region of the hKv8.2 α-subunit. The missense mutations G459D and G461R affect the first and second glycine, respectively, of the Gly-Tyr-Gly motif, the characteristic potassium channel signature sequence. To understand the functional consequences of these mutations, the corresponding mutations (W467G, G476D, and G478R) were introduced into mKv8.2, and their effect on subunit localization in COS7L cells was examined. Like mKv8.2, the expression of either mKv8.2-W467G-EGFP, mKv8.2-G476D-EGFP, or mKv8.2-G478R-EGFP resulted in an intracellular localization [1753]. Voltage-gated K+ channels selectively transfer potassium ions through the plasma membrane in response to depolarization. The ion-conducting core of voltage-gated K+ channels is composed of four Kv-alpha subunits, which also possess the voltage sensor. ...
Fig. 2. KCNE1 inhibits KCNQ1 currents and depolarizes embryonic cells. (A) Tail currents were analyzed at −120 mV and normalized to the value followed after the 60-mV depolarizing pulse to estimate the voltage dependence of channel activation (n = 10 or 11). At voltages of 0 mV or less, addition of KCNE1 reduced the currents compared with KCNQ1 alone. (B) KCNQ1 (5 ng of mRNA) was expressed alone or together with 0.2 ng of KCNE1 mRNA. Each lane was loaded with equal amounts of protein (as estimated by Bradford test and Ponceau staining). Four consecutive biotinylation Western blots detected no clear alterations of KCNQ1 protein in the plasma membrane (densitometric analysis of all four gels normalized to the respective KCNQ1 band gave 1.0061 ± 0.1025 for KCNQ1 + KCNE1 injections). Analysis of membrane potential in vivo using DiSBAC voltage reporter dye reveals that KCNE1 mRNA expression depolarizes cells in the neurulating embryo. (C) Histograms showing normalized frequencies corresponding to ...
Potassium channels selectively conduct K(+) ions across cell membranes and have key roles in cell excitability. Their opening and closing can be spontaneous or controlled by membrane voltage or ligand binding. We used Ba(2+) as a probe to determine the location of the ligand-sensitive gate in an inwardly rectifying K(+) channel (Kir6.2). To a K(+) channel, Ba(2+) and K(+) are of similar sizes, but Ba(2+) blocks the pore by binding within the selectivity filter. We found that internal Ba(2+) could still access its binding site when the channel was shut, which indicates that the ligand-sensitive gate lies above the Ba(2+)-block site, and thus within or above the selectivity filter. This is in marked contrast to the voltage-dependent gate of K(V) channels, which is located at the intracellular mouth of the pore.
Sensory neurons, life-science tools related to Chemosensory Receptors (Olfactory, Vomeronasal, Trace Amine-Associated), Visual, Auditory, TRP channels and other GPCRs.
Gene Information Potassium channels are present in most mammalian cells where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein which has a greater tendency to allow potassium to flow into a cell rather than out of a cell is controlled by G-proteins. It associates with another G-protein-activated potassium channel to form a heteromultimeric pore-forming complex. [provided by RefSeq Jul 2008]. ...
This review has focused on the properties of the ATP-sensitive K-channel found in cardiac and skeletal muscle, and in pancreatic beta-cells. It is conceivable that this channel will be found in other cell types. In particular, it would be worthwhile looking for its presence in those cells in which electrical activity is linked to metabolism, glucose concentration, or oxygen levels. Obvious examples are the glucoreceptor neurons of mammalian brain and chemoreceptors such as those of the carotid body. While ATP-sensitive K-channels in cardiac and skeletal muscle membranes are rather similar, there are a few significant differences between these channels and that found in the beta-cell. Most notably, the latter is more sensitive to inhibition by ATP and sulphonylureas. It remains to be seen whether they also differ in the ability of nucleotides to activate the channel. Considerable confusion also still surrounds the physiological regulation of the ATP-sensitive K-channel in intact cells. Although the
This gene encodes one of the members of the superfamily of potassium channel proteins containing two pore-forming P domains. The message for this gene is mainly expressed in the cortical distal tubules and collecting ducts of the kidney. The protein is highly sensitive to external pH and this, in combination with its expression pattern, suggests it may play an important role in renal potassium transport ...
Potassium channel (Protein Data Bank entry 1bl8) on a dark slate blue background with potassium ions shown in firebrick. The channel is comprised of four chains. Each chain has been rainbow-colored from blue at the N-terminus to red at the C-terminus, but only the surface of the channel is shown. The surface has been sliced with a per-model clipping plane. The surface cap color is plum except with opacity set to 0.8. The shininess and brightness have been set to 128 and 8, respectively, and the lights on the scene have been moved from their default positions. The subdivision quality (related to the smoothness of the spherical ions) is 5.0, and the molecular surface was computed with probe radius and vertex density set to 1.0 and 6.0, respectively. The entry Cavity and Tunnel Detection provides additional views of the same structure. ...
This is the Authors Original Manuscript of an article published by Taylor & Francis in Channels on 02 Jan 2018 available online: https://doi.org/10.1080/19336950.2017.1412151 ...
KCTD21 (potassium channel tetramerization domain containing 21), Authors: Dessen P. Published in: Atlas Genet Cytogenet Oncol Haematol.
BioAssay record AID 2432 submitted by Johns Hopkins Ion Channel Center: Mode of action assay - molecular determinants for ztz240, a potentiator of KCNQ2 potassium channels.
Lipkind GM, Hanck DA, Fozzard HA. A structural motif for the voltage-gated potassium channel pore. Proc Natl Acad Sci U S A. 1995 Sep 26; 92(20):9215-9 ...
BioAssay record AID 2258 submitted by Johns Hopkins Ion Channel Center: Summary of probe development for potentiators of KCNQ2 potassium channels.
Kv1.2 Potassium Channel information including symptoms, causes, diseases, symptoms, treatments, and other medical and health issues.
High quality reagents for receptor, ion channel and enzyme research including potassium channel tools from Hello Bio - a trusted, affordable life science reagents supplier.
Differences in the mechanism of metabolic regulation of ATP-sensitive K+ channels containing Kir6.1 and Kir6.2 subunits.: Kir6.1\SUR2B has intrinsic sensitivity
心不全によるK_,ATP,チャネルの変調 : レシピエントから得た心筋による検討 Alterations in ATP-sensitive potassium channel sensitivity to ATP in failing human hearts ...
Experiments described in this report provide a strong argument for the existence of two distinct current components (I KF andI KS) in the slow sustained voltage-activated K+ current (I K) in the larval muscles ofDrosophila. Voltage-activated K+ current in the larval muscles ofDrosophila has been previously resolved into two distinct currents. With the data presented here, we can now resolve the total voltage-activated K+ current into three components. Resolution of I K intoI KS andI KF will be particularly helpful in analyzing the properties of these two currents, deciphering the functional role of each current in muscle excitability, and studying mechanisms underlying their function and regulation.. Channels carrying I KS are encoded by the Shab gene. I KS shares properties with the current generated by expressing Shabchannels in Xenopus oocytes. These properties include relative resistance to blockade by 4-AP and a relatively slow activation (Covarrubias et al., 1991; Tsunoda and Salkoff, ...
Our laboratory studies potassium channels which are key elements which control and shape electrical activity in the brain, heart, and other excitable tissues. These channels are major determinants of behavior and higher brain function. The potassium channels we study are involved in human disease (e.g. epilepsy, cardiac arrhythmia), basic physiology (e.g. control of blood pressure, protection from hypoxia), and higher brain function (e.g. learning and memory). Our approach is a comparative genom
This MATLAB function returns filtered state probabilities FS from conducting optimal conditional inference of the probabilities of the operative latent states in the regime-switching data Y.
Next-day shipping cDNA ORF clones derived from KCNE2 potassium voltage-gated channel subfamily E regulatory subunit 2 available at GenScript, starting from $99.00.
The protein encoded by this gene is part of a potentially heterotetrameric voltage-independent potassium channel that is activated by intracellular calcium. Activation is
Int. J. Mol. Sci. 2002, 3 193 where M= M AM B=(M A+ M B) is the reduced mass of the nuclei Aand Bwith corresponding masses M A and M B, R is the vector connecting the nuclei, r denotes the set of the electronic coordinates measured from the centre of nuclear mass, and H el(r;R) is the so-called electronic Hamiltonian, which contains operators of the kinetic energy for the electrons and all ...
Katso sanan specific käännös englanti-suomi. Ilmainen Sanakirja on monipuolinen sanakirja netissä. Suomi, englanti, ruotsi ja monta muuta kieltä!
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Euroopa Liidu L 215 Teataja Eestikeelne väljaanne Õigusaktid 61. aastakäik 23. august 2018 Sisukord III Muud aktid EUROOPA MAJANDUSPIIRKOND EMP ühiskomitee otsus nr 216/2016, millega muudetakse EMP lepingu
Tumor necrosis factor alpha modulates sodium-activated potassium channel SLICK in rat dorsal horn neurons via p38 MAPK activation pathway Kun Wang,1 Feng Wang,1 Jun-Ping Bao,2 Zhi-Yang Xie,1 Lu Chen,1 Bao-Yi Zhou,1 Xin-Hui Xie,2 Xiao-Tao Wu1,2 1Medical School of Southeast University, 2Department of Orthopaedics, Zhongda Hospital, Southeast University, Nanjing, Peopleâ s Republic of China Abstract: The dorsal horn (DH) of the spinal cord is the integrative center that processes and transmits pain sensation. Abnormal changes in ion channel expression can enhance the excitability of pain-related DH neurons. Sodium-activated potassium (KNa) channels are highly expressed particularly in the central nervous system; however, information about whether rat DH neurons express the SLICK channel protein is lacking, and the direct effects on SLICK in response to inflammation and the potential signaling pathway mediating such effects are yet to be elucidated. Here, using cultured DH neurons, we have shown that
This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by external barium (By similarity).
This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium. Can form cardiac and smooth muscle-type KATP channels with ABCC9. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation (By similarity).
Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. KCNJ16 may be involved in the regulation of fluid and pH balance. In the kidney, together with KCNJ10, mediates basolateral K(+) recycling in distal tubules; this process is critical for Na(+) reabsorption at the tubules (PubMed:24561201 ...
Fluothane (halothane) is a small molecule pharmaceutical. Halothane was first approved as Fluothane on 1982-01-01. It is used to treat status asthmaticus in the USA. The pharmaceutical is active against potassium channel subfamily K member 9 and potassium channel subfamily K member 10. In addition, it is known to target potassium channel subfamily K member 2, potassium channel subfamily K member 12, potassium channel subfamily K member 3, potassium channel subfamily K member 5, potassium channel subfamily K member 13, potassium voltage-gated channel subfamily B member 1, G protein-activated inward rectifier potassium channel 2, and ferritin light chain.
Potassium channels, found throughout the animal and plant kingdoms, play important roles in maintaining membrane potentials and regulating action potential firing, shape, and duration, among other functions. Using the Xenopus laevis (frog) oocyte as model system, we induced high expression of sodium and potassium voltage-gated channels and recorded action potentials by a modification of the two-electrode voltage-clamp recording technique. The voltage-dependent sodium conductance was due to expression of the skeletal muscle NaV channel (NaV1.4) and the delayed rectifier voltage-dependent potassium conductance was due to expression of a Shaker (Kv1) potassium channel. Upon this background, we mixed different potassium-selective ion channels, such as inwardly rectifying potassium (KIR) channels, tandem pore domain (K2P) potassium channels and voltage-gated (KV) channels. We analyzed how these potassium channels affected firing thresholds, reliability of action potential generation, action potential
OBJECTIVE: To assess the influence of blocking smooth muscle large conductance Ca(2+) -activated K+ channels and voltage-gated K+ channels on the conducted dilation to ACh and isoproterenol. MATERIALS AND METHODS: Rat mesenteric arteries were isolated with a bifurcation, triple-cannulated, pressurized and imaged using confocal microscopy. Phenylephrine was added to the superfusate to generate tone, and agonists perfused into a sidebranch to evoke local dilation and subsequent conducted dilation into the feed artery. RESULTS: Both ACh- and isoproterenol-stimulated local and conducted dilation with similar magnitudes of decay with distance along the feed artery (2000μm: ∼15% maximum dilation). The gap junction uncoupler carbenoxolone prevented both conducted dilation and intercellular spread of dye through gap junctions. IbTx, TEA or 4-AP, blockers of large conductance Ca(2+) -activated K+ channels and voltage-gated K+ channels, did not affect conducted dilation to either agonist. A combination
TY - JOUR. T1 - Spontaneous contractions of the pig urinary bladder. T2 - The effect of ATP-sensitive potassium channels and the role of the mucosa. AU - Akino, Hironobu. AU - Chapple, Christopher R.. AU - McKay, Neil G.. AU - Cross, Rebecca L.. AU - Murakami, Shigetaka. AU - Yokoyama, Osamu. AU - Chess-Williams, Russell. AU - Sellers, Donna J.. PY - 2008/11. Y1 - 2008/11. N2 - OBJECTIVE: To investigate the influence of the mucosa on the inhibitory effects of the ATP-sensitive potassium channel (KATP channel) opener, cromakalim, on the spontaneous contractions of pig bladder strips from the bladder dome and trigone. Little is known about the influence of the mucosa on spontaneous contractions and whether the nature of these contractions differs between the bladder dome and trigone. MATERIALS AND METHODS: Paired longitudinal strips of female pig bladders were isolated from the dome and trigone. The mucosa was removed from one strip per pair and tissues were set up in organ baths. Spontaneous ...
The ATP-dependent potassium channels (KATP channels) were originally identified in isolated membrane patches prepared from guinea pig ventricular myocytes by Noma1 in 1983. Since their discovery in cardiac cells, KATP channels have also been discovered in many other tissues, such as smooth muscle, skeletal muscle, pancreas, and brain, in which they have been shown to couple cellular metabolism to membrane electrical activity.2 Primarily on the basis of studies using pharmacological tools, openers of KATP channels have been shown to elicit cardioprotective effects, whereas KATP channel antagonists have been shown to block the cardioprotective effects of KATP channel openers and the powerful protective effect produced by single or multiple brief episodes of ischemia to reduce myocardial infarct size, a phenomenon called ischemic preconditioning.3 Because the results of these previous studies were obtained indirectly by the use of pharmacological agonists and antagonists, the results of the present ...
TY - JOUR. T1 - Voltage-dependent potassium currents during fast spikes of rat cerebellar Purkinje neurons. T2 - Inhibition by BDS-I toxin. AU - Martina, Marco. AU - Metz, Alexia E.. AU - Bean, Bruce P.. PY - 2007/1/1. Y1 - 2007/1/1. N2 - We characterized the kinetics and pharmacological properties of voltage-activated potassium currents in rat cerebellar Purkinje neurons using recordings from nucleated patches, which allowed high resolution of activation and deactivation kinetics. Activation was exceptionally rapid, with 10-90% activation in about 400 μs at +30 mV, near the peak of the spike. Deactivation was also extremely rapid, with a decay time constant of about 300 μs near -80 mV. These rapid activation and deactivation kinetics are consistent with mediation by Kv3-family channels but are even faster than reported for Kv3-family channels in other neurons. The peptide toxin BDS-I had very little blocking effect on potassium currents elicited by 100-ms depolarizing steps, but the potassium ...
TY - JOUR. T1 - The energetic state within hibernating myocardium is normal during dobutamine despite inhibition of ATP-dependent potassium channel opening with glibenclamide. AU - McFalls, Edward O.. AU - Kelly, Rosemary F.. AU - Hu, Qingsong. AU - Mansoor, Abdul. AU - Lee, Joseph. AU - Kuskowski, Michael. AU - Sikora, Joseph. AU - Ward, Herbert B.. AU - Zhang, Jianyi. PY - 2007/11. Y1 - 2007/11. N2 - Within hibernating myocardium, it is uncertain whether a normal energetic state is present at baseline and whether maintaining that energy state during a catecholamine challenge is dependent on ATP-dependent potassium channel opening. In this study, 16 swine underwent a thoracotomy with placement of an external constrictor on the left anterior descending coronary artery (LAD) (hibernation model). Seven additional swine underwent a sham operation. At 10 wk, the myocardial energetic state in the LAD region was assessed by 31P-NMR spectroscopy, and the ratio of phosphocreatine to ATP (PCr/ATP) was ...
Potassium voltage-gated channel subfamily D member 2 is a protein that in humans is encoded by the KCND2 gene. It contributes to the cardiac transient outward potassium current (Ito1), the main contributing current to the repolarizing phase 1 of the cardiac action potential. Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shal-related subfamily, members of which form voltage-activated A-type potassium ion channels and are prominent in the repolarization phase of the ...
Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell. Eight transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Feb 2013 ...
In a previous study we reported the presence of a large conductance K+ channel in the membrane of endoplasmic reticulum (ER) from rat hepatocytes. The channel open probability (Po) appeared voltage dependent and reached to a minimum 0.2 at +50 mV. Channel activity in this case was found to be totally inhibited at ATP concentration 2.5 mM, glibenclamide 100 μM and tolbutamide 400 μM. Existing evidence indicates an impairment of endoplasmic reticulum functions in ER stress condition. Because ER potassium channels have been involved in several ER functions including cytoprotection, apoptosis and calcium homeostasis, a study was carried out to consider whether the ER potassium channel function is altered in a high fat diet model of ER stress. Male Wistar rats were made ER stress for 2 weeks with a high fat diet. Ion channel incorporation of ER stress model into the bilayer lipid membrane allowed the characterization of K+ channel. Our results indicate that the channel Po was significantly ...
Fig. 1 Reduction of functional TRESK channels in DRG neurons and its association with pain in bone lesion-bearing rats.. (A and B) TRESK immunofluorescence staining in ipsilateral L4/5 DRG neurons from naïve, phosphate-buffered saline (PBS)-injected, or bone-localized MRMT-1 tumor-bearing rats. Representative images (A) and a summary for the mean fluorescence intensity of TRESK immunostaining (B) are shown. n = 224 to 230 cells (from six rats) per time point per group. Two-way analysis of variance (ANOVA) followed by Bonferroni post hoc test: F3,1818 = 116.2, ***P , 0.001. (C and D) TRESK protein (C) and mRNA (D) abundance in the cells described in (A). n = 6 to 7 rats per time point per group. Two-way ANOVA followed by either Bonferroni post hoc test, F3,40 = 4.21 (C), or one-way ANOVA followed by Tukey post hoc test, F2,16 = 20.54 (D), ***P , 0.001. N, naïve; P, PBS; M, MRMT-1. (E and F) Representative TRESK current traces and a summary for the current density of both the total background ...
TY - JOUR. T1 - Up-regulation of A-type potassium currents protects neurons against cerebral ischemia. AU - Deng, Ping. AU - Pang, Zhi Ping. AU - Lei, Zhigang. AU - Shikano, Sojin. AU - Xiong, Qiaojie. AU - Harvey, Brandon K.. AU - London, Barry. AU - Wang, Yun. AU - Li, Min. AU - Xu, Zao C.. PY - 2011/9/1. Y1 - 2011/9/1. N2 - Excitotoxicity is the major cause of many neurologic disorders including stroke. Potassium currents modulate neuronal excitability and therefore influence the pathological process. A-type potassium current (IA) is one of the major voltage-dependent potassium currents, yet its roles in excitotoxic cell death are not well understood. We report that, following ischemic insults, the IA increases significantly in large aspiny (LA) neurons but not medium spiny (MS) neurons in the striatum, which correlates with the higher resistance of LA neurons to ischemia. Activation of protein kinase Cα increases IA in LA neurons after ischemia. Cultured neurons from transgenic mice lacking ...
Cerebellar granule neurons (CGNs) are one of the most populous cells in the mammalian brain. They express an outwardly rectifying potassium current, termed a
Recent cloning of a family of genes encoding inwardly rectifying K+ channels has provided the opportunity to explain some venerable problems in membrane biology. An expanding number of novel inwardly rectifying K+ channel clones has revealed multiple channel subfamilies that have specialized roles i …
Read Kinetic Analysis of the Inhibitory Effect of Glibenclamide on KATP Channels of Mammalian Skeletal Muscle, The Journal of Membrane Biology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
The anti-contractile effect of perivascular adipose tissue (PVAT) is an important mechanism in the modulation of vascular tone in peripheral arteries. Recent evidence has implicated the XE991-sensitive voltage-gated Kv (KCNQ) channels in the regulation of arterial tone by PVAT. However, until now the in vivo pharmacology of the involved vascular Kv channels with regard to XE991 remains undetermined, since XE991 effects may involve Ca2+ activated BKCa channels and/or voltage-dependent Kv1.5 channels sensitive to diphenyl phosphine oxide-1 (DPO-1). In this study, we tested whether Kv1.5 channels are involved in the control of mesenteric arterial tone and its regulation by PVAT. Our study was also aimed at extending our current knowledge on the in situ vascular pharmacology of DPO-1 and XE991 regarding Kv1.5 and BKCa channels, in helping to identify the nature of K+ channels that could contribute to PVAT-mediated relaxation. XE991 at 30 µM reduced the anti-contractile response of PVAT, but had no effects
Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, members of which allow nerve cells to efficiently repolarize following an action potential. It plays an essential role in T-cell proliferation and activation. This gene appears to be intronless and it is clustered together with KCNA2 and KCNA10 genes on chromosome 1.
Yılanı / dilatör yanıtları (basınç kasılmaların kâğıda çizilmesi kullanarak) ölçümleri ile paralel izole arteriyel miyositler (yama...
K11085 msbA; ATP-binding cassette, subfamily B, bacterial MsbA [EC:3.6.3.-] K11085 msbA; ATP-binding cassette, subfamily B, bacterial MsbA [EC:3.6.3.-] K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06147 ABCB-BAC; ATP-binding cassette, subfamily B, bacterial K06160 pvdE; putative pyoverdin transport system ATP-binding/permease protein K15738 uup; ABC transport system ATP-binding/permease protein K21397 K21397; ABC transport system ATP-binding/permease protein K21397 K21397; ABC transport system ATP-binding/permease protein K23163 sbp; sulfate/thiosulfate transport system substrate-binding protein K02046 cysU; ...
Potassium Channels Inhibitors on signaling pathway are available at Adooq Bioscience. Check Potassium Channels pathway , inhibitors reviews and assay information.
In this recent study the researchers discovered a change in a potassium channel that is a major cause of secondary hypertension. Remember that normally an increase in aldosterone leads to an increase in sodium reabsorption in the kidney and a rise in blood pressure. Normally when there is an increase in potassium outside the cell, potassium will move into the cell.. In certain adrenal gland cells the resulting increase in membrane polarization (the difference in electrical charges across the membrane) leads to less aldosterone secretion. The lowering of aldosterone leads to less sodium reabsorption in the kidney, and thus lower blood pressure. In some people blood pressure is high and does not come down, because they have a gene that prevents this normal sequence.. In this particular study, a gene variant was found that affected part of a potassium channel. The change meant that the channel no longer allowed only potassium to pass. The channel allowed sodium to pass through the potassium channel ...
A compound of formula (I) wherein A, X, Y, Z, R.sub.1 and R.sub.24 are described herein. The compounds are useful as inhibitors of potassium channel function and in the treatment and prevention of arrhythmia, I.sub.Kur-associated disorders, and other disorders mediated by ion channel function. ##STR00001##
History Early advancement of cardiac hypertrophy may be beneficial but suffered hypertrophic activation leads to myocardial dysfunction. the delayed outward rectifier potassium current (IK) and the instantaneous inward rectifier potassium current (IK1) and Akt activity respectively. Results Hypertrophied cardiomyocytes showed reduction in IK and IK1. Treatment with captopril alleviated this JTP-74057 difference seen between JTP-74057 sham and shunt cardiomyocytes. Acute administration of ANG II (10?6M) to cardiocytes treated with captopril reduced IK and IK1 in shunts but not in sham. Captopril treatment reversed SPP1 ANG II effects on IK and IK1 in a PI3-K-independent manner. However in the absence of angiotensin transforming enzyme inhibition ANG II increased both IK and IK1 in a PI3-K-dependent manner in hypertrophied cardiomyocytes. Conclusions Thus captopril treatment reveals a negative effect of ANG II on IK and IK1 which is usually PI3-K impartial whereas in the absence of angiotensin ...
Vernakalant Hcl(RSD-1235) is an investigational mixed ion channel blocker that can terminate acute atrial fibrillation (AF) in humans at 2 to 5 mg/kg and may be more atrial-selective than available agents; in treatment of antiarrhythmic ...
The protein encoded by this gene forms a potassium channel that is thought to play a critical role in the regulation of neuronal excitability, particularly in sensory cells of the cochlea. The current generated by this channel is inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. The encoded protein can form a homomultimeric potassium channel or possibly a heteromultimeric channel in association with the protein encoded by the KCNQ3 gene. Defects in this gene are a cause of nonsyndromic sensorineural deafness type 2 (DFNA2), an autosomal dominant form of progressive hearing loss. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008 ...
Endogenous voltage-gated potassium currents were investigated in human embryonic kidney (HEK293) and Chinese hamster ovary (CHO) cells using whole-cell voltage clamp recording. Depolarizing voltage steps from -70 mV triggered an outwardly rectified current in nontransfected HEK293 cells. This current had an amplitude of 296 pA at +40 mV and a current density of 19.2 pA/pF. The outward current was eliminated by replacing internal K+ with Cs+ and suppressed by the K+ channel blockers tetraethylammonium and 4-aminopyridine. Raising external K+ attenuated the outward current and shifted the reversal potential towards positive potentials as predicted by the Nernst equation. The current had a fast activation phase but inactivated slowly. These features implicate delayed rectifier (I(K))-like channels as mediators of the observed current, which was comparable in size to I(K) currents in many other cells. A small native inward rectifier current but no transient outward current I(A), the M current I(M), ...
Planar silicon chips with 1-2-μm etched holes (average resistance: 2.04 ± 0.02 MΩ in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been developed using this technology. A single-channel prototype of the QPatch system was used for validation of the patch-clamp chip technology. We present here data on the quality of patch-clamp recordings and from actual drug screening studies of human potassium channels expressed in cultured cell lines. Using Chinese hamster ovary (CHO) and human embryonic kidney cells (HEK), gigaseals of 4.1 ± 0.4 GΩ (n = 146) and high-quality whole-cell current recordings were obtained from hERG and KCNQ4 potassium channels. Success rates for gigaseal recordings varied from 40 to 95%, and 67% of the whole-cell configurations lasted for ,20 min. Cells were maintained in suspension up to 4 h in a cell storage facility that is ...
Planar silicon chips with 1-2-μm etched holes (average resistance: 2.04 ± 0.02 MΩ in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been developed using this technology. A single-channel prototype of the QPatch system was used for validation of the patch-clamp chip technology. We present here data on the quality of patch-clamp recordings and from actual drug screening studies of human potassium channels expressed in cultured cell lines. Using Chinese hamster ovary (CHO) and human embryonic kidney cells (HEK), gigaseals of 4.1 ± 0.4 GΩ (n = 146) and high-quality whole-cell current recordings were obtained from hERG and KCNQ4 potassium channels. Success rates for gigaseal recordings varied from 40 to 95%, and 67% of the whole-cell configurations lasted for ,20 min. Cells were maintained in suspension up to 4 h in a cell storage facility that is ...
InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.
The study which was led by Winthrop Professor David Hunt from UWAs Neuroecology Group and Lions Eye Institute, and included researchers from University College London, was published recently in the international Journal of Biological Chemistry.. Professor Hunt and his colleagues examined the genetic origins of a blinding disorder, in which symptoms include a loss of central vision and visual acuity, progressing on to a severe impairment of vision.. Earlier research found the disorder was caused by mutations in the gene that encodes a particular potassium channel protein, and Professor Hunt and his team looked at the effects of mutant channel proteins on the overall function of potassium channels.. Potassium channels are found throughout most living organisms and generate electrical signals. In the eye, the channels affect the function of cone and rod photoreceptors and the presence of mutant forms of channel proteins can be diagnosed quite specifically by a patients particular reaction to ...
The actions of the opioid agonist U50488H on I-A and I-K were examined in acutely isolated mouse hippocampal CA3 pyramidal neurons using the whole-cell patch clamp technique. U50488H caused a concentration dependent, rapidly developing and reversible inhibition of voltage-activated I-A and I-K. The inhibitory actions were still observed in the presence of 30 muM naloxone or 5 muM nor-binaltorphimine dihydrochloride. The IC50 values for the blockade of I-A and I-K were calculated as 20.1.9 and 3.7 muM, respectively. In the presence of 3.3 muM U50488H, repetitive stimulation induced use-dependent inhibition of I-A and I-K. A 10 muM concentration of U50488H positively shifted the half-activation membrane potential of I-A by +11 mV, but negatively shifted I-K by -14 mV. These results demonstrate that U50488H can directly inhibit neuronal I-A and I-K without involvement of the activation of kappa -opioid receptors. (C) 2001 Elsevier Science B.V. All rights ...
The Kvβ subunit of voltage-dependent potassium (Kv) channels has structural similarity to aldo-keto reductases (AKRs), enzymes that catalyze reduction of aldehyde groups to alcohols that are coupled to oxidation of an NADPH cofactor. However, it was unclear whether the Kvβ protein functioned in a catalytic capacity in its interaction with Kv channels, which allow voltage-sensitive conductance of potassium ions that is critical for action potentials in excitable cells. Weng et al. used spectrophotometric assays to show that purified rat Kvβ2 had associated NADPH and could reduce small-molecule aldehydes known to serve as substrates for other AKRs. Under other conditions, Kvβ2 could promote the reverse reaction--transfer of a hydride from an alcohol to reduce NADP+. Mutation of residues in the active site of the enzyme diminished the enzymatic activity. Application of a Kvβ substrate to Kv channels in inside-out patches from oocytes expressing the channel subunits decreased channel ...
... see potassium channel blocker and potassium channel opener. Potassium channels have a tetrameric structure in which four ... Potassium channel blockers inhibit the flow of potassium ions through the channel. They either compete with potassium binding ... Proteopedia channel Potassium channel in 3D Potassium+Channels at the US National Library of Medicine Medical Subject Headings ... Calcium channel - Ion channel complex through which calcium ions pass Inward-rectifier potassium ion channel Potassium in ...
A potassium channel opener is a type of drug which facilitates ion transmission through potassium channels. Some examples ... June 2007). "Potassium channel opener pinacidil induces relaxation of the isolated human radial artery". J. Pharmacol. Sci. 104 ... Main MJ, Cryan JE, Dupere JR, Cox B, Clare JJ, Burbidge SA (August 2000). "Modulation of KCNQ2/3 potassium channels by the ... Sudo H, Yogo K, Ishizuka N, Otsuka H, Horie S, Saito K (November 2008). "Nicorandil, a potassium channel opener and nitric ...
Calcium channel Potassium channel Sodium channel Schrempf H, Schmidt O, Kümmerlen R, Hinnah S, Müller D, Betzler M, Steinkamp T ... KcsA (K channel of streptomyces A) is a prokaryotic potassium channel from the soil bacterium Streptomyces lividans that has ... The KcsA channel is considered a model channel because the KcsA structure provides a framework for understanding K+ channel ... KcsA studies are focused on using the prokaryotic channel as a model for the channel dynamics of larger eukaryotic K+ channels ...
... s are agents which interfere with conduction through potassium channels. Potassium channel blockers ... Potassium channel Potassium channel opener Amiodarone also blocks CACNA2D2-containing voltage gated calcium channels works by ... Sulfonylureas, such as gliclazide, are ATP-sensitive potassium channel blockers. Dalfampridine, A potassium channel blocker has ... blocks potassium channels of the hERG-type Primarily inhibits outward voltage-gated Kv2.1 potassium channel currents. a very ...
Calcium-activated potassium channels are potassium channels gated by calcium, or that are structurally or phylogenetically ... Subtypes of IK Channels KCa3.1 (IKCa1, SK4, KCNN4) Small conductance calcium activate potassium channels are quite different ... It is known that IK channels are modulated by calmodulin, whereas BK channels are not. IK channels have shown a strong ... Channels at the US National Library of Medicine Medical Subject Headings (MeSH) "Calcium-Activated Potassium Channels". IUPHAR ...
Potassium channels are the most diverse group of the ion channel family. They are important in shaping the action potential, ... the KCNQ channels (originally known as KvLQT channels); the EAG-like K+ channels; and three types of calcium (Ca)-activated K+ ... Sansom MS (2000). "Potassium channels: watching a voltage-sensor tilt and twist". Curr. Biol. 10 (5): R206-9. doi:10.1016/S0960 ... The potassium channel family is composed of several functionally distinct isoforms, which can be broadly separated into 2 ...
... potassium channel blocker and potassium channel opener. Ion channel Ion channel family Potassium channel tetramerisation domain ... Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in ... Channels at the US National Library of Medicine Medical Subject Headings (MeSH) "Voltage-Gated Potassium Channels". IUPHAR ... Gly sequences from the four channel subunits [1]. It may seem counterintuitive that a channel should allow potassium ions but ...
An ATP-sensitive potassium channel (or KATP channel) is a type of potassium channel that is gated by intracellular nucleotides ... bred to have ATP-insensitive potassium channels. In the pancreas, these channels were always open, but remained closed in the ... "ATP-dependent potassium channel from rat liver mitochondria: inhibitory analysis, channel clusterization". Membr Cell Biol. 10 ... ATP-sensitive potassium channels are composed of Kir6.x-type subunits and sulfonylurea receptor (SUR) subunits, along with ...
Inward-rectifier potassium channels (Kir, IRK) are a specific lipid-gated subset of potassium channels. To date, seven ... such as the delayed rectifier and A-type potassium channels. Those more "typical" potassium channels preferentially carry ... These channels differ from the potassium channels that are typically responsible for repolarizing a cell following an action ... 1995). "Inward rectifier potassium channels in plants differ from their animal counterparts in response to voltage and channel ...
VKCDB (Voltage-gated potassium Channel DataBase) is a database of functional data about the voltage-gated potassium channels. ... Voltage-gated potassium channel Li, Bin; Gallin Warren J (Jan 2004). "VKCDB: voltage-gated potassium channel database". BMC ... http://vkcdb.biology.ualberta.ca v t e (Biological databases, Electrophysiology, Ion channels, All stub articles, Biological ...
The potassium channel RNA editing signal is an RNA element found in human Kv1.1 and its homologues which directs the efficient ... Page for Potassium channel RNA editing signal at Rfam v t e (Cis-regulatory RNA elements, All stub articles, Molecular and ... Bhalla T, Rosenthal JJ, Holmgren M, Reenan R (October 2004). "Control of human potassium channel inactivation by editing of a ... The ADAR modification causes an isoleucine/valine recoding event which lies in the ion-conducting pore of the potassium channel ...
Below is a list of the 15 known two-pore-domain human potassium channels: Ion channel Potassium channel Goldstein SA, Bayliss ... Tandem+Pore+Domain+Potassium+Channel at the US National Library of Medicine Medical Subject Headings (MeSH) "Two-P Potassium ... Compendium of voltage-gated ion channels: potassium channels". Pharmacological Reviews. 55 (4): 583-6. doi:10.1124/pr.55.4.9. ... The two-pore-domain or tandem pore domain potassium channels are a family of 15 members that form what is known as leak ...
Page for Voltage-gated potassium-channel Kv1.4 IRES at Rfam v t e (GO template errors, Cis-regulatory RNA elements, All stub ... This family represents the Kv1.4 voltage-gated potassium channel internal ribosome entry site (IRES). This region has been ... noncoding region of a voltage-gated potassium channel mRNA". The Journal of Biological Chemistry. 279 (46): 47419-47430. doi: ...
An Ether-a-go-go potassium channel is a Potassium channel which is Inwardly-rectifying and voltage-gated. Examples include hERG ... v t e (Articles lacking sources from November 2019, All articles lacking sources, Potassium channels, All stub articles, ...
... potassium channel beta subunit is a family of proteins comprising the beta subunits of calcium-activated potassium channels. ... The functional diversity of potassium channels can arise through homo- or hetero-associations of alpha subunits or association ... "The beta subunit increases the Ca2+ sensitivity of large conductance Ca2+-activated potassium channels by retaining the gating ... "Functional role of the beta subunit of high conductance calcium-activated potassium channels". Neuron. 14 (3): 645-50. doi: ...
G protein-coupled inwardly-rectifying potassium channels are a type of G protein-gated ion channels because of this direct ... The G protein-coupled inwardly-rectifying potassium channels (GIRKs) are a family of lipid-gated inward-rectifier potassium ion ... causes an outward current of potassium, which slows down the heart rate. These are called muscarinic potassium channels (IKACh ... Examples of GIRKs include a subset of potassium channels in the heart, which, when activated by parasympathetic signals such as ...
BK channel Calcium-activated potassium channel Voltage-gated potassium channel GRCh38: Ensembl release 89: ENSG00000156113 - ... Calcium-activated potassium channel subunit alpha-1 also known as large conductance calcium-activated potassium channel, ... subfamily M, alpha member 1 (KCa1.1), or BK channel alpha subunit, is a voltage gated potassium channel encoded by the KCNMA1 ... Structure of the intracellular gating ring from the human high-conductance Ca2+ gated K+ channel (BK Channel) BK channels are ...
... potassium-channel. Potassium Channel. 1 August 2017. Retrieved 18 September 2017. "SH2D3A Gene". genecards.org. Gene Cards. ...
In 1998, Roderick MacKinnon's laboratory elucidated the structure and mechanism of a potassium channel, explaining how ... Jennifer Fisher Wilson (January 9, 2020). "Potassium Ion Channels". The Scientist. Retrieved November 1, 2021. Nicholas Wade ( ... Lasker Award winner who specializes in cell signaling by ion channels, neurotransmitters and hormones. Mandë Holford, Professor ...
These include the sodium, potassium, calcium, ryanodine receptor, HCN, CNG, CatSper, and TRP channels. This large group of ion ... Durell SR, Guy HR (2001). "A family of putative Kir potassium channels in prokaryotes". BMC Evolutionary Biology. 1: 14. doi: ... This also includes the 2-TM inward-rectifier potassium channels (Pfam PF01007) found primarily in eukaryotes. There are ... Milkman R (April 1994). "An Escherichia coli homologue of eukaryotic potassium channel proteins". Proceedings of the National ...
More specifically, SUR proteins are subunits of the inward-rectifier potassium ion channels Kir6.x (6.1 and 6.2). The ... Hence, the KATP channel monitors the energy balance within the cell. Depending on the tissue in which the KATP channel is ... Campbell JD, Sansom MS, Ashcroft FM (November 2003). "Potassium channel regulation". EMBO Reports. 4 (11): 1038-42. doi:10.1038 ... "ATP-dependent potassium channel blockade strengthens microglial neuroprotection after hypoxia-ischemia in rats". Experimental ...
Nichol's research investigates the biology of ion channels, particularly potassium channels, and their role in diabetes ... Nichols, C. G.; Lopatin, A. N. (1997). "Inward Rectifier Potassium Channels". Annual Review of Physiology. 59: 171-191. doi: ... Nichols, C. G.; Lederer, W. J. (1991). "Adenosine triphosphate-sensitive potassium channels in the cardiovascular system". The ... Nomenclature and Molecular Relationships of Inwardly Rectifying Potassium Channels". Pharmacological Reviews. 57 (4): 509-26. ...
January 2020). "2+-activated potassium channels". Proceedings of the National Academy of Sciences of the United States of ... channels. It is thought that dopamine neuron survival and behavioral abnormalities are due to the over expression of LINGO-1 in ...
BmP05 acts blocks the Ca2+-activated K+ channel (SKCa), whereas BmP02 acts on potassium channels, but is not able to exert a ... Xu Y, Wu J, Pei J, Shi Y, Ji Y, Tong Q (November 2000). "Solution structure of BmP02, a new potassium channel blocker from the ... BmP02 targets potassium channels. Its activity has been shown in Kv1.1-Kv1.3, Kv4.2, Shaker-IR (Inactivation Removed) type, and ... The Kv 4.2 channel partially mediates the transient outward potassium current (Ito) in adult rat ventricular myocytes. Three ...
Potassium channel, subfamily K, member 7, also known as KCNK7 or K2P7.1 is a protein which is encoded in humans by the KCNK7 ... "Entrez Gene: potassium channel". Strausberg RL, Feingold EA, Grouse LH, et al. (2002). "Generation and initial analysis of more ... K2P7.1 is a potassium channel containing two pore-forming P domains. Multiple transcript variants encoding different isoforms ... This gene encodes a member of the superfamily of potassium channel proteins containing two pore-forming P domains. The product ...
SK channels (small conductance calcium-activated potassium channels) are a subfamily of calcium-activated potassium channels. ... SK potassium channels share the same basic architecture with Shaker-like voltage-gated potassium channels. Four subunits ... SK channels may assemble as homotetrameric channels or as heterotetrameric channels, consisting of more than one SK channel ... SK channels are a type of ion channel allowing potassium cations to cross the cell membrane and are activated (opened) by an ...
K+ channels. HgTX1 shows high affinity with Kv1.1, Kv1.2, Kv1.3 voltage-gated potassium channels, but much lower affinity with ... Potassium channel inhibitor family. Alpha-KTx 2 subfamily. There are five subtypes known of the hongotoxin peptide. HgTX1 is 39 ... Hongotoxin (HgTX) is an ion channel toxin, which blocks Shaker-type (Kv1) K+ channels. The toxin is derived from the venom of ... HgTX4 and HgTX5 are potent selective inhibitors of Kv1 voltage-gated potassium channels (By similarity). ND, not determined. ...
Some potassium channels: Inward-rectifier potassium channels: These channels allow potassium ions to flow into the cell in an " ... Potassium channels Voltage-gated potassium channels e.g., Kvs, Kirs etc. Calcium-activated potassium channels e.g., BKCa or ... Sodium channels Voltage-gated sodium channels (NaVs) Epithelial sodium channels (ENaCs) Calcium channels (CaVs) Proton channels ... potassium channels are gated by lipids including the inward-rectifier potassium channels and two pore domain potassium channels ...
It binds to several subclasses of voltage-gated potassium channels (Kv channels), including Kv1.1, Kv1.6, and less potently to ... By blocking potassium channels, the MCD peptide can increase the duration of action potentials and increase neuronal ... This toxicity is caused by the blockage of voltage-gated potassium channels by the MCD peptide. However, there is no toxicity ... In addition, it is a potent blocker of voltage-sensitive potassium channels. MCD peptide is a component of bumblebee ( ...
Dreyer, Ingo; Uozumi, Nobuyuki (2011-11-01). "Potassium channels in plant cells". FEBS Journal. 278 (22): 4293-4303. doi: ... Since glucose is a large molecule, it requires a specific channel to facilitate its entry across plasma membranes and into ... transport of particular ions such as potassium down their charge gradient through high affinity transporters and channels. An ... Chen, Lihong; Tuo, Biguang; Dong, Hui (2016-01-14). "Regulation of Intestinal Glucose Absorption by Ion Channels and ...
... is an inward-rectifier potassium ion channel. Inwardly rectifying potassium channels, such as Kir2.6, maintain resting ... The Kir2.6 also known as inward rectifier potassium channel 18 is a protein that in humans is encoded by the KCNJ18 gene. ... January 2010). "Mutations in potassium channel Kir2.6 cause susceptibility to thyrotoxic hypokalemic periodic paralysis". Cell ...
... potassium chloride) to reduce osmotic stress. Potassium levels are not at equilibrium with the environment, so H. salinarum ... Reilly, Michael; The Discovery Channel. "World's oldest known DNA discovered". Retrieved 3 September 2010. Park, J. S.; ... Pérez-Fillol, M; Rodríguez-Valera, F (1986). "Potassium ion accumulation in cells of different halobacteria". Microbiología. 2 ... expresses multiple active transporters that pump potassium into the cell. At extremely high salt concentrations, protein ...
For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell ... Inorganic elements play critical roles in metabolism; some are abundant (e.g. sodium and potassium) while others function at ... About 99% of a human's body weight is made up of the elements carbon, nitrogen, calcium, sodium, chlorine, potassium, hydrogen ... The most important ions are sodium, potassium, calcium, magnesium, chloride, phosphate and the organic ion bicarbonate. The ...
Liu J, Xia J, Cho KH, Clapham DE, Ren D (June 2007). "CatSperbeta, a novel transmembrane protein in the CatSper channel complex ... This protein is deactivated by binding ATP, and activated by its dephosphorylation to ADP, which requires a potassium ion to ... Liu J, Xia J, Cho KH, Clapham DE, Ren D (June 2007). "CatSperbeta, a novel transmembrane protein in the CatSper channel complex ... It later becomes incorporated into the CatSper complex, a specialized calcium ion channel that enables spermatozoa motility. ...
Potassium channels are the largest and most diverse class of voltage-gated channels, with over 100 encoding human genes. These ... Voltage-gated ion-channels are usually ion-specific, and channels specific to sodium (Na+), potassium (K+), calcium (Ca2+), and ... Potassium channels differ in structure from the other channels in that they contain four separate polypeptide subunits, while ... some channels, such as inward-rectifier potassium ion channels, are activated instead by hyperpolarization. The gate is thought ...
... is a potassium channel opener. Puddu, Paolo Emilio; Garlid, Keith D; Monti, Francesco; Iwashiro, Katsunori; Picard, ... Potassium channel openers, 2-Pyridones, Benzopyrans, Nitriles, All stub articles, Cardiovascular system drug stubs). ... A Promising KATP Channel Activating Agent". Cardiovascular Drug Reviews. 18: 25. doi:10.1111/j.1527-3466.2000.tb00031.x. v t e ...
Abrogating the ion channel or pore function of viroporins, either through mutations that block conductance without disrupting ... which is selective for potassium ions. An alternative mechanism is illustrated by the SARS-CoV E protein, which forms a pore ... Pinto LH, Holsinger LJ, Lamb RA (May 1992). "Influenza virus M2 protein has ion channel activity". Cell. 69 (3): 517-28. doi: ... Viroporins are capable of assembling into oligomeric ion channels or pores in the host cell's membrane, rendering it more ...
... there is a short-circuit channel (i.e. a highly K-permeable ion channel) for potassium in the membrane, thus the voltage across ... The sodium-potassium pump (sodium-potassium adenosine triphosphatase, also known as Na⁺/K⁺-ATPase, Na⁺/K⁺ pump, or sodium- ... The sodium-potassium pump mechanism moves 3 sodium ions out and moves 2 potassium ions in, thus, in total, removing one ... that binds potassium, when it is in a phosphorylated state, to transfer potassium inside the cell" After this essential binding ...
1 September 2001). "AHippocampal heterotopia lack functional Kv4.2 potassium channels in the methylazoxymethanol model of ... hippocampal neurons in the MAM model were shown to have reduced potassium current function and expression for the Kv4.2 channel ...
Finance Minister Gibril Ibrahim estimated in 2021 that only 20% of Sudan's gold output went through official channels. ... a clay mineral consisting of potassium and Aluminium silicate, is found in some areas of Khartoum and in the south of the River ...
Other potassium channels like large conductance calcium-dependent potassium channels and sodium chloride dependent potassium ... Moreover, ATP-dependent potassium channels help neurons detect changes in energy or oxygen levels to modify breathing patterns ... The channels are regulated by G protein-coupled receptors that can activate or inhibit the NALCN channels depending on the ... Although the exact role of potassium currents is still being investigated, it appears that potassium and sodium leak currents ...
... serum potassium levels must be sufficiently high or dangerously low blood potassium levels may result. Once potassium levels ... calcium channel blockers, and phenytoin) HHS is usually precipitated by an infection, myocardial infarction, stroke or another ... Potassium replacement is often required as the metabolic problems are corrected. It is generally replaced at a rate 10 mEq per ... Potassium replacement is often required as the metabolic problems are corrected. Efforts to prevent diabetic foot ulcers are ...
A notable improvement was the addition of channels in the previously flat rice fields that allowed for the fish to continue ... Water and soil fertility were also affected by the increase in nitrogen, phosphorus and potassium. The symbiosis presents an ...
One calculation by Y. Gambhir et al., analyzing nuclear binding energy and stability in various decay channels, suggests a ... which would be lower than those of all known elements except for the alkali metals potassium, rubidium, caesium, and francium: ...
Zhang H, Cuevas J (June 2005). "sigma Receptor activation blocks potassium channels and depresses neuroexcitability in rat ... The σ1 receptor has been shown to appear in a complex with voltage gated K+ channels (Kv1.4 and Kv1.5), leading to the idea ... and inhibition of voltage gated K+ channels. The reasons for these effects are not well understood, even though σ1 receptors ... "Membrane-delimited coupling between sigma receptors and K+ channels in rat neurohypophysial terminals requires neither G- ...
"Influence of protein surface charge on the bimolecular kinetics of a potassium channel peptide inhibitor". Biochemistry. 32 (27 ... This has particularly important ramifications on the activity of proteins that function as enzymes or membrane channels, mainly ...
... closing calcium channels, and opening potassium channels. Opioids like oxycodone are thought to produce their analgesic effects ...
A year after the sodium discovery, Potter and Morgan reported that potassium (K) is also present in the exosphere of Mercury, ... During its 2009 flyby, the Ultraviolet and Visible Spectrometer (UVVS) channel of the Mercury Atmospheric and Surface ... potassium and water vapor, with a combined pressure level of about 10−14 bar (1 nPa). The exospheric species originate either ... probe in 2009 showed that calcium is concentrated mainly near the equator-opposite to what is observed for sodium and potassium ...
August 2007). "Inhibition of the HERG potassium channel by the tricyclic antidepressant doxepin". Biochemical Pharmacology. 74 ... Doxepin is also a potent blocker of voltage-gated sodium channels, and this action is thought to be involved in both its ... Bertelsen, Anne K.; Backonja, Misha-Miroslav (2007). "Drugs Targeting Voltage-Gated Sodium and Calcium Channels". Encyclopedia ... Sodium channel blockers, Tricyclic antidepressants, Wikipedia medicine articles ready to translate). ...
... anesthetic-activated potassium leak channel, KCNK3, is regulated by 14-3-3β-dependent, protein kinase C (PKC)-mediated ... They can also inhibit glutamate release and can modulate voltage-dependent calcium channels. Group I mGluRs, but not other ... Instead, they activate biochemical cascades, leading to the modification of other proteins, such as ion channels. This can lead ... Dingledine R, Borges K, Bowie D, Traynelis SF (March 1999). "The glutamate receptor ion channels". Pharmacological Reviews. 51 ...
... the biological system that includes the pumping and channeling of blood to and from the body and lungs with heart, blood and ... potassium-sensitive cardiodysrhythmic type) Ashman phenomenon (Ashman beats) Atrial fibrillation Atrial fibrillation with rapid ...
After running a second test, however, the coroner confirmed that someone had given MacKenzie potassium chloride to induce a ... making it the third most-watched program for the channel behind Game of Thrones and Blue Bloods. "The Little Guy" has generally ...
Physical: The earthworm's burrowing creates a multitude of channels through the soil and is of great value in maintaining the ... and 11 times richer in available potassium than the surrounding upper 6 inches (150 mm) of soil. In conditions where humus is ...
CREB2 generates an inhibitory environment by increasing expression of leaky potassium channels, which helps to stabilize peak ...
... is due to absorption into human cells and production of nano-channels that obstruct vital ion channels that ferry potassium and ... permeable channels and adverse action towards mammalian cells". FEBS Journal. 279 (22): 4172-4190. doi:10.1111/febs.12010. PMID ...
The channel conductance is not higher in the presence of benzodiazepine and GABA than the conductance with the presence of only ... Further studies in animal neuropathic pain models have shown that stabilizing the Potassium Chloride Cotranspoter 2 (KCC2) at ... But if the γ2 is expressed with α1 and β2 the sensitivity is low and channel conductance is high. γ2 subunit has to be present ... GABAA PAMs increase the effect of GABA by making the channel open more frequently or for longer periods. However, they have no ...
Other bases such as potassium carbonate or cesium carbonate are occasionally used. In addition, deaerated conditions are ... "A Practical and Efficient Synthesis of the Selective Neuronal Acetylcholine-Gated Ion Channel Agonist (S)-(−)-5-Ethynyl-3-(1- ...
... and large conductance calcium-activated potassium channel (BKCa) are the two primary channels for potassium secretion. WNK1 ... WNK1 regulates potassium channels found in the cortical collecting duct (CCD) and connecting tubule (CNT). Renal outer medullar ... GABA activates the GABAA receptor which is a Cl− ion channel. Cl− ions will enter the neuron causing hyperpolarization and ... and potassium chloride cotransporter (KCC1) located within the kidney. CCCs mediate ion homeostasis and modulate blood pressure ...
Kumpf, R.; Dougherty, D. (1993). "A mechanism for ion selectivity in potassium channels: computational studies of cation-pi ... This force allows for the systems to be used as receptors and channels in supramolecular chemistry for applications in the ... medical (synthetic membranes, ion channels) and environmental fields (e.g. sensing, removal of ions from water). The first X- ...
potassium channel tetramerization domain containing 3provided by HGNC. Primary source. HGNC:HGNC:21305 See related. Ensembl: ... KCTD3 potassium channel tetramerization domain containing 3 [ Homo sapiens (human) ] Gene ID: 51133, updated on 4-Dec-2022 ... potassium channel tetramerisation domain containing 3. renal carcinoma antigen NY-REN-45. ... This gene encodes a member of the potassium channel tetramerization-domain containing (KCTD) protein family. Members of this ...
Anticonvulsants, Neuronal Potassium Channel Opener. Class Summary. Stabilizes neuronal KCNQ (Kv7) channels in the open position ... Ezogabine is a neuronal potassium channel opener that stabilizes neuronal KCNQ (Kv7) channels in the open position, increasing ... Owing to the presence of potassium channels in the bladder, there is a small risk of urinary retention. Ezogabine can cause ... Rufinamide modulates sodium channel activity, particularly prolongation of the channels inactive state. It significantly slows ...
Protein target information for Potassium channel, subfamily K, member 17 (zebrafish). Find diseases associated with this ...
... channels hyperpolarize neurons in response to activation of many different G protein-coupled receptors and thus control the ... Emerging roles for G protein-gated inwardly rectifying potassium (GIRK) channels in health and disease Nat Rev Neurosci. 2010 ... G protein-gated inwardly rectifying potassium (GIRK) channels hyperpolarize neurons in response to activation of many different ... GIRK channel function and trafficking are highly dependent on the channel subunit composition. Pharmacological investigations ...
Interestingly, this mechanism was also found to regulate the expression of another oncogenic channel (Kv3.4) as well as HERG2 ... Evidences indicate that HERG1 voltage-gated potassium channel is frequently aberrantly expressed in various cancers including ... It has been increasingly documented that ion channels and in particular potassium channels, are implicated in all steps of ... Potassium channels were originally identified in excitable cells but they are present in virtually all types of cells, where ...
FluxOR II Green Potassium Ion Channel Assay is the next-generation solution for HTS of potassium ion channel and transporter ...
Potassium voltage-gated channel subfamily B member 2 (CDRK) (Voltage-gated potassium channel subunit Kv2.2) ... Potassium voltage-gated channel subfamily B member 2 (CDRK) (Voltage-gated potassium channel subunit Kv2.2) ... Anti-Kv2.2 Potassium Channel Antibody (N372C/51). from NeuroMab Datasheet KO Validated 1 Citation ... Bulk Order Inquiry for Anti-Kv2.2 Potassium Channel Antibody ------- (please add any order requirements, including desired ...
1993) The S4-S5 loop contributes to the ion-selective pore of potassium channels. Neuron 11:739-749. ... 1995) Episodic ataxia results from voltage-dependent potassium channels with altered functions. Neuron 15:1449-1454. ... 1994) Episodic ataxia/myokymia syndrome is associated with point mutations in the human potassium channel gene, KCNA1. Nat ... 1992) Multiple subunits of a voltage-dependent potassium channel contribute to the binding site for tetraethylammonium. Neuron ...
Tags: ,animal models, ANK3, Ankyrin-G, bipolar depression, GABA, mania, potassium channel, sodium channel, ... The missing Ankyrin-G affected sodium channels (which allow for the flow of sodium ions in and out of cells) and potassium ... While mutations in the ANK3 gene may disturb sodium channels, another gene linked to depression and bipolar disorder, CACNA1C, ... affects calcium channels.. In a related study by researcher Rene Caballero-Florán and colleagues that was also presented at the ...
Selecting of format.. Clicking one of the Downlod boxes will download a file in the corresponding format with the selected data columns for the genes shown in the search result.. The copy boxes will give you a link to the file if you want to share it or save for later as a reference.. ...
Harvey, A L (1993) Neuropharmacology of potassium ion channels. Medicinal Research Reviews, 13 (1). pp. 81-104. ISSN 0198-6325 ... aminopyridines, animals, potassium channels, tacrine, biological toxins, Pharmacy and materia medica, Drug Discovery, Molecular ...
The present invention relates to novel uses for retigabine and KCNQ2/3 potassium channel openers. ... EN) The present invention relates to novel uses for retigabine and KCNQ2/3 potassium channel openers.. ... EN) NEW USES POTASSIUM CHANNEL OPENERS, SUCH AS THE TREATMENT OF EPILEPSY. ... 1. WO2001001970 - NEW USES POTASSIUM CHANNEL OPENERS, SUCH AS THE TREATMENT OF EPILEPSY ...
... protection by volatile anesthetics involves activation of cardiac adenosine triphosphate-sensitive potassium (KATP) channels. ... A possible role of the mitochondrial KATP channels was tested using a blocker of these channels, 5-hydroxydecanoate. ResultsThe ... The authors have previously shown that isoflurane enhances sensitivity of the sarcolemmal KATP channel to the opener, pinacidil ... and catalase were used to investigate whether reactive oxygen species mediate isoflurane facilitation of the channel opening by ...
Nomenclature and Molecular Relationships of Two-P Potassium Channels. Steve A. N. Goldstein, Douglas A. Bayliss, Donghee Kim, ... Nomenclature and Molecular Relationships of Two-P Potassium Channels. Steve A. N. Goldstein, Douglas A. Bayliss, Donghee Kim, ... Nomenclature and Molecular Relationships of Two-P Potassium Channels. Steve A. N. Goldstein, Douglas A. Bayliss, Donghee Kim, ... Nomenclature and Molecular Relationships of Two-P Potassium Channels Message Subject (Your Name) has forwarded a page to you ...
This application note describes the use of the IonWorks HT Platform with a voltagedependent potassium channel Kv1.5. ... Kv1.5 Potassium Channel Assay Using the IonWorks HT System. App Note / Case Study Published: December 24, 2011 ... IC50 curves for 4-AP blockade of Kv1.5 channels. The results are also repoted agreement with the results obtained using the ...
Allocryptopine and benzyltetrahydropalmatine block hERG potassium channels expressed in HEK293 cells ... Allocryptopine and benzyltetrahydropalmatine block hERG potassium channels expressed in HEK293 cells Kun Lin, Yu-qi Liu, Bin Xu ... Methods: Cultured HEK293 cells were transiently transfected with hERG channel cDNA plasmid pcDNA3.1 using Lipofectamine. The ...
... Show full item record ... BCL2-ASSOCIATED ATHANOGENE4 Regulates the KAT1 Potassium Channel and Controls Stomatal Movement. RiuNet: Institutional ... BCL2-ASSOCIATED ATHANOGENE4 Regulates the KAT1 Potassium Channel and Controls Stomatal Movement ... BCL2-ASSOCIATED ATHANOGENE4 Regulates the KAT1 Potassium Channel and Controls Stomatal Movement. PLANT PHYSIOLOGY. 181(3):1277- ...
Potassium. Calcium-activated potassium channels are a large family of potassium channels that are found throughout the central ... Potassium channel opener; Less active enantiomer of Axon 1112 €145.00 1308 (±)-BMS 204352 Potassium channel opener; racemate of ... channels include Large conductance KCa channels (KCa1.1, also known as BK channel, Slo or Slo1), a voltage-sensitive channel ... Selective activator of large-conductance Ca2+-activated potassium (BK) channels €95.00 2329 NS 19504 Potent activator of large- ...
You are here: Home / Exposures / Noble 1962 model for Physiome article / potassium_channel_model.xml ... "potassium_channel", ,variable name="i_K" private_interface="out" public_interface="out" units="uA_per_mm2"/, ,variable name="g_ ... xml version=1.0?, ,model name="potassium_channel_model" xmlns="http://www.cellml.org/cellml/1.1#" xmlns:cellml="http://www. ...
Background Adenosine triphosphate-sensitive (KATP) potassium channel opener diazoxide (DZX) maintains myocyte volume and ... Dive into the research topics of Cardioprotective benefits of adenosine triphosphate-sensitive potassium channel opener ... N2 - Background Adenosine triphosphate-sensitive (KATP) potassium channel opener diazoxide (DZX) maintains myocyte volume and ... AB - Background Adenosine triphosphate-sensitive (KATP) potassium channel opener diazoxide (DZX) maintains myocyte volume and ...
... channel (TREK) 1, TREK2, and TWIK-related arachidonic acid stimulated K+ channel (TRAAK). Except TASK2 all mentioned channels ... 2016 - The potassium channels TASK2 and TREK1 regulate functional differentiation of murine skeletal muscle cells Patchliner ... Two-pore domain potassium (K2P) channels influence basic cellular parameters such as resting membrane potential, cellular ... The Dynamite8 is a fully automated dynamic clamp add-on integrating seamlessly into an 8-channel or 4-channel Patchliner. ...
45]The widespread homology of Potassium sup + channel proteins suggests the possibility that Potassium sup + channels ... activated Potassium sup + channels (Potassium sub [Calcium] channels) at an extracellular site with a Kd of approximately 0.3 ... halothane and isoflurane reversibly activated the serotonin-sensitive Potassium channel (S channel). The S channel is a ... Halothane acts on many potassium channels, including a minimal potassium channel. Neurosci Lett 1993; 161:81-4. ...
... via the antagonistic regulation of two potassium conductances: the leak channel Sandman imposes silence during waking, whereas ... A potassium channel β-subunit couples mitochondrial electron transport to sleep. Kempf A., Song SM., Talbot CB., Miesenböck G. ... via the antagonistic regulation of two potassium conductances: the leak channel Sandman imposes silence during waking, whereas ...
We currently also lack drugs which are specific in opening or closing individual subtypes of channel. However, when more is ... actions but more information is required on their structures and on the functions of the different subtypes of channel in ... known about the structure and function of these channels and when more specific modulators of their activity are available, it ... There is a multiplicity of potassium channels in nervous tissue. These have been characterized on the basis of their ...
Use your RU credentials (u/z-number and password) to log in with SURFconext to upload a file for processing by the repository team ...
Glucose-mediated inhibition of calcium-activated potassium channels limits α-cell calcium influx and glucagon secretion ... a-Cell K s i m ., was decreased by small-conductance Caactivated K+ (SK) channel inhibitors apamin and UCL 1684. ... PANCREATIC BETA-CELLS; K-ATP CHANNELS; ENDOPLASMIC-RETICULUM; CA2+ CONCENTRATION; DELTA-CELLS; INSULIN; SOMATOSTATIN; RELEASE; ... GENERATION; CONTRIBUTE; alpha-cell; calcium handling; glucagon secretion; potassium channel. Dewey Decimal Classification:. 100 ...
Mechanism of mechanosensitive gating of the TREK-2 potassium channel. ... Mechanism of mechanosensitive gating of the TREK-2 potassium channel. Brennecke, J. T., & de Groot, B. L. (2018). Mechanism of ... of the TREK-2 potassium channel. Biophysical Journal, 114(6), 1336-1343. doi:10.1016/j.bpj.2018.01.030. ...
Twisting conformational change of the channel upon gating. The transmembrane domain of the potassium channel is formed by a ... To gain dynamic pictures of functional channel, the KcsA potassium channel upon gating were examined by the diffracted X-ray ... the channel exhibited small random fluctuations of its structure. When the channel is actively gating at acidic pH, the channel ... Crystal structure of potassium channels in closed and open states has been elucidated. ...
We thank the Japan Agency for Medical Research and Development for its financial support of this research (grant number JP19lk0201080), which is covering almost all the operational costs of this trial. Abbreviations CASPR 1contactin-associated protein 1.CIDPchronic inflammatory demyelinating polyradiculoneuropathy.CNTN1contactin-1.EFNS/PNSEuropean Federation of TCS2314 Neurological Societies/Peripheral Nerve Society.Igimmunoglobulin.INCATInflammatory Neuropathy Cause and Treatment.IVIgintravenous immunoglobulin.MuSKmuscle-specific tyrosine kinase.NF155neurofascin-155.PMDAPharmaceuticals and Medical […]. ...
  • GIRK channel function and trafficking are highly dependent on the channel subunit composition. (nih.gov)
  • To examine the relative contribution of EA subunits in forming heteromeric EA and wild-type channels, each EA subunit was made insensitive to TEA, TEA-tagged, and coexpressed with wild-type subunits. (jneurosci.org)
  • The second group of Ca 2+ activated K + channels include Large conductance KCa channels ( KCa1.1 , also known as BK channel, Slo or Slo1), a voltage-sensitive channel that binds calcium independently of calmodulin but mediated by at least three divalent cation binding sites in the cytoplasmic carboxyl domain of each channel subunit. (axonmedchem.com)
  • A potassium channel β-subunit couples mitochondrial electron transport to sleep. (ox.ac.uk)
  • Voltage-gated potassium channels are made up of 12 different subunits with several isoforms of each subunit. (reactome.org)
  • Probable potassium channel subunit. (cusabio.com)
  • One beta subunit, produced from the KCNE1 gene, binds to the channel and regulates its activity. (medlineplus.gov)
  • Ehmke H. Physiological functions of the regulatory potassium channel subunit KCNE1. (medlineplus.gov)
  • Other channel blockers include: charybdotoxin, iberiotoxin and tetraethylammonium. (guidetopharmacology.org)
  • This efflux was significantly inhibited by apamin (100 nmol/l), charybdotoxin (300 nmol/l) and alpha-dendrotoxin (100-200 nmol/l), blockers of SKCa channels, KCh channels and Kv channels respectively. (ox.ac.uk)
  • The main groups include sodium channel blockers, calcium current inhibitors, gamma-aminobutyric acid (GABA) enhancers, glutamate blockers, carbonic anhydrase inhibitors, hormones, and drugs with unknown mechanisms of action (see the image below). (medscape.com)
  • In this review, we discussed the potential effects of K ATP channel blockers when used under pathological conditions related to diabetics and cerebral ischemic stroke. (chinaphar.com)
  • Calcium channel blockers and beta blockers are poor choices because they will exacerbate hypotension. (crashingpatient.com)
  • Much acid, in potassium channel blockers inhibit clot formation of antidiabetic agents by reducing contractions. (manguerascartagenasas.com)
  • a-Cell K s i m ., was decreased by small-conductance Ca'activated K+ (SK) channel inhibitors apamin and UCL 1684. (uni-regensburg.de)
  • Mashinson, V & Hopkins, CR 2021, ' Novel inhibitors of the renal inward rectifier potassium channel of the mosquito vector Aedes aegypti ', Future Medicinal Chemistry , vol. 13, no. 22, pp. 2015-2025. (nebraska.edu)
  • Our objective was to systematically evaluate associations of 2-pore domain potassium channel gene expression and DNA methylation with triplenegative subtype in The Cancer Genome Atlas invasive breast cancer dataset. (cdc.gov)
  • Triple-negative subtype was associated with distinct 2-pore domain potassium channel expression patterns. (cdc.gov)
  • This gene encodes a member of the potassium channel tetramerization-domain containing (KCTD) protein family. (nih.gov)
  • Members of this protein family regulate the biophysical characteristics of ion channels. (nih.gov)
  • In mouse, this protein interacts with hyperpolarization-activated cyclic nucleotide-gated channel complex 3 and enhances its cell surface expression and current density. (nih.gov)
  • Up-regulation of hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) by specific interaction with K+ channel tetramerization domain-containing protein 3 (KCTD3). (nih.gov)
  • G protein-gated inwardly rectifying potassium (GIRK) channels hyperpolarize neurons in response to activation of many different G protein-coupled receptors and thus control the excitability of neurons through GIRK-mediated self-inhibition, slow synaptic potentials and volume transmission. (nih.gov)
  • Two EA subunits with the least dominant negative impact on heteromeric channels also have markedly reduced protein levels. (jneurosci.org)
  • and protein kinasing C- ϵ can modulate the channel function. (semanticscholar.org)
  • To gain further insight into the regulation of these channels, we performed a split-ubiquitin protein-protein interaction screen searching for KAT1 interactors in Arabidopsis (Arabidopsis thaliana). (upv.es)
  • Violin plots show distribution of expression levels for Small conductance calcium-activated potassium channel protein (SMED30004698) in cells (dots) of each of the 12 neoblast clusters. (stowers.org)
  • Expression of Small conductance calcium-activated potassium channel protein (SMED30004698) in the t-SNE clustered sub-lethally irradiated X1 and X2 cells. (stowers.org)
  • No channel activity observed in vitro as protein remains in the endoplasmic reticulum. (cusabio.com)
  • The M channel is formed by the association of the protein encoded by KCN2 and a related protein encoded by the KCNQ3 gene, both are integral membrane proteins. (protheragen.com)
  • The KCNE1 gene provides instructions for making a protein that regulates the activity of potassium channels. (medlineplus.gov)
  • The specific function of a potassium channel depends on its protein components and its location in the body. (medlineplus.gov)
  • The KCNE1 protein regulates a channel made up of four parts, called alpha subunits, which are produced from the KCNQ1 gene. (medlineplus.gov)
  • The KCNE1 protein is also produced in the kidneys, testes, and uterus, where it probably regulates the activity of other channels. (medlineplus.gov)
  • An altered KCNE1 protein cannot regulate the flow of potassium ions through channels in the inner ear and cardiac muscle. (medlineplus.gov)
  • K channels) the protein forms a tetramer in the membrane. (embl.de)
  • The mechanisms of benefit involve alkalinization to override the TCA s myocardial sodium channel blockade and boost protein binding so the drug doesn t cause additional problems, along with an increase in the extracellular sodium channel concentration to improve the cross-channel gradient. (crashingpatient.com)
  • The International Union of Pharmacology has put the Ca 2+ activated K + channels into one large family which can be subdivided into two functionally but genetically unrelated groups. (axonmedchem.com)
  • However, the pharmacology of these channels has not been defined. (ox.ac.uk)
  • Pharmacological evidence of calcium-activated and voltage-gated potassium channels in human platelets. (ox.ac.uk)
  • While mutations in the ANK3 gene may disturb sodium channels, another gene linked to depression and bipolar disorder, CACNA1C, affects calcium channels. (bipolarnews.org)
  • Calcium-activated potassium channels are a large family of potassium channels that are found throughout the central nervous system and in many other cell types. (axonmedchem.com)
  • These channels are voltage-insensitive and are activated by low concentrations of internal calcium (less than 1.0 microM). (axonmedchem.com)
  • Both IK and SK channels play roles in processes involving calcium-dependent signaling in both electrically excitable and nonexcitable cells. (axonmedchem.com)
  • Binding of calcium to this calmodulin results in conformational changes that are in turn responsible for channel gating. (axonmedchem.com)
  • 1] Calcium-Activated Potassium Channels: Multiple Contributions to Neuronal Function. (axonmedchem.com)
  • Nomenclature and molecular relationships of calcium-activated potassium channels. (axonmedchem.com)
  • Thiazide-induced hyperglycaemia: a role for calcium-activated potassium channels? (ru.nl)
  • 2. We have studied potassium channels in human platelets by measuring the efflux of 86Rb+ (a marker for K+) from 86Rb(+)-loaded cells, and have defined their responses to stimulation by the platelet agonist thrombin and the calcium ionophore ionomycin. (ox.ac.uk)
  • The patient required intravenous fluid replacement, potassium supplementation, and an intravenous calcium channel blocker for persistent tachycardia. (cdc.gov)
  • This domain is found in sodium, potassium, and calcium ion channels proteins. (embl.de)
  • The types of particles found consisted of alkali metals such as cesium and potassium, alkaline earth metals such as calcium and barium, and cobalt, iron, chromium, and titanium. (nhpolitician.com)
  • Spironolactone competitively binds receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. (medscape.com)
  • Receptors and Channels , 2 (4), I. (uaeu.ac.ae)
  • Many structures and processes are involved in the development of a seizure, including neurons, ion channels, receptors, glia, and inhibitory and excitatory synapses. (medscape.com)
  • This study also conclude that A.paniculata affected one of the membrane receptors, mostly ATP-dependent potassium channels (K+ATP). (who.int)
  • this review covers the efforts made toward this end by targeting the renal inward rectifier potassium channel (Kir) of the mosquito. (nebraska.edu)
  • To investigate the effects of benzyltetrahydropalmatine (BTHP) on rapidly activating component (I(Kr)), slowly activating component (I(Ks)) of delayed rectifier potassium current, inward rectifier potassium current (I(K1)), and transient outward potassium current (I(to)) in single ventricular myocytes. (unboundmedicine.com)
  • Five EA subunits formed functional homomeric channels with lower current amplitudes and altered gating properties compared with wild type. (jneurosci.org)
  • Coinjection of equal amounts of EA and wild-type mRNAs, mimicking the heterozygous condition, resulted in current amplitudes and gating properties that were intermediate between wild-type and EA homomeric channels, suggesting that heteromeric channels are formed with a mixed stoichiometry of EA and wild-type subunits. (jneurosci.org)
  • Mechanism of mechanosensitive gating of the TREK-2 potassium channel. (mpg.de)
  • To gain dynamic pictures of functional channel, the KcsA potassium channel upon gating were examined by the diffracted X-ray tracking (DXT) method. (physiology.jp)
  • When the channel is actively gating at acidic pH, the channel twisted its conformation around the pore axis. (physiology.jp)
  • This type of twisting motion may be shared by various types of ion channels upon gating. (physiology.jp)
  • H. Shimizu*, M. Iwamoto*, T. Konno*, A. Nihei***, Y. C. Sasaki** & S. Oiki*: Global Twisting Motion of Single Molecular KcsA Potassium Channel upon Gating. (physiology.jp)
  • During gating the channel molecule (un)twisted its shape, which corresponds to relaxation of the bundle, leading to opening of the permeation pathway. (physiology.jp)
  • EPR spectroscopy demonstrates that the inner gate opens maximally at low pH regardless of the magnitude of the single-channel-open probability, implying that stationary gating originates mostly from rearrangements at the selectivity filter. (edu.hk)
  • Two E71A crystal structures obtained at 2.5 Å reveal large structural excursions of the selectivity filter during ion conduction and provide a glimpse of the range of conformations available to this region of the channel during gating. (edu.hk)
  • Inwardly rectifying potassium channels (Kir) are a special subset of potassium selective ion channels which pass potassium more easily into rather than out of the cell. (umassmed.edu)
  • A1899 is a potent and selective inhibitor of the two-pore domain potassium (K2P) channel TASK-1. (bvsalud.org)
  • The delayed rectifier-type (IK)channels (Kv1.5, Kv2.1, and Kv2.2) are expressed on all neuronal somata and proximal dendrites and are also found in a wide variety of non-neuronal cells types including pancreatic islets, alveolar cells and cardiac myocytes (Hwang et al. (antibodiesinc.com)
  • Inward-rectifier channel 6.1 expression in the lung tissue also increased. (ewha.ac.kr)
  • A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA . (bvsalud.org)
  • Halothane also inhibited a smaller noninactivating channel with a linear slope conductance of approximately 40 pS. (asahq.org)
  • largeconductance Ca2+-activated K+ (BK) channel inhibitor iberiotoxin (IbTx), and intermediate-conductance Ca2+-activated K+ (BK) channel inhibitor TRAM 34. (uni-regensburg.de)
  • Investigations into the molecular basis of CHI have led to the discovery of mutations in the sulfonylurea receptor and an inwardly rectifying potassium channel. (medscape.com)
  • The missing Ankyrin-G affected sodium channels (which allow for the flow of sodium ions in and out of cells) and potassium channels. (bipolarnews.org)
  • These channels, which transport positively charged potassium atoms (ions) into and out of cells, play a key role in a cell's ability to generate and transmit electrical signals. (medlineplus.gov)
  • These channels are active in the inner ear and in heart (cardiac) muscle, where they transport potassium ions out of cells. (medlineplus.gov)
  • Cell membrane glycoproteins that are selectively permeable to potassium ions. (bvsalud.org)
  • Interestingly, this mechanism was also found to regulate the expression of another oncogenic channel (Kv3.4) as well as HERG2 and HERG3. (nature.com)
  • KCNQ3 associates with KCNQ2 to form a potassium channel to regulate neuronal excitability. (protheragen.com)
  • KCNE1 binds to the KCNQ1 pore to regulate potassium channel activity. (medlineplus.gov)
  • A single molecular KcsA channel was attached with a gold nano-crystal with a size of 20 nm and high flux X-rays were irradiated. (physiology.jp)
  • We show that in the potassium channel KcsA, proton-dependent activation is followed by an inactivation process similar to C-type inactivation, and this process is suppressed by an E71A mutation in the pore helix. (edu.hk)
  • Additionally, SPORK2 was identified as an outward-rectifying potassium channel that causes leaf-movement in the same plant. (nature.com)
  • Several pieces of evidence indicate that block of Shaker channels by the inactivation domain and synthetic (ShB) peptide involves a single blocking particle physically occluding the pore. (sussex.ac.uk)
  • K ATP channel is a hetero-octameric complex, consisting of four pore-forming Kir6.x and four regulatory sulfonylurea receptor SURx subunits. (chinaphar.com)
  • Side Fenestrations Provide an 'Anchor' for a Stable Binding of A1899 to the Pore of TASK-1 Potassium Channels. (bvsalud.org)
  • In contrast, binding of A1899 to residues of the side fenestrations might provide a physical "anchor", reflecting an energetically favorable binding mode that after pore occlusion stabilizes the closed state of the channels. (bvsalud.org)
  • Associations of two-pore domain potassium channels and triple negative breast cancer subtype in The Cancer Genome Atlas: systematic evaluation of gene expression and methylation. (cdc.gov)
  • Objectives: It is unclear whether 2-pore domain potassium channels are novel molecular markers with differential expression related to biologically aggressive triple-negative type breast tumors. (cdc.gov)
  • Methylation and expression data for all fifteen 2-pore domain potassium family genes were examined for 1040 women, and associations with triple-negative subtype (vs. luminal A) were evaluated using age/race adjusted generalized-linear models, with Bonferroni-corrected significance thresholds. (cdc.gov)
  • Voltage-gated K+ channels are important determinants of neuronal membrane excitability (Pongs, 1999). (antibodiesinc.com)
  • The IonWorks HT Instrument delivers reliable and reproducible results in the measurement of IC50 curves for 4-AP blockade of Kv1.5 channels. (technologynetworks.com)
  • Unexpectedly, most of the previously described residues that interfere with TASK-1 blockade by A1899 project their side chains toward the fenestration lumina, underlining the relevance of these structures for drug binding in K2P channels. (bvsalud.org)
  • The antiarrhythmic effects of BTHP may be mainly due to its blockade on potassium channels. (unboundmedicine.com)
  • 1. An R-wave in lead aVR greater than 3 mm, or an R/S ratio greater than 0.7, is highly suspicious for sodium channel blockade, which is the most important of the many toxicities of TCA overdose. (crashingpatient.com)
  • Blockade of cardiac fast sodium channels (leads to wide QRS, R-wave in aVR, R' wave in V1, Brugada pattern ECG, ventricular dysrhythmias. (crashingpatient.com)
  • Sodium channel blockade in the CNS leads to seizures. (crashingpatient.com)
  • Blockade of potassium channels (leads to long QT and torsade) c. (crashingpatient.com)
  • Iberiotoxin (300 nmol/l), a specific inhibitor of BKCa channels, had no effect on the thrombin-stimulated 86Rb+ efflux. (ox.ac.uk)
  • Although glibenclamide, an inhibitor of KATP channels, inhibited the thrombin-stimulated efflux, it did so only in a high concentration (20 mumol/l). 4. (ox.ac.uk)
  • Modified from Retigabine (the first approved KCNQ2/3 potassium channel activator drug but withdrawn from market in 2017), ZM-003 is a more potent KCNQ2/3 as shown in cell-based assay and is highly efficacious in a broad range of epilepsy and pain animal models. (protheragen.com)
  • These shots also include polyethylene glycol, cholesterol, a few salts (such as potassium chloride and sodium chloride), and sucrose (sugar). (nhpolitician.com)
  • BackgroundMyocardial protection by volatile anesthetics involves activation of cardiac adenosine triphosphate-sensitive potassium (KATP) channels. (semanticscholar.org)
  • The effect of isoflurane on vascular KATP channels and compare it with that on cardiac K ATP channels is examined to examine the effect of the drug on vasodilatation in animals and humans. (semanticscholar.org)
  • In the heart, the channels are involved in recharging the cardiac muscle after each heartbeat to maintain a regular rhythm. (medlineplus.gov)
  • Under pathophysiological conditions, K ATP channels play cytoprotective role in cardiac myocytes and neurons during ischemia and/ or hypoxia. (chinaphar.com)
  • Heritable arrhythmias associated with abnormal function of cardiac potassium channels. (bvsalud.org)
  • Redox modulation of vascular tone: focus of potassium channel mechanisms of dilation. (semanticscholar.org)
  • Purpose: Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. (ewha.ac.kr)
  • K ATP channels mediate insulin secretion in pancreatic islet beta cells, and controlling vascular tone. (chinaphar.com)
  • However, when more is known about the structure and function of these channels and when more specific modulators of their activity are available, it is likely that the use of such compounds may be of great value in the treatment of a variety of conditions affecting the nervous system, including epilepsy, the damage due to cerebral anoxia, neurodegenerative disorders and demyelinating disorders. (ox.ac.uk)
  • In the pathophysiology of epilepsy, KCNQ2/3 potassium channels play key role for cellular excitability in the brain. (protheragen.com)
  • The authors have previously shown that isoflurane enhances sensitivity of the sarcolemmal KATP channel to the opener, pinacidil. (semanticscholar.org)
  • Recently accumulated evidence underscoring the importance of mitochondria, reactive oxygen species, and KATP channels in cardioprotective signaling by volatile anesthetics is reviewed, and current concepts and controversies regarding the specific roles of the mitochondrial and the sarcolemmal KATp channels are addressed. (semanticscholar.org)
  • KATP channels play important roles in controlling and regulating cellular functions in response to metabolic state, which are inhibited by ATP and activated by Mg-ADP, allowing the cell to couple cellular metabolic state (ATP/ADP ratio) to electrical activity of the cell membrane. (chinaphar.com)
  • The firing of an action potential by an axon is accomplished through sodium channels. (medscape.com)
  • Taken together, these results show that the different mutations in Kv1.1 affect channel function and indicate that both dominant negative effects and haplotype insufficiency may result in the symptoms of EA. (jneurosci.org)
  • These results show that different mechanisms may underlie altered K + channel function in EA-affected individuals. (jneurosci.org)
  • The effect of ROS on potassium channel function in the vasculature is reviewed and discerning the activity of enzymes regulating production or degradation of ROS is important when assessing tissue perfusion in health and disease. (semanticscholar.org)
  • K 2P -channel expression was also detected in human muscle tissue by immunohistochemistry pointing towards possible relevance for human muscle cell maturation and function. (nanion.de)
  • Here we provide an overview of the progress made in elucidating the function of Drosophila Kir channels. (umassmed.edu)
  • This loss of channel function leads to the arrhythmia and hearing loss characteristic of Jervell and Lange-Nielsen syndrome. (medlineplus.gov)
  • He currently focuses on the function and the underlying mechanism of mechanosensitive ion channel, as well as its utilization as nanobiosensor in biomedical applications. (amj.net.au)
  • Hh fast potassium channel with function_tables. (ox.ac.uk)
  • Scientists have demonstrated that as people experience hair loss the function of potassium channels within hair follicles diminishes. (oxfordbiolabs.com)
  • This leads to disturbed muscle cell function and potassium deficiency in the blood, as potassium remains in cells in increased amounts. (nhpolitician.com)
  • Some antiepileptic drugs work by acting on combination of channels or through some unknown mechanism of action. (medscape.com)
  • Bulk Order Inquiry for Anti-Kv2.2 Potassium Channel Antibody ------- (please add any order requirements, including desired quantity, timing, etc. (antibodiesinc.com)
  • 2015), ' Distinct Cell- and Layer-Specific Expression Patterns and Independent Regulation of Kv2 Channel Subtypes in Cortical Pyramidal Neurons. . (antibodiesinc.com)
  • Previous studies have identified a potassium current in invertebrate neurons that is activated by volatile anesthetics. (asahq.org)
  • These effects were also studied at the single-channel level by patch clamping cultured neurons from the abdominal and pleural ganglia. (asahq.org)
  • In pleural sensory neurons, halothane and isoflurane increased the open probability of the outwardly rectifying serotonin-sensitive channel (S channel). (asahq.org)
  • The M channel is a slowly activating and deactivating potassium channel that plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs. (protheragen.com)
  • Channel kinetics come from garcia (2010) for olfactory receptor neurons (orn), davison et al. (ox.ac.uk)
  • Potassium supplementation should not be routinely administered with spironolactone because of the potential for the development of hyperkalemia. (medscape.com)
  • In some instances, the biophysical properties of the mutant channel have been examined, but for many the underlying molecular mechanism has not been established. (jneurosci.org)
  • We have used TASK-1 homology models based on recently crystallized K2P channels and molecular dynamics simulation to demonstrate that the highly potent TASK-1 blocker A1899 requires binding to residues located in the side fenestrations. (bvsalud.org)
  • By restoring the functionality of potassium ion channels that have broken down over time, our proprietary TRX2® formula helps to maintain normal, healthy hair on a molecular level. (oxfordbiolabs.com)
  • Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. (ewha.ac.kr)
  • In the fruitfly Drosophila, about two dozen sleep-inducing neurons3 with projections to the dorsal fan-shaped body (dFB) adjust their electrical output to sleep need4, via the antagonistic regulation of two potassium conductances: the leak channel Sandman imposes silence during waking, whereas increased A-type currents through Shaker support tonic firing during sleep5. (ox.ac.uk)
  • alpha-Cells displayed K-SLOW, currents that were dependent on Ca2+ influx through L- and P/Q-type voltage-dependent Ca2+ channels (VDCCs) as well as Ca2+ released from endoplasmic reticulum stores. (uni-regensburg.de)
  • These channels mediate a variety of cellular functions, including control of membrane resting potential, maintenance of potassium homeostasis and regulation of cellular metabolism. (umassmed.edu)
  • The purpose of the present study was to test the hypothesis that ATP-sensitive potassium channels mediate autoregulatory vasodilatation of coronary arterioles in vivo. (elsevier.com)
  • Given the existence of fifteen Kir genes in mammals, current genetic studies using mutant animals that lack a single channel may have missed many important physiological functions of these channels due to gene redundancy. (umassmed.edu)
  • It exerts a diuretic effect on the distal renal tubule to inhibit reabsorption of sodium in exchange for potassium and hydrogen. (medscape.com)
  • The development of structural analogues of capsazepine may yield compounds that could selectively inhibit HCN channels and prove useful for the treatment of neurological disorders where a role for HCN channels has been described. (nih.gov)
  • Moreover, differences in K+ channel expression patterns and densities contribute to the variations in action potential waveforms and repetitive firing patterns evident in different neuronal cell types. (antibodiesinc.com)
  • Because potassium channels are important regulators of neuronal excitability within the mammalian central nervous system, background channels such as the S channel may be responsible in part for mediating the action of volatile anesthetics. (asahq.org)
  • These data establish a mechanistic basis for the role of the selectivity filter during channel activation and inactivation. (edu.hk)
  • Growing evidence indicates that tumours tend to express splice variants or alternative transcripts of channel-encoding genes. (nature.com)
  • In some Na channel proteins the domain is repeated four times, whereas in others (e.g. (embl.de)
  • Pharmacological investigations of GIRK channels and studies in animal models suggest that GIRK activity has an important role in physiological responses, including pain perception and memory modulation. (nih.gov)
  • At physiological pH where the channel keeps its gate closed, the channel exhibited small random fluctuations of its structure. (physiology.jp)
  • This review highlights the most recent and interesting articles on the physiologic properties and functions of ATP-dependent potassium channels in the cardiovascular system and on the role of the potassium channel openers for the treatment of cardiovascular dysfunction. (semanticscholar.org)
  • In the tutorial, the Hodgkin & Huxley potassium channel is used as the example illustrating the core concepts of components and connections in CellML. (physiomeproject.org)
  • Plasma renin activity (PRA), aldosterone levels, plasma volume, and serum potassium concentrations remain essentially unchanged with nifedipine use. (medscape.com)
  • In high concentrations, barium blocks the passive potassium channels in the cell membrane. (nhpolitician.com)
  • All of the mutations occur in positions highly conserved among the voltage-dependent K + channel superfamily. (jneurosci.org)