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.
One of the two major classes of cholinergic receptors. Nicotinic receptors were originally distinguished by their preference for NICOTINE over MUSCARINE. They are generally divided into muscle-type and neuronal-type (previously ganglionic) based on pharmacology, and subunit composition of the receptors.
Cell surface proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.
A member of the NICOTINIC ACETYLCHOLINE RECEPTOR subfamily of the LIGAND-GATED ION CHANNEL family. It consists entirely of pentameric a7 subunits expressed in the CNS, autonomic nervous system, vascular system, lymphocytes and spleen.
Neurotoxic proteins from the venom of the banded or Formosan krait (Bungarus multicinctus, an elapid snake). alpha-Bungarotoxin blocks nicotinic acetylcholine receptors and has been used to isolate and study them; beta- and gamma-bungarotoxins act presynaptically causing acetylcholine release and depletion. Both alpha and beta forms have been characterized, the alpha being similar to the large, long or Type II neurotoxins from other elapid venoms.
A genus of the Torpedinidae family consisting of several species. Members of this family have powerful electric organs and are commonly called electric rays.
Vesicular amine transporter proteins that transport the neurotransmitter ACETYLCHOLINE into small SECRETORY VESICLES. Proteins of this family contain 12 transmembrane domains and exchange vesicular PROTONS for cytoplasmic acetylcholine.
One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.
Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses.
Drugs that bind to and activate nicotinic cholinergic receptors (RECEPTORS, NICOTINIC). Nicotinic agonists act at postganglionic nicotinic receptors, at neuroeffector junctions in the peripheral nervous system, and at nicotinic receptors in the central nervous system. Agents that function as neuromuscular depolarizing blocking agents are included here because they activate nicotinic receptors, although they are used clinically to block nicotinic transmission.
In about 250 species of electric fishes, modified muscle fibers forming disklike multinucleate plates arranged in stacks like batteries in series and embedded in a gelatinous matrix. A large torpedo ray may have half a million plates. Muscles in different parts of the body may be modified, i.e., the trunk and tail in the electric eel, the hyobranchial apparatus in the electric ray, and extrinsic eye muscles in the stargazers. Powerful electric organs emit pulses in brief bursts several times a second. They serve to stun prey and ward off predators. A large torpedo ray can produce of shock of more than 200 volts, capable of stunning a human. (Storer et al., General Zoology, 6th ed, p672)
An alkaloid, originally from Atropa belladonna, but found in other plants, mainly SOLANACEAE. Hyoscyamine is the 3(S)-endo isomer of atropine.
Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.
A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity.
The synapse between a neuron and a muscle.
A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.
A neuromuscular blocker and active ingredient in CURARE; plant based alkaloid of Menispermaceae.
Any drug used for its actions on cholinergic systems. Included here are agonists and antagonists, drugs that affect the life cycle of ACETYLCHOLINE, and drugs that affect the survival of cholinergic neurons. The term cholinergic agents is sometimes still used in the narrower sense of MUSCARINIC AGONISTS, although most modern texts discourage that usage.
Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.
A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.
Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.
An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.
A specific subtype of muscarinic receptor found in the lower BRAIN, the HEART and in SMOOTH MUSCLE-containing organs. Although present in smooth muscle the M2 muscarinic receptor appears not to be involved in contractile responses.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
Drugs that bind to and activate muscarinic cholinergic receptors (RECEPTORS, MUSCARINIC). Muscarinic agonists are most commonly used when it is desirable to increase smooth muscle tone, especially in the GI tract, urinary bladder and the eye. They may also be used to reduce heart rate.
A specific subtype of muscarinic receptor that has a high affinity for the drug PIRENZEPINE. It is found in the peripheral GANGLIA where it signals a variety of physiological functions such as GASTRIC ACID secretion and BRONCHOCONSTRICTION. This subtype of muscarinic receptor is also found in neuronal tissues including the CEREBRAL CORTEX and HIPPOCAMPUS where it mediates the process of MEMORY and LEARNING.
A disorder of neuromuscular transmission characterized by weakness of cranial and skeletal muscles. Autoantibodies directed against acetylcholine receptors damage the motor endplate portion of the NEUROMUSCULAR JUNCTION, impairing the transmission of impulses to skeletal muscles. Clinical manifestations may include diplopia, ptosis, and weakness of facial, bulbar, respiratory, and proximal limb muscles. The disease may remain limited to the ocular muscles. THYMOMA is commonly associated with this condition. (Adams et al., Principles of Neurology, 6th ed, p1459)
Drugs used to cause dilation of the blood vessels.
A subclass of muscarinic receptor that mediates cholinergic-induced contraction in a variety of SMOOTH MUSCLES.
Drugs that mimic the effects of parasympathetic nervous system activity. Included here are drugs that directly stimulate muscarinic receptors and drugs that potentiate cholinergic activity, usually by slowing the breakdown of acetylcholine (CHOLINESTERASE INHIBITORS). Drugs that stimulate both sympathetic and parasympathetic postganglionic neurons (GANGLIONIC STIMULANTS) are not included here.
The specialized postsynaptic region of a muscle cell. The motor endplate is immediately across the synaptic cleft from the presynaptic axon terminal. Among its anatomical specializations are junctional folds which harbor a high density of cholinergic receptors.
Contractile tissue that produces movement in animals.
A nicotinic antagonist that is well absorbed from the gastrointestinal tract and crosses the blood-brain barrier. Mecamylamine has been used as a ganglionic blocker in treating hypertension, but, like most ganglionic blockers, is more often used now as a research tool.
An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.
A C19 norditerpenoid alkaloid (DITERPENES) from the root of ACONITUM plants. It activates VOLTAGE-GATED SODIUM CHANNELS. It has been used to induce ARRHYTHMIAS in experimental animals and it has antiinflammatory and antineuralgic properties.
A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Peptide neurotoxins from the marine fish-hunting snails of the genus CONUS. They contain 13 to 29 amino acids which are strongly basic and are highly cross-linked by disulfide bonds. There are three types of conotoxins, omega-, alpha-, and mu-. OMEGA-CONOTOXINS inhibit voltage-activated entry of calcium into the presynaptic membrane and therefore the release of ACETYLCHOLINE. Alpha-conotoxins inhibit the postsynaptic acetylcholine receptor. Mu-conotoxins prevent the generation of muscle action potentials. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)
Drugs that bind to and activate cholinergic receptors.
Azocines are a class of organic compounds that are used as pharmaceuticals, particularly as vasodilators and antihypertensive agents.
Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.
A non-hydrolyzed muscarinic agonist used as a research tool.
Toxins, contained in cobra (Naja) venom that block cholinergic receptors; two specific proteins have been described, the small (short, Type I) and the large (long, Type II) which also exist in other Elapid venoms.
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.
The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
A high-affinity muscarinic antagonist commonly used as a tool in animal and tissue studies.
A protein component of the synaptic basal lamina. It has been shown to induce clustering of acetylcholine receptors on the surface of muscle fibers and other synaptic molecules in both synapse regeneration and development.
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).
Nerve fibers liberating acetylcholine at the synapse after an impulse.
Compounds containing the hexamethylenebis(trimethylammonium) cation. Members of this group frequently act as antihypertensive agents and selective ganglionic blocking agents.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
A muscarinic antagonist used to study binding characteristics of muscarinic cholinergic receptors.
Use of electric potential or currents to elicit biological responses.
A potent inhibitor of the high affinity uptake system for CHOLINE. It has less effect on the low affinity uptake system. Since choline is one of the components of ACETYLCHOLINE, treatment with hemicholinium can deplete acetylcholine from cholinergic terminals. Hemicholinium 3 is commonly used as a research tool in animal and in vitro experiments.
Dihydro analog of beta-erythroidine, which is isolated from the seeds and other plant parts of Erythrina sp. Leguminosae. It is an alkaloid with curarimimetic properties.
Drugs that bind to but do not activate CHOLINERGIC RECEPTORS, thereby blocking the actions of ACETYLCHOLINE or cholinergic agonists.
The resection or removal of the innervation of a muscle or muscle tissue.
A class of saturated compounds consisting of two rings only, having two or more atoms in common, containing at least one hetero atom, and that take the name of an open chain hydrocarbon containing the same total number of atoms. (From Riguady et al., Nomenclature of Organic Chemistry, 1979, p31)
An alkaloid from SOLANACEAE, especially DATURA and SCOPOLIA. Scopolamine and its quaternary derivatives act as antimuscarinics like ATROPINE, but may have more central nervous system effects. Among the many uses are as an anesthetic premedication, in URINARY INCONTINENCE, in MOTION SICKNESS, as an antispasmodic, and as a mydriatic and cycloplegic.
A cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike PHYSOSTIGMINE, does not cross the blood-brain barrier.
A genus of fish, in the family GYMNOTIFORMES, capable of producing an electric shock that immobilizes fish and other prey. The species Electrophorus electricus is also known as the electric eel, though it is not a true eel.
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
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)
Quinolizines are a class of organic compounds with a six-membered ring containing five nitrogen atoms, used in the development of drugs for various medical indications.
A synthetic nondepolarizing blocking drug. The actions of gallamine triethiodide are similar to those of TUBOCURARINE, but this agent blocks the cardiac vagus and may cause sinus tachycardia and, occasionally, hypertension and increased cardiac output. It should be used cautiously in patients at risk from increased heart rate but may be preferred for patients with bradycardia. (From AMA Drug Evaluations Annual, 1992, p198)
A specific subtype of muscarinic receptor found in the CORPUS STRIATUM and the LUNG. It has similar receptor binding specificities to MUSCARINIC RECEPTOR M1 and MUSCARINIC RECEPTOR M2.
Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
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 that contain the decamethylenebis(trimethyl)ammonium radical. These compounds frequently act as neuromuscular depolarizing agents.
An antimuscarinic agent that inhibits gastric secretion at lower doses than are required to affect gastrointestinal motility, salivary, central nervous system, cardiovascular, ocular, and urinary function. It promotes the healing of duodenal ulcers and due to its cytoprotective action is beneficial in the prevention of duodenal ulcer recurrence. It also potentiates the effect of other antiulcer agents such as CIMETIDINE and RANITIDINE. It is generally well tolerated by patients.
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.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Venoms produced by frogs, toads, salamanders, etc. The venom glands are usually on the skin of the back and contain cardiotoxic glycosides, cholinolytics, and a number of other bioactive materials, many of which have been characterized. The venoms have been used as arrow poisons and include bufogenin, bufotoxin, bufagin, bufotalin, histrionicotoxins, and pumiliotoxin.
A selective nicotinic cholinergic agonist used as a research tool. DMPP activates nicotinic receptors in autonomic ganglia but has little effect at the neuromuscular junction.
Cell membranes associated with synapses. Both presynaptic and postsynaptic membranes are included along with their integral or tightly associated specializations for the release or reception of transmitters.
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.
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.
The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
A 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.
Plant extracts from several species, including genera STRYCHNOS and Chondodendron, which contain TETRAHYDROISOQUINOLINES that produce PARALYSIS of skeletal muscle. These extracts are toxic and must be used with the administration of artificial respiration.
A toxic alkaloid found in Amanita muscaria (fly fungus) and other fungi of the Inocybe species. It is the first parasympathomimetic substance ever studied and causes profound parasympathetic activation that may end in convulsions and death. The specific antidote is atropine.
That phase of a muscle twitch during which a muscle returns to a resting position.
A nicotinic cholinergic antagonist often referred to as the prototypical ganglionic blocker. It is poorly absorbed from the gastrointestinal tract and does not cross the blood-brain barrier. It has been used for a variety of therapeutic purposes including hypertension but, like the other ganglionic blockers, it has been replaced by more specific drugs for most purposes, although it is widely used a research tool.
Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.
A heterogeneous group of disorders characterized by a congenital defect in neuromuscular transmission at the NEUROMUSCULAR JUNCTION. This includes presynaptic, synaptic, and postsynaptic disorders (that are not of autoimmune origin). The majority of these diseases are caused by mutations of various subunits of the nicotinic acetylcholine receptor (RECEPTORS, NICOTINIC) on the postsynaptic surface of the junction. (From Arch Neurol 1999 Feb;56(2):163-7)
A specific subtype of muscarinic receptor found in a variety of locations including the SALIVARY GLANDS and the SUBSTANTIA NIGRA and VENTRAL TEGMENTAL AREA of the BRAIN.
The rate dynamics in chemical or physical systems.
Clusters of neurons and their processes in the autonomic nervous system. In the autonomic ganglia, the preganglionic fibers from the central nervous system synapse onto the neurons whose axons are the postganglionic fibers innervating target organs. The ganglia also contain intrinsic neurons and supporting cells and preganglionic fibers passing through to other ganglia.
A technique for measuring extracellular concentrations of substances in tissues, usually in vivo, by means of a small probe equipped with a semipermeable membrane. Substances may also be introduced into the extracellular space through the membrane.
Ganglia of the parasympathetic nervous system, including the ciliary, pterygopalatine, submandibular, and otic ganglia in the cranial region and intrinsic (terminal) ganglia associated with target organs in the thorax and abdomen.
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.
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.
Cholinesterases are enzymes that break down the neurotransmitter acetylcholine, playing a crucial role in regulating nerve impulses in the body.
Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.
A family of hexahydropyridines.
Endogenously-synthesized compounds that influence biological processes not otherwise classified under ENZYMES; HORMONES or HORMONE ANTAGONISTS.
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).
Part of the arm in humans and primates extending from the ELBOW to the WRIST.
Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
Chemically stimulated aggregation of cell surface receptors, which potentiates the action of the effector cell.
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.
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.
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.
A competitive inhibitor of nitric oxide synthetase.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Elements of limited time intervals, contributing to particular results or situations.
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.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.
Neurons whose primary neurotransmitter is ACETYLCHOLINE.
An inhibitor of nitric oxide synthetase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. (Neurochem Res 1995:200(4):451-6)
A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).
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.
Drugs used to cause constriction of the blood vessels.
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.
Agents that mimic neural transmission by stimulation of the nicotinic receptors on postganglionic autonomic neurons. Drugs that indirectly augment ganglionic transmission by increasing the release or slowing the breakdown of acetylcholine or by non-nicotinic effects on postganglionic neurons are not included here nor are the nonspecific cholinergic agonists.
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
Pinched-off nerve endings and their contents of vesicles and cytoplasm together with the attached subsynaptic area of the membrane of the post-synaptic cell. They are largely artificial structures produced by fractionation after selective centrifugation of nervous tissue homogenates.
Drugs that interrupt transmission at the skeletal neuromuscular junction by causing sustained depolarization of the motor end plate. These agents are primarily used as adjuvants in surgical anesthesia to cause skeletal muscle relaxation.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
A nonapeptide messenger that is enzymatically produced from KALLIDIN in the blood where it is a potent but short-lived agent of arteriolar dilation and increased capillary permeability. Bradykinin is also released from MAST CELLS during asthma attacks, from gut walls as a gastrointestinal vasodilator, from damaged tissues as a pain signal, and may be a neurotransmitter.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
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.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
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.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
A benzazepine derived from norbelladine. It is found in GALANTHUS and other AMARYLLIDACEAE. It is a cholinesterase inhibitor that has been used to reverse the muscular effects of GALLAMINE TRIETHIODIDE and TUBOCURARINE and has been studied as a treatment for ALZHEIMER DISEASE and other central nervous system disorders.
Limbless REPTILES of the suborder Serpentes.
The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.
A piperidine botanical insecticide.
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 volatile vasodilator which relieves ANGINA PECTORIS by stimulating GUANYLATE CYCLASE and lowering cytosolic calcium. It is also sometimes used for TOCOLYSIS and explosives.
Arteries which arise from the abdominal aorta and distribute to most of the intestines.
An inhibitor of drug metabolism and CYTOCHROME P-450 ENZYME SYSTEM activity.
The neural systems which act on VASCULAR SMOOTH MUSCLE to control blood vessel diameter. The major neural control is through the sympathetic nervous system.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
Agents having as their major action the interruption of neural transmission at nicotinic receptors on postganglionic autonomic neurons. Because their actions are so broad, including blocking of sympathetic and parasympathetic systems, their therapeutic use has been largely supplanted by more specific drugs. They may still be used in the control of blood pressure in patients with acute dissecting aortic aneurysm and for the induction of hypotension in surgery.
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.
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)
One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.
An organophosphate cholinesterase inhibitor that is used as a pesticide.
Azetidines are a class of heterocyclic compounds with a five-membered ring containing three carbon atoms and two nitrogen atoms, used in the development of medications for various conditions.
The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.
Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.
A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.
An essential amino acid that is physiologically active in the L-form.
A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.
Tritium is a radioactive isotope of hydrogen used in medical applications such as radiation therapy and as a tracer in diagnostic imaging.
The action of a drug that may affect the activity, metabolism, or toxicity of another drug.
Quinuclidines are a class of psychoactive drugs that act as dopamine agonists and antagonists, and have been used in the treatment of Parkinson's disease and schizophrenia.
Established cell cultures that have the potential to propagate indefinitely.
An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.
The veins and arteries of the HEART.
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.
Drugs that interrupt transmission of nerve impulses at the skeletal neuromuscular junction. They can be of two types, competitive, stabilizing blockers (NEUROMUSCULAR NONDEPOLARIZING AGENTS) or noncompetitive, depolarizing agents (NEUROMUSCULAR DEPOLARIZING AGENTS). Both prevent acetylcholine from triggering the muscle contraction and they are used as anesthesia adjuvants, as relaxants during electroshock, in convulsive states, etc.
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.
The ability of a substrate to allow the passage of ELECTRONS.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
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 flow of BLOOD through or around an organ or region of the body.
The modification of the reactivity of ENZYMES by the binding of effectors to sites (ALLOSTERIC SITES) on the enzymes other than the substrate BINDING SITES.
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.
The nonstriated involuntary muscle tissue of blood vessels.
An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
The smallest divisions of the arteries located between the muscular arteries and the capillaries.
Sweat-producing structures that are embedded in the DERMIS. Each gland consists of a single tube, a coiled body, and a superficial duct.
One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.
The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.
Any autoimmune animal disease model used in the study of MYASTHENIA GRAVIS. Injection with purified neuromuscular junction acetylcholine receptor (AChR) (see RECEPTORS, CHOLINERGIC) components results in a myasthenic syndrome that has acute and chronic phases. The motor endplate pathology, loss of acetylcholine receptors, presence of circulating anti-AChR antibodies, and electrophysiologic changes make this condition virtually identical to human myasthenia gravis. Passive transfer of AChR antibodies or lymphocytes from afflicted animals to normals induces passive transfer experimental autoimmune myasthenia gravis. (From Joynt, Clinical Neurology, 1997, Ch 54, p3)
Spasm of the large- or medium-sized coronary arteries.
Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.
Compounds containing the PhCH= radical.
Quinoxalines are a class of heterocyclic compounds with two nitrogen atoms in a six-membered ring, which have potential medicinal applications as antimicrobial, antiviral, and anticancer agents.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.
A hallucinogen formerly used as a veterinary anesthetic, and briefly as a general anesthetic for humans. Phencyclidine is similar to KETAMINE in structure and in many of its effects. Like ketamine, it can produce a dissociative state. It exerts its pharmacological action through inhibition of NMDA receptors (RECEPTORS, N-METHYL-D-ASPARTATE). As a drug of abuse, it is known as PCP and Angel Dust.
Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
The most common inhibitory neurotransmitter in the central nervous system.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
Neurons which activate MUSCLE CELLS.
An alkaloid obtained from the betel nut (Areca catechu), fruit of a palm tree. It is an agonist at both muscarinic and nicotinic acetylcholine receptors. It is used in the form of various salts as a ganglionic stimulant, a parasympathomimetic, and a vermifuge, especially in veterinary practice. It has been used as a euphoriant in the Pacific Islands.
A slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
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.
Drugs used to specifically facilitate learning or memory, particularly to prevent the cognitive deficits associated with dementias. These drugs act by a variety of mechanisms. While no potent nootropic drugs have yet been accepted for general use, several are being actively investigated.
A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).
Venoms from snakes of the genus Naja (family Elapidae). They contain many specific proteins that have cytotoxic, hemolytic, neurotoxic, and other properties. Like other elapid venoms, they are rich in enzymes. They include cobramines and cobralysins.
The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
An acridine derivative formerly widely used as an antimalarial but superseded by chloroquine in recent years. It has also been used as an anthelmintic and in the treatment of giardiasis and malignant effusions. It is used in cell biological experiments as an inhibitor of phospholipase A2.

Inhibitory innervation of cat sphincter of Oddi. (1/8871)

1 Electrical stimulation with trains of 0.1-0.2 ms pulses of the cat isolated sphincter of Oddi inhibited the spontaneous contractile activity and lowered base-line tension considerably. A contraction usually followed the period of stimulation. 2 These inhibitory effects were prevented by tetrodotoxin 0.1-0.5 mug/ml but were not reduced by hexamethonilm, morphine, or blockade of alpha- or beta-adrenoreceptors of cholinoceptors with phenoxy-benzamine propranolol or atropine, respectively. 3 Adenosine-5'-triphosphate (ATP) and adenosine-5'-diphosphate (ADP) inhibited the spontaneous sphincter activity and caused relaxation thus mimicking the effects of the C-terminal octapeptide of cholecystokinin (C8-CCK), isoprenaline and prostaglandin E1 and E2. 4 ATP alone (greater than 100 mug/ml) or ATP (greater than 10 mug/ml) plus dipyridamole (1 mug/ml), relaxed the sphincter to the same degrees as did the field stimulation. 5 In sphincter maximally contracted by acetylcholine, the effect of stimulation was more marked than that recorded in uncontracted preparations. 6 The present findings suggest that the sphincter of Oddi receives inhibitory nerves that are neither cholinergic nor adrenergic.  (+info)

A comparison of affinity constants for muscarine-sensitive acetylcholine receptors in guinea-pig atrial pacemaker cells at 29 degrees C and in ileum at 29 degrees C and 37 degrees C. (2/8871)

1 The affinity of 17 compounds for muscarine-sensitive acetylcholine receptors in atrial pacemaker cells and ileum of the guinea-pig has been measured at 29 degrees C in Ringer-Locke solution. Measurements were also made at 37 degrees C with 7 of them. 2 Some of the compounds had much higher affinity for the receptors in the ileum than for those in the atria. For the most selective compound, 4-diphenylacetoxy-N-methylpiperidine methiodide, the difference was approximately 20-fold. The receptors in the atria are therefore different the structure from those in the ileum. 3 The effect of temperature on affinity are not the same for all the compounds, tested indicating different enthalpies and entropies of adsorption and accounting for some of the difficulty experienced in predicting the affinity of new compounds.  (+info)

Modulation of long-term synaptic depression in visual cortex by acetylcholine and norepinephrine. (3/8871)

In a slice preparation of rat visual cortex, we discovered that paired-pulse stimulation (PPS) elicits a form of homosynaptic long-term depression (LTD) in the superficial layers when carbachol (CCh) or norepinephrine (NE) is applied concurrently. PPS by itself, or CCh and NE in the absence of synaptic stimulation, produced no lasting change. The LTD induced by PPS in the presence of NE or CCh is of comparable magnitude with that obtained with prolonged low-frequency stimulation (LFS) but requires far fewer stimulation pulses (40 vs 900). The cholinergic facilitation of LTD was blocked by atropine and pirenzepine, suggesting involvement of M1 receptors. The noradrenergic facilitation of LTD was blocked by urapidil and was mimicked by methoxamine, suggesting involvement of alpha1 receptors. beta receptor agonists and antagonists were without effect. Induction of LTD by PPS was inhibited by NMDA receptor blockers (completely in the case of NE; partially in the case of CCh), suggesting that one action of the modulators is to control the gain of NMDA receptor-dependent homosynaptic LTD in visual cortex. We propose that this is a mechanism by which cholinergic and noradrenergic inputs to the neocortex modulate naturally occurring receptive field plasticity.  (+info)

Endothelial function in Marfan syndrome: selective impairment of flow-mediated vasodilation. (4/8871)

BACKGROUND: The cardiovascular complications of Marfan syndrome arise due to alterations in the structural and functional properties of fibrillin, a constituent of vascular connective tissues. Fibrillin-containing microfibrils are closely associated with arterial endothelial cells, indicating a possible functional role for fibrillin in the endothelium. Plasma concentrations of endothelial cell products are elevated in Marfan subjects, which indirectly indicates endothelial dysfunction. This study directly assessed flow- and agonist-mediated endothelium-dependent brachial artery reactivity in Marfan subjects. METHODS AND RESULTS: In 20 Marfan and 20 control subjects, brachial artery diameter, blood flow, and blood pressure were measured by ultrasonic wall tracking, Doppler ultrasound, and photoplethysmography, respectively. Measurements were taken during hand hyperemia (a stimulus for endothelium-derived nitric oxide [NO] release in the upstream brachial artery) and after sublingual administration of the endothelium-independent vasodilator nitroglycerin. In 9 Marfan and 6 control subjects, the above parameters were also assessed during intra-arterial infusions of acetylcholine and bradykinin (agonists that stimulate NO production) and NG-monomethyl-L-arginine (L-NMMA, an inhibitor of NO production). Flow-mediated responses differed markedly between Marfan and control subjects (-1.6+/-3.5% versus 6. 50+/-4.1%, respectively; P<0.0001), whereas nitroglycerin produced similar vasodilation (14.2+/-5.7% versus 15.2+/-7.8%; P=NS). Agonist-induced vasodilation to incremental intra-arterial infusions of acetylcholine and bradykinin were not significantly different between Marfan and control subjects, and intra-arterial L-NMMA produced similar reductions in brachial artery diameter in both groups. CONCLUSIONS: These data demonstrate impaired flow-mediated but preserved agonist-mediated endothelium-dependent vasodilation in Marfan subjects and suggest preservation of basal NO release. Selective loss of flow-mediated dilation suggests a role for fibrillin in endothelial cell mechanotransduction.  (+info)

Adrenoreceptors of the guinea-pig urinary bladder. (5/8871)

1 Adrenaline, noradrenaline and isoprenaline (5 mug/ml) did not affect the resting tone of the isolated urinary bladder of the guinea-pig. 2 The catecholamines (1-2 mug/ml) inhibited neuronally evoked contractions at various stimulation frequencies; the inhibition was maximum at 2 Hz and minimum at 50 Hz. Isoprenaline produced maximum inhibition. 3 Propranolol (0.5 mug/ml) completely blocked the catecholamine-induced inhibition at all the frequencies employed. The concentration-response curves of isoprenaline at 2, 10 and 50 Hz were characteristically shifted by propranolol (50 ng/ml). Phenoxybenzamine (0.2 mug/ml) was totally ineffective. 4 In some experiments adrenaline significantly raised the tone of the bladder exposed to propranolol; this effect could be blocked by phenoxybenzamine. 5 Acetylcholine-induced bladder contractions were inhibited by adrenaline (2 mug/ml); the inhibition was completely blocked by propranolol (0.5 mug/ml). 6 The results indicate the presence of an inhibitory beta-adrenoceptor and suggest the possibility of an excitatory alpha-adrenoceptor in guinea-pig urinary bladder.  (+info)

Calcium responses induced by acetylcholine in submucosal arterioles of the guinea-pig small intestine. (6/8871)

1. Calcium responses induced by brief stimulation with acetylcholine (ACh) were assessed from the fluorescence changes in fura-2 loaded submucosal arterioles of the guinea-pig small intestine. 2. Initially, 1-1.5 h after loading with fura-2 (fresh tissues), ACh increased [Ca2+]i in a concentration-dependent manner. This response diminished with time, and finally disappeared in 2-3 h (old tissues). 3. Ba2+ elevated [Ca2+]i to a similar extent in both fresh and old tissues. ACh further increased the Ba2+-elevated [Ca2+]i in fresh tissues, but reduced it in old tissues. Responses were not affected by either indomethacin or nitroarginine. 4. In fresh mesenteric arteries, mechanical removal of endothelial cells abolished the ACh-induced increase in [Ca2+]i, with no alteration of [Ca2+]i at rest and during elevation with Ba2+. 5. In the presence of indomethacin and nitroarginine, high-K+ solution elevated [Ca2+]i in both fresh and old tissues. Subsequent addition of ACh further increased [Ca2+]i in fresh tissues without changing it in old tissues. 6. Proadifen, an inhibitor of the enzyme cytochrome P450 mono-oxygenase, inhibited the ACh-induced changes in [Ca2+]i in both fresh and Ba2+-stimulated old tissues. It also inhibited the ACh-induced hyperpolarization. 7. In fresh tissues, the ACh-induced Ca2+ response was not changed by apamin, charybdotoxin (CTX), 4-aminopyridine (4-AP) or glibenclamide. In old tissues in which [Ca2+]i had previously been elevated with Ba2+, the ACh-induced Ca2+ response was inhibited by CTX but not by apamin, 4-AP or glibenclamide. 8. It is concluded that in submucosal arterioles, ACh elevates endothelial [Ca2+]i and reduces muscular [Ca2+]i, probably through the hyperpolarization of endothelial or smooth muscle membrane by activating CTX-sensitive K+ channels.  (+info)

Somatostatin induces hyperpolarization in pancreatic islet alpha cells by activating a G protein-gated K+ channel. (7/8871)

Somatostatin inhibits glucagon-secretion from pancreatic alpha cells but its underlying mechanism is unknown. In mouse alpha cells, we found that somatostatin induced prominent hyperpolarization by activating a K+ channel, which was unaffected by tolbutamide but prevented by pre-treating the cells with pertussis toxin. The K+ channel was activated by intracellular GTP (with somatostatin), GTPgammaS or Gbetagamma subunits. It was thus identified as a G protein-gated K+ (K(G)) channel. RT-PCR and immunohistochemical analyses suggested the K(G) channel to be composed of Kir3.2c and Kir3.4. This study identified a novel ionic mechanism involved in somatostatin-inhibition of glucagon-secretion from pancreatic alpha cells.  (+info)

Inhibition of endothelium-dependent hyperpolarization by endothelial prostanoids in guinea-pig coronary artery. (8/8871)

1. In smooth muscle of the circumflex coronary artery of guinea-pig, acetylcholine (ACh, 10(-6) M) produced an endothelium-dependent hyperpolarization consisting of two components. An initial component that occurs in the presence of ACh and a slow component that developed after ACh had been withdrawn. Each component of the hyperpolarization was accompanied by an increase in membrane conductance. 2. Indomethacin (5 x 10(-6) M) or diclofenac (10(-6) M), both inhibitors of cyclooxygenase, abolished only the slow hyperpolarization. The initial hyperpolarization was not inhibited by diclofenac nor by nitroarginine, an inhibitor of nitric oxide synthase. 3. Both components of the ACh-induced hyperpolarization were abolished in the presence of atropine (10(-6) M) or high-K solution ([K+]0 = 29.4 mM). 4. The interval between ACh-stimulation required to generate an initial hyperpolarization of reproducible amplitude was 20 min or greater, but it was reduced to less than 5 min after inhibiting cyclooxygenase activity. Conditioning stimulation of the artery with substance P (10(-7) M) also caused a long duration (about 20 min) inhibition of the ACh-response. 5. The amplitude of the hyperpolarization generated by Y-26763, a K+-channel opener, was reproducible within 10 min after withdrawal of ACh. 6. Exogenously applied prostacyclin (PGI2) hyperpolarized the membrane and reduced membrane resistance in concentrations over 2.8 x 10(-9)M. 7. At concentrations below threshold for hyperpolarization and when no alteration of membrane resistance occurred, PGI2 inhibited the initial component of the ACh-induced hyperpolarization. 8. It is concluded that endothelial prostanoids, possibly PGI2, have an inhibitory action on the release of endothelium-derived hyperpolarizing factor.  (+info)

Acetylcholine is a neurotransmitter that plays a crucial role in the transmission of signals between neurons in the nervous system. It is synthesized from the amino acid choline and is stored in vesicles within nerve cells. When an electrical signal reaches the end of a nerve cell, it triggers the release of acetylcholine into the synaptic cleft, the small gap between the nerve cell and the next cell it communicates with. Acetylcholine then binds to receptors on the surface of the receiving cell, causing a change in its electrical activity. Acetylcholine is involved in a wide range of bodily functions, including muscle movement, memory, and learning. It is also important for the regulation of the autonomic nervous system, which controls involuntary bodily functions such as heart rate and digestion. In the medical field, acetylcholine is used as a diagnostic tool to study the function of the nervous system, particularly in conditions such as Alzheimer's disease and myasthenia gravis. It is also used as a therapeutic agent in the treatment of certain conditions, such as glaucoma and myasthenia gravis, by increasing the activity of the affected nerves.

Receptors, Nicotinic are a type of neurotransmitter receptor found in the nervous system that are activated by the neurotransmitter acetylcholine. These receptors are involved in a variety of physiological processes, including muscle contraction, heart rate regulation, and the regulation of breathing. They are also found in the brain and are thought to play a role in learning, memory, and mood regulation. In the medical field, the study of nicotinic receptors is important for understanding the effects of nicotine, which is the primary psychoactive substance in tobacco, as well as for the development of drugs for the treatment of conditions such as Alzheimer's disease and schizophrenia.

Receptors, cholinergic are a type of protein found on the surface of cells in the body that bind to and respond to the neurotransmitter acetylcholine. These receptors play a role in many physiological processes, including muscle contraction, heart rate, and the regulation of the autonomic nervous system. They are also involved in the transmission of signals between neurons in the central nervous system and between neurons and muscles. In the medical field, cholinergic receptors are important targets for drugs used to treat a variety of conditions, including Alzheimer's disease, myasthenia gravis, and certain types of depression.

The alpha7 nicotinic acetylcholine receptor (α7nAChR) is a type of ion channel protein found on the surface of certain cells in the nervous system. It is activated by the neurotransmitter acetylcholine, which is released by nerve cells (neurons) to communicate with each other. The α7nAChR plays a role in a number of important functions in the brain and body, including learning and memory, mood regulation, and muscle movement. It is also involved in the development and progression of certain neurological disorders, such as Alzheimer's disease, Parkinson's disease, and schizophrenia. In the medical field, the α7nAChR is being studied as a potential target for the development of new treatments for these and other conditions. For example, drugs that selectively activate the α7nAChR are being investigated as potential treatments for cognitive decline and other symptoms associated with Alzheimer's disease.

Bungarotoxins are a type of neurotoxin produced by certain species of venomous snakes, such as the Indian krait (Bungarus caeruleus) and the Chinese krait (Bungarus multicinctus). These toxins are highly potent and can cause paralysis and death in humans and other animals if not treated promptly. Bungarotoxins work by binding to and blocking the action of acetylcholine, a neurotransmitter that is essential for transmitting signals between nerve cells. This leads to a disruption in the normal functioning of the nervous system, causing symptoms such as muscle weakness, paralysis, and respiratory failure. In the medical field, bungarotoxins are used as a research tool to study the effects of neurotoxins on the nervous system. They are also used in the development of antivenom treatments for snake bites, as well as in the treatment of certain medical conditions such as myasthenia gravis, a disorder that causes muscle weakness and fatigue.

Vesicular Acetylcholine Transport Proteins (VAChT) are a family of proteins that play a crucial role in the synthesis, storage, and release of the neurotransmitter acetylcholine (ACh) in the nervous system. VAChT is primarily expressed in cholinergic neurons, which are responsible for the transmission of signals in the peripheral and central nervous systems. VAChT is a type of synaptic vesicle protein that is responsible for the transport of ACh from the cytoplasm of cholinergic neurons into synaptic vesicles, which are small membrane-bound organelles that store neurotransmitters. When an action potential reaches the axon terminal of a cholinergic neuron, VAChT releases ACh into the synaptic cleft, where it can bind to receptors on the postsynaptic neuron and trigger a response. Defects in VAChT function have been linked to several neurological disorders, including Alzheimer's disease, myasthenia gravis, and some forms of muscular dystrophy. Therefore, understanding the role of VAChT in the nervous system is important for developing new treatments for these conditions.

Receptors, Muscarinic are a type of cell surface receptors that are activated by the neurotransmitter acetylcholine. They are found in various tissues throughout the body, including the heart, lungs, digestive system, and central nervous system. There are five subtypes of muscarinic receptors, designated M1 through M5, each with different properties and functions. Activation of muscarinic receptors can produce a wide range of effects, including contraction of smooth muscle, stimulation of glandular secretion, and modulation of neurotransmitter release. In the medical field, muscarinic receptors are important targets for the treatment of various conditions, including asthma, irritable bowel syndrome, and certain types of heart disease. Drugs that interact with muscarinic receptors are often referred to as muscarinic agonists or antagonists, depending on whether they stimulate or block the activity of the receptors.

Atropine is a medication that is used to treat a variety of conditions, including bradycardia (slow heart rate), poisoning by certain drugs or toxins, and certain types of eye surgery. It is also used to treat symptoms of certain medical conditions, such as motion sickness and irritable bowel syndrome. Atropine works by blocking the action of acetylcholine, a neurotransmitter that is involved in many bodily functions, including muscle contractions, heart rate, and digestion. This can cause a number of side effects, including dry mouth, blurred vision, and difficulty urinating. Atropine is available in a variety of forms, including tablets, injections, and eye drops. It is important to follow the instructions of your healthcare provider when taking atropine, as the dosage and duration of treatment will depend on the specific condition being treated.

Nicotine is a highly addictive psychoactive substance found in tobacco plants. It is a stimulant that affects the central nervous system and can produce feelings of pleasure and relaxation. In the medical field, nicotine is used as a treatment for smoking cessation, as it can help reduce cravings and withdrawal symptoms associated with quitting smoking. Nicotine is available in various forms, including patches, gum, lozenges, inhalers, and e-cigarettes. However, it is important to note that nicotine is also highly toxic and can be dangerous if not used properly. Long-term use of nicotine can lead to addiction, respiratory problems, heart disease, and other health issues.

Physostigmine is a medication that is used to treat a variety of conditions, including glaucoma, myasthenia gravis, and Alzheimer's disease. It is a natural alkaloid that is derived from the plant Physostigma venenosum, which is found in the rainforests of Southeast Asia. Physostigmine works by increasing the activity of the neurotransmitter acetylcholine in the brain and muscles, which can help to improve muscle strength and coordination, as well as improve memory and cognitive function. It is usually administered as an injection or a tablet, and it can cause side effects such as nausea, vomiting, and dizziness.

Carbachol is a medication that is used in the medical field to treat certain conditions such as glaucoma, irritable bowel syndrome, and urinary incontinence. It is a cholinergic agonist, which means that it works by stimulating the action of a neurotransmitter called acetylcholine in the body. Acetylcholine is involved in a wide range of bodily functions, including muscle contraction, digestion, and the regulation of the heart rate and blood pressure. By stimulating the action of acetylcholine, carbachol can help to relax muscles, increase the production of digestive juices, and slow down the heart rate and blood pressure. It is usually administered as an eye drop for glaucoma, as a suppository for irritable bowel syndrome, or as an injection for urinary incontinence.

Tubocurarine is a non-depolarizing neuromuscular blocker that is commonly used in anesthesia to relax muscles and facilitate intubation. It works by blocking the action of acetylcholine, a neurotransmitter that triggers muscle contractions, at the neuromuscular junction. This leads to muscle relaxation and paralysis. Tubocurarine is typically administered intravenously and its effects can last for several hours. It is often used in combination with other anesthetic agents to provide a smooth and safe surgical experience for the patient. However, it can also cause side effects such as bradycardia, hypotension, and respiratory depression, which require careful monitoring and management by healthcare professionals.

Cholinergic agents are drugs that affect the cholinergic system, which is a group of neurons and receptors that use the neurotransmitter acetylcholine to transmit signals. These agents can either increase or decrease the activity of the cholinergic system, depending on the specific drug and the receptors it targets. There are several types of cholinergic agents, including: 1. Acetylcholinesterase inhibitors: These drugs prevent the breakdown of acetylcholine, allowing it to remain in the synaptic cleft for a longer period of time and increasing its effects. Examples include donepezil, rivastigmine, and galantamine, which are used to treat Alzheimer's disease. 2. Nicotinic receptor agonists: These drugs bind to nicotinic acetylcholine receptors and activate them, leading to a variety of effects depending on the specific receptors involved. Examples include nicotine, which is used as a smoking cessation aid, and cytisine, which is being studied as a potential treatment for obesity. 3. Muscarinic receptor antagonists: These drugs block the effects of acetylcholine at muscarinic receptors, leading to a decrease in cholinergic activity. Examples include atropine and scopolamine, which are used as anticholinergics to treat conditions such as motion sickness and to reduce the risk of bleeding during surgery. Cholinergic agents are used to treat a variety of conditions, including Alzheimer's disease, Parkinson's disease, myasthenia gravis, and glaucoma. They can also be used to treat certain side effects of other medications, such as dry mouth and constipation.

Choline is a water-soluble nutrient that plays a crucial role in various bodily functions. In the medical field, choline is often used as a dietary supplement or medication to treat certain conditions. Choline is a precursor to the neurotransmitter acetylcholine, which is involved in muscle movement, memory, and learning. It is also important for the production of phospholipids, which are essential components of cell membranes. In addition to its role in brain function, choline is also important for liver health. It helps to prevent the buildup of fat in the liver and can be used to treat liver diseases such as non-alcoholic fatty liver disease (NAFLD) and cirrhosis. Choline deficiency can lead to a range of health problems, including muscle weakness, memory problems, and liver damage. It is therefore important to ensure that you are getting enough choline in your diet through foods such as eggs, meat, and soybeans, or through supplements if necessary.

Cholinesterase inhibitors are a class of drugs that are used to treat certain neurological conditions, such as Alzheimer's disease and myasthenia gravis. These drugs work by inhibiting the enzyme cholinesterase, which breaks down the neurotransmitter acetylcholine in the brain. By inhibiting this enzyme, cholinesterase inhibitors help to increase the levels of acetylcholine in the brain, which can improve cognitive function and muscle control in people with these conditions. There are several different types of cholinesterase inhibitors, including donepezil, rivastigmine, and galantamine. These drugs are usually taken orally and are generally well-tolerated, although they can cause side effects such as nausea, diarrhea, and headache.

Acetylcholinesterase (AChE) is an enzyme that is responsible for breaking down the neurotransmitter acetylcholine (ACh) in the nervous system. ACh is a chemical messenger that is used to transmit signals between nerve cells, and AChE plays a critical role in regulating the levels of ACh in the synaptic cleft, the small gap between nerve cells where signaling occurs. In the medical field, AChE is often studied in the context of diseases that affect the nervous system, such as Alzheimer's disease, myasthenia gravis, and certain types of nerve damage. In these conditions, the activity of AChE may be altered, leading to changes in the levels of ACh in the brain and other parts of the nervous system. AChE inhibitors are drugs that are used to treat certain neurological disorders by slowing down the breakdown of ACh, thereby increasing its levels in the brain. These drugs are commonly used to treat Alzheimer's disease and myasthenia gravis, among other conditions.

In the medical field, "Receptor, Muscarinic M2" refers to a type of protein receptor found on the surface of cells in the body that is activated by the neurotransmitter acetylcholine. The M2 muscarinic receptor is one of five subtypes of muscarinic receptors, which are named based on their sensitivity to the muscarinic agonist carbachol. The M2 muscarinic receptor is primarily found in the heart, smooth muscle, and glands, and plays a role in regulating a variety of physiological processes, including heart rate, bronchoconstriction, and secretion of saliva and other fluids. Activation of the M2 receptor can produce a range of effects, including relaxation of smooth muscle, slowing of the heart rate, and increased secretion of saliva and other fluids. In the context of medical research and drug development, the M2 muscarinic receptor is an important target for the treatment of a variety of conditions, including asthma, chronic obstructive pulmonary disease (COPD), and certain types of heart disease. Drugs that target the M2 receptor, such as ipratropium bromide and tiotropium bromide, are commonly used to treat these conditions by relaxing bronchial smooth muscle and reducing airway inflammation.

The Muscarinic M1 receptor is a type of protein receptor found in the cells of various organs and tissues in the body. It is a subtype of the muscarinic acetylcholine receptor family, which is activated by the neurotransmitter acetylcholine. The M1 receptor is primarily located in the central nervous system, where it plays a role in regulating various functions such as cognition, mood, and movement. It is also found in the heart, smooth muscle, and glands, where it regulates processes such as heart rate, muscle contraction, and glandular secretion. Activation of the M1 receptor can produce a range of effects, depending on the tissue and organ in which it is located. For example, activation of the M1 receptor in the heart can cause the heart to beat faster and stronger, while activation in the smooth muscle of the airways can cause bronchodilation, or widening of the airways. In the medical field, the M1 receptor is an important target for the development of drugs used to treat a variety of conditions, including asthma, Alzheimer's disease, and Parkinson's disease.

Myasthenia Gravis (MG) is a chronic autoimmune disorder that affects the neuromuscular junction, which is the point where nerve impulses meet muscle fibers. In MG, the immune system mistakenly attacks the receptors on the muscle fibers that are responsible for receiving signals from the nerves. This leads to a decrease in the number of receptors available to receive signals, resulting in muscle weakness and fatigue. The symptoms of MG can vary widely depending on the severity of the condition and the muscles affected. Common symptoms include difficulty with eye movement, drooping eyelids, double vision, difficulty swallowing, weakness in the arms and legs, and difficulty speaking or chewing. In severe cases, MG can lead to respiratory failure and other life-threatening complications. MG is typically diagnosed through a combination of physical examination, medical history, and laboratory tests, including blood tests to detect antibodies that are specific to MG. Treatment for MG typically involves medications to suppress the immune system and improve muscle function, as well as physical therapy and other supportive measures to manage symptoms and improve quality of life.

The Muscarinic M3 receptor is a type of protein receptor found in the cells of various organs and tissues in the body. It is a subtype of the muscarinic acetylcholine receptor, which is activated by the neurotransmitter acetylcholine. The M3 receptor is primarily located in the smooth muscle cells of the heart, as well as in the glands and smooth muscles of the respiratory, gastrointestinal, and urinary systems. Activation of the M3 receptor can cause a variety of physiological effects, including contraction of smooth muscle cells, secretion of glandular secretions, and changes in heart rate and blood pressure. In the medical field, the M3 receptor is an important target for the development of drugs used to treat a variety of conditions, including asthma, irritable bowel syndrome, overactive bladder, and certain types of heart disease. Drugs that target the M3 receptor are known as muscarinic M3 receptor antagonists or antagonists.

Mecamylamine is a medication that is used to treat high blood pressure and to prevent chest pain (angina) in people with heart disease. It works by relaxing blood vessels and decreasing the workload on the heart. Mecamylamine is usually taken by mouth, but it can also be given as an injection. It is not recommended for use in people with certain heart conditions, such as sick sinus syndrome or second- or third-degree heart block. Side effects of mecamylamine may include dizziness, headache, and nausea.

Choline O-Acetyltransferase (ChAT) is an enzyme that plays a crucial role in the synthesis of acetylcholine, a neurotransmitter that is involved in many important functions in the body, including muscle movement, memory, and learning. In the medical field, ChAT is often studied in relation to various neurological disorders, such as Alzheimer's disease, Parkinson's disease, and myasthenia gravis. In these conditions, the levels of ChAT may be reduced or abnormal, leading to a deficiency in acetylcholine and potentially contributing to the symptoms of the disease. ChAT is also used as a diagnostic marker for certain conditions, such as myasthenia gravis, where it can be measured in the blood or in muscle tissue. Additionally, ChAT inhibitors are being studied as potential treatments for certain neurological disorders, such as Alzheimer's disease, where they may help to increase acetylcholine levels in the brain.

Aconitine is a toxic alkaloid found in the plant species of the genus Aconitum, commonly known as wolfsbane. It is a potent neurotoxin that can cause serious health problems, including cardiac arrhythmias, respiratory failure, and death, if ingested or inhaled in sufficient quantities. In the medical field, aconitine is used as a medication to treat certain types of heart arrhythmias, such as atrial fibrillation and ventricular tachycardia. It works by blocking sodium channels in cardiac cells, which can help to stabilize the heart rhythm and prevent further arrhythmias. However, due to its toxicity, aconitine is only used in very specific medical situations under the supervision of a qualified healthcare professional. It is typically administered in a controlled and carefully monitored manner, and patients are closely monitored for any signs of adverse effects.

Nitroprusside is a medication that is used to treat high blood pressure (hypertension) and heart failure. It is a type of drug called a nitrovasodilator, which works by relaxing the blood vessels and allowing blood to flow more easily. This can help to lower blood pressure and improve the function of the heart. Nitroprusside is usually given as an intravenous (IV) injection, although it can also be given as a tablet or a liquid to swallow. It is usually used in the hospital setting, but it may also be used at home if a person's blood pressure is very high and needs to be lowered quickly. It is important to note that nitroprusside can cause side effects, including headache, dizziness, and low blood pressure. It should only be used under the supervision of a healthcare professional.

Conotoxins are a type of venomous protein produced by cone snails, a group of marine mollusks found in tropical and subtropical waters around the world. These toxins are highly specific and target certain types of ion channels and receptors in the nervous system of other animals, including humans. Conotoxins have been studied extensively for their potential therapeutic applications in the medical field, particularly in the treatment of neurological disorders such as chronic pain, epilepsy, and muscular dystrophy. They have also been used as research tools to study the function of ion channels and receptors in the nervous system. Conotoxins are typically extracted from the venom of cone snails using a combination of chemical and biological methods. Once isolated, they can be purified and characterized using various analytical techniques, such as mass spectrometry and X-ray crystallography. Overall, conotoxins hold great promise as a source of novel therapeutic agents for the treatment of a wide range of neurological and other diseases.

Cholinergic agonists are drugs that stimulate the activity of the cholinergic system, which is a group of neurons and receptors that use the neurotransmitter acetylcholine to transmit signals in the body. These drugs can be used to treat a variety of conditions, including Alzheimer's disease, myasthenia gravis, glaucoma, and urinary incontinence. There are several different types of cholinergic agonists, including muscarinic agonists, which stimulate muscarinic receptors, and nicotinic agonists, which stimulate nicotinic receptors. Muscarinic agonists are often used to treat conditions such as glaucoma, as they can help to increase the production of aqueous humor in the eye, which can help to reduce pressure inside the eye. Nicotinic agonists are often used to treat conditions such as Alzheimer's disease, as they can help to improve memory and cognitive function. Cholinergic agonists can be administered in a variety of ways, including orally, intravenously, and topically. They can also be given as injections or as eye drops. Some cholinergic agonists are available over-the-counter, while others require a prescription from a healthcare provider. It is important to follow the instructions provided by your healthcare provider when taking cholinergic agonists, as they can have side effects and may interact with other medications you are taking.

Azocines are a class of organic compounds that contain a nitrogen-nitrogen double bond (azo group) between two aromatic rings. They are commonly used as dyes and pigments, as well as in the synthesis of pharmaceuticals and other chemicals. In the medical field, azocines have been used as antimalarial agents, antitumor agents, and as inhibitors of various enzymes. For example, the azo dye methylene blue has been used as an antimalarial agent, and the azo dye proflavine has been used as an antitumor agent. Additionally, some azocines have been shown to inhibit the activity of enzymes such as tyrosinase, which is involved in the production of melanin, and topoisomerase II, which is involved in DNA replication and transcription. It is important to note that some azocines have been associated with potential health risks, including mutagenicity and carcinogenicity. Therefore, their use in medical applications must be carefully evaluated and monitored.

Oxotremorine is a medication that is used to treat Parkinson's disease and other movement disorders. It is a type of anticholinergic drug that works by blocking the action of acetylcholine, a neurotransmitter that is involved in muscle movement and other bodily functions. Oxotremorine is typically administered as a tablet or injection and is used to reduce tremors, stiffness, and other symptoms of Parkinson's disease. It can also be used to treat other conditions, such as dystonia and Huntington's disease. However, oxotremorine can cause side effects, such as dry mouth, blurred vision, and dizziness, and should be used with caution.

Cobra neurotoxin proteins are a group of proteins produced by certain species of venomous cobras, such as the Indian cobra (Naja naja) and the king cobra (Ophiophagus hannah). These proteins are highly toxic and can cause paralysis, respiratory failure, and even death in humans if not treated promptly. Cobra neurotoxin proteins primarily target the nervous system, specifically the voltage-gated sodium channels that are responsible for transmitting electrical signals in nerve cells. These toxins bind to the sodium channels and prevent them from functioning properly, leading to a disruption in the normal flow of electrical signals and ultimately causing paralysis. In the medical field, cobra neurotoxin proteins are used as research tools to study the function of voltage-gated sodium channels and to develop new treatments for neurological disorders. They are also used in the development of antivenom to treat cobra bites. However, due to their toxicity, the handling and use of cobra neurotoxin proteins must be done with extreme caution and under the supervision of trained professionals.

Quinuclidinyl Benzilate is a chemical compound that is used as a chemical weapon. It is a nerve agent that works by blocking the transmission of nerve impulses, leading to muscle paralysis and respiratory failure. It is classified as a Schedule 1 substance under the Chemical Weapons Convention and is illegal to possess or use. In the medical field, it is not used for any therapeutic purpose and exposure to it can be extremely dangerous and potentially lethal.

Agrin is a protein that plays a crucial role in the development and maintenance of the extracellular matrix in connective tissues, particularly in the formation of the basement membrane in the nervous system. It is synthesized by cells in the basement membrane, including Schwann cells and astrocytes, and is essential for the proper development and function of the peripheral nervous system. In the medical field, agrin is of particular interest in the study of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), as mutations in the agrin gene have been linked to these conditions. Additionally, agrin has been studied in the context of other neurological disorders, such as Alzheimer's disease and spinal muscular atrophy, as well as in the development of nerve injuries and repair.

Cholinergic fibers are a type of nerve fiber that release the neurotransmitter acetylcholine (ACh) at their terminals. These fibers are primarily involved in the transmission of signals within the nervous system and play a crucial role in many physiological processes, including muscle contraction, glandular secretion, and regulation of the autonomic nervous system. Cholinergic fibers can be found throughout the body, including in the central nervous system (CNS), peripheral nervous system (PNS), and enteric nervous system (ENS). In the CNS, cholinergic fibers are involved in learning, memory, and attention, as well as in the regulation of mood and behavior. In the PNS, cholinergic fibers are involved in the control of smooth muscle, cardiac muscle, and glandular secretion. In the ENS, cholinergic fibers are involved in the regulation of gut motility and secretion. Disruptions in cholinergic signaling have been implicated in a number of neurological and psychiatric disorders, including Alzheimer's disease, Parkinson's disease, and schizophrenia. As such, cholinergic fibers are an important area of research in the field of neuroscience and have potential therapeutic applications in the treatment of these disorders.

Hexamethonium compounds are a class of drugs that are used in the medical field as muscle relaxants. They work by blocking the action of acetylcholine, a neurotransmitter that triggers muscle contractions. This results in a decrease in muscle tone and relaxation of the muscles. Hexamethonium compounds are often used to treat conditions such as muscle spasms, urinary retention, and certain types of pain. They are also used as a diagnostic tool to test the function of the autonomic nervous system. However, hexamethonium compounds can have serious side effects, including dry mouth, blurred vision, dizziness, and difficulty breathing. They can also cause a condition called malignant hyperthermia, which is a potentially life-threatening reaction to certain anesthetic drugs. As a result, the use of hexamethonium compounds is generally reserved for cases where other treatments are not effective or are not available. They are also used with caution in patients with certain medical conditions, such as heart disease or respiratory problems.

N-Methylscopolamine is a medication that is used to treat certain types of muscle spasms, such as those that occur in the urinary tract or gastrointestinal tract. It is also used to treat certain types of tremors and to relax muscles during surgery. N-Methylscopolamine works by blocking the action of acetylcholine, a chemical that is involved in muscle contraction. This helps to relax the muscles and reduce spasms. It is available as a tablet, a patch, and an oral solution. Side effects of N-Methylscopolamine may include dry mouth, blurred vision, dizziness, and difficulty urinating. It is important to follow the instructions of your healthcare provider when using this medication.

Hemicholinium 3 (HC-3) is a synthetic chemical compound that is used in the medical field as a research tool to study the function of acetylcholine, a neurotransmitter that plays a crucial role in many bodily processes. HC-3 is a cholinesterase inhibitor, which means that it prevents the breakdown of acetylcholine in the body. This can lead to an accumulation of acetylcholine in the brain and other tissues, which can have a range of effects on brain function and behavior. HC-3 is often used in animal studies to investigate the effects of cholinesterase inhibitors on cognitive function, memory, and other aspects of brain function. It has also been used to study the role of acetylcholine in the development of certain neurological disorders, such as Alzheimer's disease and Parkinson's disease. However, HC-3 is not currently used as a therapeutic agent in humans, as it can have serious side effects and is not effective at treating these conditions.

Dihydro-beta-erythroidine (DHE) is a synthetic compound that is structurally similar to the natural alkaloid beta-erythroidine, which is found in the plant species "Erythroxylum coca." DHE is a potent antagonist of the alpha-4 beta-2 nicotinic acetylcholine receptor (nAChR), which is a type of ion channel that is found in the nervous system and is involved in a variety of physiological processes, including learning, memory, and mood regulation. In the medical field, DHE has been studied as a potential treatment for a variety of conditions, including smoking cessation, anxiety, and depression. It has been shown to reduce the rewarding effects of nicotine and to block the reinforcing effects of other drugs of abuse, such as cocaine and amphetamines. DHE has also been shown to have anxiolytic and antidepressant effects in animal models, although its clinical potential in these areas has not yet been fully evaluated. It is important to note that DHE is a synthetic compound and is not currently approved for use as a medication. Its use in research is limited to laboratory and preclinical studies, and it has not been evaluated for safety or efficacy in humans.

Cholinergic Antagonists are a class of drugs that block the action of acetylcholine, a neurotransmitter that plays a crucial role in various bodily functions. These drugs are used to treat a variety of conditions, including glaucoma, myasthenia gravis, and Alzheimer's disease. Cholinergic Antagonists work by binding to receptors on the surface of cells that are sensitive to acetylcholine, preventing the neurotransmitter from binding to the receptors and triggering a response. This can result in a decrease in muscle activity, pupil dilation, and other effects that are mediated by acetylcholine. There are several different types of Cholinergic Antagonists, including muscarinic antagonists, which block the action of acetylcholine at muscarinic receptors, and nicotinic antagonists, which block the action of acetylcholine at nicotinic receptors. Some examples of Cholinergic Antagonists include atropine, scopolamine, and memantine.

In the medical field, "Bicyclo Compounds, Heterocyclic" refers to a class of organic compounds that contain two rings of carbon atoms, with one or more heteroatoms (atoms other than carbon) such as nitrogen, oxygen, or sulfur, incorporated into the structure. These compounds are often used as pharmaceuticals or as intermediates in the synthesis of drugs. They can exhibit a wide range of biological activities, including analgesic, anti-inflammatory, anticonvulsant, and antitumor effects. Examples of bicyclo compounds include the anti-inflammatory drug ibuprofen and the anticonvulsant drug phenytoin.

Scopolamine hydrobromide is a medication that is used to treat motion sickness, nausea, and vomiting. It is a type of anticholinergic medication that works by blocking the action of acetylcholine, a neurotransmitter that is involved in muscle contraction and the regulation of the digestive system. Scopolamine hydrobromide is available in various forms, including tablets, patches, and injections, and is typically used to treat conditions such as motion sickness, postoperative nausea and vomiting, and morning sickness. It is important to note that scopolamine hydrobromide can cause side effects, such as dry mouth, blurred vision, and dizziness, and should only be used under the guidance of a healthcare professional.

Neostigmine is a medication that is used to treat certain muscle disorders, such as myasthenia gravis, and to reverse the effects of certain medications that cause muscle weakness, such as neuromuscular blockers used during surgery. It works by increasing the activity of a neurotransmitter called acetylcholine, which helps to improve muscle strength and coordination. Neostigmine is available in both injectable and oral forms, and is typically administered by a healthcare professional. It can cause side effects such as nausea, vomiting, diarrhea, and muscle cramps.

Quinolizines are a class of organic compounds that contain a six-membered ring with two nitrogen atoms. They are structurally related to quinolines, which have a similar ring structure but with only one nitrogen atom. Quinolizines have a wide range of biological activities and are used in the treatment of various medical conditions, including: 1. Antimalarial drugs: Quinolizines are used as antimalarial drugs, such as chloroquine and hydroxychloroquine, which are used to treat and prevent malaria. 2. Antipsychotic drugs: Quinolizines are also used as antipsychotic drugs, such as chlorpromazine and thioridazine, which are used to treat schizophrenia and other psychotic disorders. 3. Antihistamines: Quinolizines are used as antihistamines, such as astemizole and terfenadine, which are used to treat allergies and other conditions caused by histamine release. 4. Antifungal drugs: Quinolizines are used as antifungal drugs, such as ketoconazole and itraconazole, which are used to treat fungal infections. 5. Anticancer drugs: Quinolizines are also used as anticancer drugs, such as quinoline-8-carboxylic acid, which is being studied for its potential to treat various types of cancer. Overall, quinolizines have a diverse range of biological activities and are used in the treatment of various medical conditions.

Gallamine triethiodide is a medication that is used to treat muscle spasms and to relax muscles. It is also used to prevent muscle spasms during surgery. It is a type of muscle relaxant called a non-depolarizing neuromuscular blocking agent. It works by blocking the transmission of signals from the nerves to the muscles, which causes the muscles to relax. Gallamine triethiodide is usually given intravenously, and the effects of the medication usually last for a few hours. It is important to note that gallamine triethiodide can cause side effects, such as dizziness, nausea, and difficulty breathing, and it should only be used under the supervision of a healthcare professional.

The Muscarinic M4 Receptor is a type of protein receptor found in the cells of various tissues in the human body. It is a subtype of the muscarinic acetylcholine receptor family, which is activated by the neurotransmitter acetylcholine. The M4 receptor is primarily expressed in the central nervous system, particularly in the prefrontal cortex, hippocampus, and striatum. It is also found in other tissues such as the heart, smooth muscle, and glands. The M4 receptor plays a role in a variety of physiological processes, including cognition, mood regulation, and motor control. It has been implicated in the treatment of conditions such as Alzheimer's disease, schizophrenia, and Parkinson's disease. In the medical field, the M4 receptor is a potential target for the development of new drugs for the treatment of neurological and psychiatric disorders. However, more research is needed to fully understand the role of the M4 receptor in these conditions and to develop effective drugs that target it.

Nitric oxide (NO) is a colorless, odorless gas that is produced naturally in the body by various cells, including endothelial cells in the lining of blood vessels. It plays a crucial role in the regulation of blood flow and blood pressure, as well as in the immune response and neurotransmission. In the medical field, NO is often studied in relation to cardiovascular disease, as it is involved in the regulation of blood vessel dilation and constriction. It has also been implicated in the pathogenesis of various conditions, including hypertension, atherosclerosis, and heart failure. NO is also used in medical treatments, such as in the treatment of erectile dysfunction, where it is used to enhance blood flow to the penis. It is also used in the treatment of pulmonary hypertension, where it helps to relax blood vessels in the lungs and improve blood flow. Overall, NO is a critical molecule in the body that plays a vital role in many physiological processes, and its study and manipulation have important implications for the treatment of various medical conditions.

Decamethonium compounds are a class of drugs that are used as muscle relaxants. They work by blocking the action of acetylcholine, a neurotransmitter that triggers muscle contractions. Decamethonium compounds are often used to treat conditions such as muscle spasms, tetanus, and myasthenia gravis, a disorder that causes muscle weakness and fatigue. They are typically administered intravenously or intramuscularly. Decamethonium compounds can have side effects, including dizziness, nausea, and difficulty breathing, and they can also cause serious complications such as cardiac arrest and respiratory failure if not used properly.

Pirenzepine is a medication that is used to treat symptoms of peptic ulcers, such as stomach pain and heartburn. It works by blocking the action of a chemical called acetylcholine, which helps to relax the muscles in the stomach and intestines. This can help to reduce the amount of acid that is produced in the stomach, which can help to relieve symptoms of peptic ulcers. Pirenzepine is available in both tablet and capsule form and is usually taken once or twice a day, with or without food. It is important to follow the instructions of your healthcare provider when taking pirenzepine, as it can cause side effects such as dizziness, headache, and constipation.

Calcium is a chemical element with the symbol Ca and atomic number 20. It is a vital mineral for the human body and is essential for many bodily functions, including bone health, muscle function, nerve transmission, and blood clotting. In the medical field, calcium is often used to diagnose and treat conditions related to calcium deficiency or excess. For example, low levels of calcium in the blood (hypocalcemia) can cause muscle cramps, numbness, and tingling, while high levels (hypercalcemia) can lead to kidney stones, bone loss, and other complications. Calcium supplements are often prescribed to people who are at risk of developing calcium deficiency, such as older adults, vegetarians, and people with certain medical conditions. However, it is important to note that excessive calcium intake can also be harmful, and it is important to follow recommended dosages and consult with a healthcare provider before taking any supplements.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and hormone that plays a crucial role in the body's "fight or flight" response. It is produced by the adrenal glands and is also found in certain neurons in the brain and spinal cord. In the medical field, norepinephrine is often used as a medication to treat low blood pressure, shock, and heart failure. It works by constricting blood vessels and increasing heart rate, which helps to raise blood pressure and improve blood flow to vital organs. Norepinephrine is also used to treat certain types of depression, as it can help to increase feelings of alertness and energy. However, it is important to note that norepinephrine can have side effects, including rapid heartbeat, high blood pressure, and anxiety, and should only be used under the supervision of a healthcare professional.

Amphibian venoms are toxic substances produced by certain species of amphibians, such as frogs, toads, and salamanders. These venoms are typically secreted from specialized glands in the skin or from the salivary glands of the amphibian, and they can be used for a variety of purposes, including defense against predators, capturing prey, and as a means of communication with other members of the same species. Amphibian venoms can contain a wide range of toxic compounds, including peptides, proteins, and other molecules. These toxins can have a variety of effects on the body, including pain, paralysis, and even death in some cases. In the medical field, amphibian venoms are being studied for their potential therapeutic applications, such as the development of new pain medications or as a source of compounds with anti-inflammatory or anti-cancer properties. However, it is important to note that many amphibian venoms are also highly toxic and can be dangerous to humans, so they must be handled with caution and under the supervision of a trained professional.

Dimethylphenylpiperazinium iodide is a medication that is used to treat certain types of infections caused by bacteria. It is a type of antibiotic that works by stopping the growth of bacteria. It is usually given by injection into a vein or muscle. Dimethylphenylpiperazinium iodide is not effective against all types of bacteria, and it may not work for everyone. It is important to follow your healthcare provider's instructions carefully when using this medication.

Ion channels are specialized proteins embedded in the cell membrane that regulate the flow of ions across the membrane. These channels are essential for many cellular processes, including the transmission of nerve impulses, muscle contraction, and the regulation of cell volume and pH. Ion channels are selective for specific ions, such as sodium, potassium, calcium, or chloride, and they can be opened or closed by various stimuli, such as changes in voltage, ligand binding, or mechanical stress. When an ion channel opens, it creates a pore in the membrane that allows ions to flow through, either down their electrochemical gradient or against it, depending on the specific channel and the conditions. In the medical field, ion channels play important roles in many diseases and disorders, including neurological disorders such as epilepsy, muscular dystrophy, and cardiac arrhythmias, as well as metabolic disorders such as diabetes and obesity. Understanding the function and regulation of ion channels is therefore crucial for developing new treatments and therapies for these conditions.

Curare is a type of arrow poison that has been used by indigenous peoples in South America for centuries. In the medical field, curare is used as a muscle relaxant during surgery and other medical procedures. It works by blocking the action of acetylcholine, a neurotransmitter that triggers muscle contractions. Curare is typically administered intravenously or through a muscle injection, and its effects can last for several hours. While curare is a powerful muscle relaxant, it can also cause side effects such as dizziness, nausea, and difficulty breathing. As a result, it is typically used only under the supervision of a qualified medical professional.

Muscarine is a naturally occurring alkaloid that is found in certain mushrooms, such as the fly agaric (Amanita muscaria) and the death cap mushroom (Amanita phalloides). It is also found in some species of snails, particularly those in the genus Conus. In the medical field, muscarine has been studied for its potential therapeutic effects. It is a muscarinic acetylcholine receptor agonist, which means that it binds to and activates these receptors in the body. Muscarinic receptors are found in many different parts of the body, including the brain, heart, lungs, and digestive system. Muscarine has been studied for its potential use in the treatment of a variety of conditions, including Alzheimer's disease, Parkinson's disease, and glaucoma. It has also been used as a research tool to study the effects of muscarinic receptors on various physiological processes. However, it is important to note that muscarine is a potent toxin and can be dangerous if ingested in large quantities. Ingestion of muscarine-containing mushrooms can cause symptoms such as nausea, vomiting, hallucinations, and in severe cases, death. Therefore, it is important to exercise caution when handling and consuming mushrooms, and to seek medical attention immediately if you suspect that you have ingested a toxic mushroom.

Hexamethonium is a medication that is used to treat high blood pressure and to relax muscles in the urinary tract. It is a type of muscle relaxant called a ganglionic blocker, which works by blocking the transmission of signals between nerve cells in the autonomic nervous system. This can help to lower blood pressure and relax muscles in the urinary tract, making it easier to urinate. Hexamethonium is usually given as an injection, and it can cause side effects such as dizziness, nausea, and difficulty breathing. It is not recommended for use in people with certain medical conditions, such as glaucoma or a history of heart problems.

Myasthenic syndromes, congenital, also known as congenital myasthenic syndromes (CMS), are a group of rare inherited disorders that affect the neuromuscular junction, the point where nerve impulses are transmitted to muscles. These disorders are caused by mutations in genes that are involved in the production of proteins that are essential for the proper functioning of the neuromuscular junction. The symptoms of CMS can vary widely depending on the specific type of disorder and the severity of the symptoms. Common symptoms include muscle weakness, fatigue, and difficulty with movement. In some cases, the symptoms may be severe enough to affect breathing and require mechanical ventilation. There are several different types of CMS, including congenital myasthenic syndrome with muscle weakness and ptosis (drooping eyelids), congenital myasthenic syndrome with oculopharyngeal muscular dystrophy, and congenital myasthenic syndrome with limb-girdle muscular dystrophy. Treatment for CMS typically involves medications that improve the function of the neuromuscular junction, such as acetylcholinesterase inhibitors, and in some cases, surgery may be necessary to correct muscle weakness or other symptoms.

The Muscarinic M5 receptor, also known as the M5 muscarinic acetylcholine receptor, is a type of protein found on the surface of certain cells in the body. It is a subtype of the muscarinic acetylcholine receptor family, which is a group of receptors that are activated by the neurotransmitter acetylcholine. The M5 receptor is primarily found in the central nervous system, where it is involved in a variety of functions, including learning and memory, mood regulation, and the regulation of heart rate and blood pressure. It is also found in other parts of the body, including the gastrointestinal tract, where it plays a role in regulating muscle contractions and the secretion of digestive enzymes. Activation of the M5 receptor can have a variety of effects on cells, depending on the specific cell type and the context in which it is activated. For example, activation of the M5 receptor on neurons in the brain can lead to the release of other neurotransmitters, such as dopamine and serotonin, which can affect mood and behavior. Activation of the M5 receptor on cells in the gastrointestinal tract can lead to changes in muscle contractions and the secretion of digestive enzymes, which can affect digestion and other digestive functions. In the medical field, the M5 receptor is of interest because it has been implicated in a number of diseases and conditions, including Alzheimer's disease, Parkinson's disease, and irritable bowel syndrome. Drugs that target the M5 receptor are being studied as potential treatments for these conditions, although more research is needed to fully understand the role of the M5 receptor in these diseases and to develop effective therapies.

Potassium is a mineral that is essential for the proper functioning of many bodily processes. It is the most abundant positively charged ion in the body and plays a crucial role in maintaining fluid balance, regulating muscle contractions, transmitting nerve impulses, and supporting the proper functioning of the heart. In the medical field, potassium is often measured in blood tests to assess its levels and determine if they are within the normal range. Abnormal potassium levels can be caused by a variety of factors, including certain medications, kidney disease, hormonal imbalances, and certain medical conditions such as Addison's disease or hyperaldosteronism. Low levels of potassium (hypokalemia) can cause muscle weakness, cramps, and arrhythmias, while high levels (hyperkalemia) can lead to cardiac arrhythmias, muscle weakness, and even cardiac arrest. Treatment for potassium imbalances typically involves adjusting the patient's diet or administering medications to correct the imbalance.

Cholinesterases are a group of enzymes that break down the neurotransmitter acetylcholine in the body. There are two main types of cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Acetylcholinesterase is primarily found in the synaptic clefts of nerve cells, where it breaks down acetylcholine after it has transmitted a signal across the synapse. This helps to terminate the signal and prevent overstimulation of the postsynaptic neuron. Butyrylcholinesterase is found in a variety of tissues throughout the body, including the liver, kidney, and blood. It is also found in the brain, where it plays a role in the breakdown of acetylcholine and other neurotransmitters. In the medical field, cholinesterases are important because they are often used as markers of organ function and can be used to diagnose certain diseases. For example, low levels of acetylcholinesterase activity in the blood can be a sign of organ damage or dysfunction, while high levels of butyrylcholinesterase activity can be a sign of liver disease. Cholinesterase inhibitors are also used as medications to treat certain neurological conditions, such as Alzheimer's disease and myasthenia gravis.

Piperidines are a class of organic compounds that contain a six-membered ring with nitrogen atoms at positions 1 and 4. They are commonly used in the pharmaceutical industry as a building block for the synthesis of a wide range of drugs, including analgesics, anti-inflammatory agents, and antihistamines. Piperidines are also found in natural products, such as alkaloids, and have been used in traditional medicine for their various therapeutic effects. In the medical field, piperidines are often used as a starting point for the development of new drugs, as they can be easily modified to produce a wide range of pharmacological activities.

Biological factors refer to the various aspects of an individual's biology that can influence their health and disease risk. These factors can include genetics, hormones, immune system function, and other physiological processes. Genetics, for example, can play a significant role in determining an individual's susceptibility to certain diseases. Hormones, such as insulin and estrogen, can also affect an individual's health and disease risk. The immune system's ability to fight off infections and diseases can also be influenced by various biological factors. Other biological factors that can impact an individual's health include age, gender, ethnicity, and lifestyle factors such as diet and exercise. Understanding these biological factors can help healthcare providers develop personalized treatment plans and identify individuals who may be at higher risk for certain diseases.

Pyridines are a class of heterocyclic aromatic compounds that contain a six-membered ring with one nitrogen atom and five carbon atoms. They are commonly used in the medical field as precursors for the synthesis of various drugs and as ligands in metal complexes that have potential therapeutic applications. Some examples of drugs that contain pyridine rings include the antihistamine loratadine, the antipsychotic drug chlorpromazine, and the anti-inflammatory drug ibuprofen. Pyridines are also used as chelating agents to remove heavy metals from the body, and as corrosion inhibitors in the manufacturing of metal products.

In the medical field, a protein subunit refers to a smaller, functional unit of a larger protein complex. Proteins are made up of chains of amino acids, and these chains can fold into complex three-dimensional structures that perform a wide range of functions in the body. Protein subunits are often formed when two or more protein chains come together to form a larger complex. These subunits can be identical or different, and they can interact with each other in various ways to perform specific functions. For example, the protein hemoglobin, which carries oxygen in red blood cells, is made up of four subunits: two alpha chains and two beta chains. Each of these subunits has a specific structure and function, and they work together to form a functional hemoglobin molecule. In the medical field, understanding the structure and function of protein subunits is important for developing treatments for a wide range of diseases and conditions, including cancer, neurological disorders, and infectious diseases.

Tetrodotoxin (TTX) is a potent neurotoxin that is produced by certain species of marine animals, including pufferfish, cone snails, and some species of sea slugs. TTX is a colorless, odorless, and tasteless compound that is highly toxic to humans and other animals. In the medical field, TTX is primarily used as a research tool to study the function of voltage-gated sodium channels, which are essential for the transmission of nerve impulses. TTX blocks these channels, leading to a loss of electrical activity in nerve cells and muscles. TTX has also been used in the treatment of certain medical conditions, such as chronic pain and epilepsy. However, its use in humans is limited due to its toxicity and the difficulty in administering it safely. In addition to its medical uses, TTX has also been used as a pesticide and a tool for controlling invasive species. However, its use as a pesticide is controversial due to its potential toxicity to non-target organisms and its persistence in the environment.

Omega-N-Methylarginine (L-NMMA) is a synthetic compound that is structurally similar to the amino acid L-arginine. L-arginine is an important precursor for the production of nitric oxide (NO), a molecule that plays a crucial role in regulating blood flow and blood pressure. L-NMMA inhibits the production of NO by competing with L-arginine for the enzyme that catalyzes the conversion of L-arginine to NO. As a result, L-NMMA can reduce NO levels in the body, leading to vasoconstriction (narrowing of blood vessels) and an increase in blood pressure. L-NMMA has been used in research studies to investigate the role of NO in various physiological and pathophysiological processes, including cardiovascular disease, hypertension, and erectile dysfunction. However, it is not currently used as a therapeutic agent in clinical practice.

In the medical field, "Cells, Cultured" refers to cells that have been grown and maintained in a controlled environment outside of their natural biological context, typically in a laboratory setting. This process is known as cell culture and involves the isolation of cells from a tissue or organism, followed by their growth and proliferation in a nutrient-rich medium. Cultured cells can be derived from a variety of sources, including human or animal tissues, and can be used for a wide range of applications in medicine and research. For example, cultured cells can be used to study the behavior and function of specific cell types, to develop new drugs and therapies, and to test the safety and efficacy of medical products. Cultured cells can be grown in various types of containers, such as flasks or Petri dishes, and can be maintained at different temperatures and humidity levels to optimize their growth and survival. The medium used to culture cells typically contains a combination of nutrients, growth factors, and other substances that support cell growth and proliferation. Overall, the use of cultured cells has revolutionized medical research and has led to many important discoveries and advancements in the field of medicine.

Action potentials are electrical signals that are generated by neurons in the nervous system. They are responsible for transmitting information throughout the body and are the basis of all neural communication. When a neuron is at rest, it has a negative electrical charge inside the cell and a positive charge outside the cell. When a stimulus is received by the neuron, it causes the membrane around the cell to become more permeable to sodium ions. This allows sodium ions to flow into the cell, causing the membrane potential to become more positive. This change in membrane potential is called depolarization. Once the membrane potential reaches a certain threshold, an action potential is generated. This is a rapid and brief change in the membrane potential that travels down the length of the neuron. The action potential is characterized by a rapid rise in membrane potential, followed by a rapid fall, and then a return to the resting membrane potential. Action potentials are essential for the proper functioning of the nervous system. They allow neurons to communicate with each other and transmit information throughout the body. They are also involved in a variety of important physiological processes, including muscle contraction, hormone release, and sensory perception.

Cholinergic neurons are a type of nerve cell that release the neurotransmitter acetylcholine (ACh) at their synapses. These neurons are found throughout the nervous system, including the brain, spinal cord, and peripheral nervous system. Cholinergic neurons play important roles in many physiological processes, including muscle contraction, learning and memory, and regulation of the autonomic nervous system. They are also involved in the pathophysiology of several neurological and psychiatric disorders, such as Alzheimer's disease, Parkinson's disease, and schizophrenia. In the peripheral nervous system, cholinergic neurons are primarily responsible for controlling muscle movement and regulating the autonomic nervous system's response to various stimuli. In the central nervous system, cholinergic neurons are involved in a wide range of cognitive functions, including attention, learning, and memory. Overall, cholinergic neurons are an important component of the nervous system and play a critical role in many physiological and pathological processes.

Nitroarginine is a medication that is used to treat high blood pressure and chest pain (angina). It works by relaxing blood vessels, which allows blood to flow more easily and reduces the workload on the heart. Nitroarginine is available in various forms, including tablets, sprays, and ointments. It is usually taken as needed, but it can also be taken regularly to prevent chest pain. Nitroarginine is generally safe and well-tolerated, but it can cause side effects such as headache, dizziness, and flushing. It is important to follow the instructions of your healthcare provider when taking nitroarginine and to let them know if you experience any side effects.

Methacholine compounds are a class of drugs that are used to test the function of the bronchial muscles in the lungs. They work by stimulating the muscarinic receptors in the airways, which can cause the muscles to contract and narrow the airways. This can be useful in diagnosing conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases that involve inflammation or narrowing of the airways. Methacholine compounds are typically administered as a nebulized solution or as an aerosol, and the response to the drug is measured by observing changes in lung function, such as changes in lung volume or air flow.

In the medical field, an amino acid sequence refers to the linear order of amino acids in a protein molecule. Proteins are made up of chains of amino acids, and the specific sequence of these amino acids determines the protein's structure and function. The amino acid sequence is determined by the genetic code, which is a set of rules that specifies how the sequence of nucleotides in DNA is translated into the sequence of amino acids in a protein. Each amino acid is represented by a three-letter code, and the sequence of these codes is the amino acid sequence of the protein. The amino acid sequence is important because it determines the protein's three-dimensional structure, which in turn determines its function. Small changes in the amino acid sequence can have significant effects on the protein's structure and function, and this can lead to diseases or disorders. For example, mutations in the amino acid sequence of a protein involved in blood clotting can lead to bleeding disorders.

Serotonin is a neurotransmitter, a chemical messenger that transmits signals between nerve cells in the brain and throughout the body. It plays a crucial role in regulating mood, appetite, sleep, and other bodily functions. In the medical field, serotonin is often studied in relation to mental health conditions such as depression, anxiety, and obsessive-compulsive disorder (OCD). Low levels of serotonin have been linked to these conditions, and medications such as selective serotonin reuptake inhibitors (SSRIs) are often prescribed to increase serotonin levels in the brain and improve symptoms. Serotonin is also involved in the regulation of pain perception, blood pressure, and other bodily functions. Imbalances in serotonin levels have been implicated in a variety of medical conditions, including migraines, fibromyalgia, and irritable bowel syndrome (IBS).

Histamine is a chemical substance that is produced by certain cells in the body, including immune cells and cells in the digestive system. It plays a role in a variety of physiological processes, including the contraction of smooth muscles, the dilation of blood vessels, and the stimulation of nerve endings. In the medical field, histamine is often used as a diagnostic tool to help identify conditions such as allergies, asthma, and certain types of infections. It is also used as a treatment for certain conditions, such as allergic reactions and certain types of digestive disorders.

In the medical field, binding sites refer to specific locations on the surface of a protein molecule where a ligand (a molecule that binds to the protein) can attach. These binding sites are often formed by a specific arrangement of amino acids within the protein, and they are critical for the protein's function. Binding sites can be found on a wide range of proteins, including enzymes, receptors, and transporters. When a ligand binds to a protein's binding site, it can cause a conformational change in the protein, which can alter its activity or function. For example, a hormone may bind to a receptor protein, triggering a signaling cascade that leads to a specific cellular response. Understanding the structure and function of binding sites is important in many areas of medicine, including drug discovery and development, as well as the study of diseases caused by mutations in proteins that affect their binding sites. By targeting specific binding sites on proteins, researchers can develop drugs that modulate protein activity and potentially treat a wide range of diseases.

Bradykinin is a peptide hormone that plays a role in the regulation of blood pressure, inflammation, and pain. It is produced in the body by the breakdown of larger proteins called kinins, which are released from blood vessels and other tissues in response to injury or inflammation. Bradykinin acts on various types of cells in the body, including blood vessels, smooth muscle cells, and nerve cells, to cause a range of physiological effects. In the blood vessels, bradykinin causes them to dilate, or widen, which can lead to a drop in blood pressure. It also increases the permeability of blood vessels, allowing fluid and other substances to leak out and cause swelling. In addition to its effects on blood vessels, bradykinin is also involved in the body's inflammatory response. It stimulates the release of other inflammatory mediators, such as prostaglandins and leukotrienes, which can cause redness, swelling, and pain. Overall, bradykinin plays an important role in the body's response to injury and inflammation, and its activity is tightly regulated by various enzymes and other factors in the body.

In the medical field, "binding, competitive" refers to a type of interaction between a ligand (a molecule that binds to a receptor) and a receptor. Competitive binding occurs when two or more ligands can bind to the same receptor, but they do so in a way that limits the maximum amount of ligand that can bind to the receptor at any given time. In other words, when a ligand binds to a receptor, it competes with other ligands that may also be trying to bind to the same receptor. The binding of one ligand can prevent or reduce the binding of other ligands, depending on the relative affinities of the ligands for the receptor. Competitive binding is an important concept in pharmacology, as it helps to explain how drugs can interact with receptors in the body and how their effects can be influenced by other drugs or substances that may also be present. It is also important in the study of biological systems, where it can help to explain how molecules interact with each other in complex biological networks.

In the medical field, "cats" typically refers to Felis catus, which is the scientific name for the domestic cat. Cats are commonly kept as pets and are known for their agility, playful behavior, and affectionate nature. In veterinary medicine, cats are commonly treated for a variety of health conditions, including respiratory infections, urinary tract infections, gastrointestinal issues, and dental problems. Cats can also be used in medical research to study various diseases and conditions, such as cancer, heart disease, and neurological disorders. In some cases, the term "cats" may also refer to a group of animals used in medical research or testing. For example, cats may be used to study the effects of certain drugs or treatments on the immune system or to test new vaccines.

Quaternary ammonium compounds (QACs) are a class of cationic compounds that consist of a central nitrogen atom bonded to four alkyl or aryl groups, with one of the alkyl groups replaced by a positively charged ammonium ion. In the medical field, QACs are commonly used as disinfectants, antiseptics, and preservatives due to their broad-spectrum antimicrobial activity against bacteria, viruses, fungi, and algae. QACs work by disrupting the cell membrane of microorganisms, leading to cell lysis and death. They are particularly effective against Gram-positive bacteria, which have a thick peptidoglycan layer that can be penetrated by the positively charged ammonium ion. QACs are also effective against enveloped viruses, such as influenza and herpes, by disrupting the viral envelope. QACs are used in a variety of medical applications, including as disinfectants for surfaces and equipment, antiseptics for skin and wound care, and preservatives for pharmaceuticals and medical devices. However, QACs can also be toxic to humans and other animals if ingested or inhaled in high concentrations. Therefore, proper handling and use of QACs are essential to minimize the risk of adverse effects.

Galantamine is a medication used to treat mild to moderate symptoms of Alzheimer's disease. It works by increasing the levels of certain chemicals in the brain that are important for memory and learning. Galantamine is available as a tablet, capsule, and liquid to take by mouth. It is usually taken once or twice a day, with or without food. Common side effects of galantamine include nausea, vomiting, diarrhea, dizziness, and headache. It may also cause low blood pressure, especially when taken on an empty stomach.

Anabasine is a toxic alkaloid found in the tobacco plant (Nicotiana tabacum) and some other species of the Nicotiana genus. It is one of the main alkaloids responsible for the addictive properties of tobacco and is also responsible for many of the harmful effects of smoking, including respiratory problems, heart disease, and cancer. In the medical field, anabasine is not typically used as a therapeutic agent. However, it has been studied for its potential as an anti-inflammatory and anti-cancer agent. Some studies have suggested that anabasine may have anti-inflammatory effects by inhibiting the production of inflammatory cytokines, and it has also been shown to have anti-cancer effects by inhibiting the growth of cancer cells in vitro. Despite these potential benefits, anabasine is still considered a toxic substance and is not recommended for use as a therapeutic agent. The use of tobacco products, which contain anabasine and other harmful chemicals, is strongly discouraged by medical professionals due to the serious health risks associated with smoking.

In the medical field, the brain is the most complex and vital organ in the human body. It is responsible for controlling and coordinating all bodily functions, including movement, sensation, thought, emotion, and memory. The brain is located in the skull and is protected by the skull bones and cerebrospinal fluid. The brain is composed of billions of nerve cells, or neurons, which communicate with each other through electrical and chemical signals. These neurons are organized into different regions of the brain, each with its own specific functions. The brain is also divided into two hemispheres, the left and right, which are connected by a bundle of nerve fibers called the corpus callosum. Damage to the brain can result in a wide range of neurological disorders, including stroke, traumatic brain injury, Alzheimer's disease, Parkinson's disease, and epilepsy. Treatment for brain disorders often involves medications, surgery, and rehabilitation therapies to help restore function and improve quality of life.

Nitroglycerin is a powerful vasodilator medication that is used to treat angina pectoris (chest pain caused by reduced blood flow to the heart muscle) and to prevent heart attacks. It works by relaxing the smooth muscles in the blood vessels, particularly those that supply blood to the heart, which increases blood flow and reduces the workload on the heart. Nitroglycerin is usually administered as a sublingual tablet or spray, which is placed under the tongue or sprayed into the mouth. It is absorbed quickly into the bloodstream and begins to work within a few minutes. The effects of nitroglycerin are short-lived, lasting only a few minutes to an hour, and the medication must be taken as needed to relieve symptoms. While nitroglycerin is a highly effective medication for treating angina, it can cause side effects such as headache, dizziness, and low blood pressure. It is also contraindicated in patients with certain medical conditions, such as uncontrolled high blood pressure or severe heart failure.

Proadifen is a medication that was previously used to treat high blood pressure and to prevent blood clots. It is a type of medication called a "prostaglandin F2α receptor antagonist," which works by blocking the action of prostaglandin F2α, a hormone that can cause blood vessels to narrow and blood pressure to rise. Proadifen is no longer used for these purposes due to concerns about its safety and effectiveness. It has been replaced by other medications that are considered to be safer and more effective.

Potassium chloride is a medication used to treat low potassium levels in the blood (hypokalemia). It is also used to treat certain heart rhythm problems and to help manage certain types of heart failure. Potassium chloride is available as a tablet, oral solution, and injection. It is usually taken by mouth, but can also be given intravenously (into a vein) or by injection into a muscle. Potassium chloride is a salt that contains potassium, which is an important mineral that helps regulate the heartbeat and maintain proper muscle and nerve function. It is important to follow the instructions of your healthcare provider when taking potassium chloride, as high levels of potassium in the blood can be dangerous.

The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds and encloses the cell. It is composed of a phospholipid bilayer, which consists of two layers of phospholipid molecules arranged tail-to-tail. The hydrophobic tails of the phospholipids face inward, while the hydrophilic heads face outward, forming a barrier that separates the inside of the cell from the outside environment. The cell membrane also contains various proteins, including channels, receptors, and transporters, which allow the cell to communicate with its environment and regulate the movement of substances in and out of the cell. In addition, the cell membrane is studded with cholesterol molecules, which help to maintain the fluidity and stability of the membrane. The cell membrane plays a crucial role in maintaining the integrity and function of the cell, and it is involved in a wide range of cellular processes, including cell signaling, cell adhesion, and cell division.

Alkaloids are a diverse group of naturally occurring organic compounds that are derived from plants and have a basic or alkaline nature. They are often found in the leaves, seeds, bark, and roots of plants and are known for their bitter taste and pharmacological properties. In the medical field, alkaloids have been used for centuries as traditional remedies for a variety of ailments, including pain relief, fever reduction, and digestive disorders. Many alkaloids have also been isolated and synthesized for use in modern medicine, particularly in the treatment of cancer, infections, and neurological disorders. Some well-known examples of alkaloids include caffeine, nicotine, morphine, codeine, and quinine. These compounds have a wide range of effects on the body, including stimulating the central nervous system, reducing pain and inflammation, and affecting heart rate and blood pressure. However, it is important to note that many alkaloids can also be toxic in high doses and can cause side effects such as nausea, vomiting, and dizziness. Therefore, the use of alkaloids in medicine is typically closely monitored and regulated by healthcare professionals.

Nitric oxide synthase (NOS) is an enzyme that plays a crucial role in the production of nitric oxide (NO) in the body. There are three main types of NOS: endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS). eNOS is primarily found in the endothelial cells that line blood vessels and is responsible for producing NO in response to various stimuli, such as shear stress, hormones, and neurotransmitters. NO produced by eNOS helps to relax blood vessels and improve blood flow, which is important for maintaining cardiovascular health. nNOS is found in neurons and is involved in neurotransmission and synaptic plasticity. iNOS is induced in response to inflammation and is involved in the production of NO in immune cells and other tissues. Abnormal regulation of NOS activity has been implicated in a variety of diseases, including cardiovascular disease, neurodegenerative disorders, and cancer. Therefore, understanding the mechanisms that regulate NOS activity is an important area of research in the medical field.

Paraoxon is a chemical compound that is commonly used as an insecticide and acaricide. It is also used as a nerve agent in chemical warfare. In the medical field, paraoxon is primarily used as a treatment for organophosphate poisoning, which is caused by exposure to insecticides or nerve agents that contain organophosphates. Paraoxon works by inhibiting the enzyme acetylcholinesterase, which is responsible for breaking down the neurotransmitter acetylcholine in the nervous system. When acetylcholinesterase is inhibited, acetylcholine builds up in the nervous system, leading to overstimulation and potentially causing symptoms such as muscle twitching, difficulty breathing, and seizures. Paraoxon is typically administered as an antidote to reverse the effects of organophosphate poisoning and prevent further damage to the nervous system.

Azetidines are a class of organic compounds that contain a five-membered ring with three carbon atoms and two nitrogen atoms. They are often used as intermediates in the synthesis of other compounds and have a variety of applications in the pharmaceutical industry. Some azetidines have been found to have analgesic, anti-inflammatory, and anti-anxiety properties, and have been studied as potential treatments for conditions such as pain, inflammation, and anxiety disorders. However, more research is needed to fully understand the potential therapeutic uses of azetidines and to develop safe and effective drugs based on this chemical structure.

The thoracic aorta is the largest artery in the human body, located in the chest region. It is responsible for carrying oxygenated blood from the heart to the rest of the body, specifically to the head, neck, arms, and upper torso. The thoracic aorta begins at the base of the heart and extends up to the diaphragm, where it becomes the abdominal aorta. The thoracic aorta is divided into three main sections: the ascending aorta, the aortic arch, and the descending aorta. The ascending aorta is the portion of the aorta that ascends from the heart to the aortic arch. The aortic arch is the curved portion of the aorta that arches over the top of the heart and connects the ascending aorta to the descending aorta. The descending aorta is the portion of the aorta that descends from the aortic arch to the diaphragm. The thoracic aorta is surrounded by a layer of connective tissue called the adventitia, which provides support and protection to the aorta. The aorta is also surrounded by the pericardium, a sac-like structure that surrounds the heart and helps to protect it from injury. The thoracic aorta is an important part of the circulatory system and plays a critical role in maintaining blood flow to the body's vital organs.

NG-Nitroarginine Methyl Ester (L-NAME) is a drug that is used in the medical field to study the effects of nitric oxide (NO) on various physiological processes. NO is a naturally occurring gas that plays a role in regulating blood pressure, blood flow, and the immune system. L-NAME is an inhibitor of the enzyme that produces NO, and it is often used to block the effects of NO in experiments. L-NAME is typically administered orally or intravenously, and it can cause a number of side effects, including headache, dizziness, and nausea. It is not recommended for use in pregnant women or individuals with certain medical conditions, such as liver or kidney disease.

Arginine is an amino acid that plays a crucial role in various physiological processes in the human body. It is an essential amino acid, meaning that it cannot be synthesized by the body and must be obtained through the diet. In the medical field, arginine is used to treat a variety of conditions, including: 1. Erectile dysfunction: Arginine is a precursor to nitric oxide, which helps to relax blood vessels and improve blood flow to the penis, leading to improved sexual function. 2. Cardiovascular disease: Arginine has been shown to improve blood flow and reduce the risk of cardiovascular disease by lowering blood pressure and improving the function of the endothelium, the inner lining of blood vessels. 3. Wound healing: Arginine is involved in the production of collagen, a protein that is essential for wound healing. 4. Immune function: Arginine is involved in the production of antibodies and other immune system components, making it important for maintaining a healthy immune system. 5. Cancer: Arginine has been shown to have anti-cancer properties and may help to slow the growth of tumors. However, it is important to note that the use of arginine as a supplement is not without risks, and it is important to consult with a healthcare provider before taking any supplements.

Indomethacin is a nonsteroidal anti-inflammatory drug (NSAID) that is commonly used to relieve pain, reduce inflammation, and lower fever. It works by blocking the production of prostaglandins, which are chemicals that cause pain, inflammation, and fever. Indomethacin is available in various forms, including tablets, capsules, and suppositories. It is often prescribed for conditions such as arthritis, menstrual cramps, and headaches. It can also be used to treat gout, kidney stones, and other inflammatory conditions. However, indomethacin can have side effects, including stomach pain, nausea, vomiting, and diarrhea. It can also increase the risk of bleeding and ulcers in the stomach and intestines. Therefore, it is important to use indomethacin only as directed by a healthcare provider and to report any side effects immediately.

Tritium is a radioactive isotope of hydrogen with the atomic number 3 and the symbol T. It is a beta emitter with a half-life of approximately 12.3 years. In the medical field, tritium is used in a variety of applications, including: 1. Medical imaging: Tritium is used in nuclear medicine to label molecules and track their movement within the body. For example, tritium can be used to label antibodies, which can then be injected into the body to track the movement of specific cells or tissues. 2. Radiation therapy: Tritium is used in radiation therapy to treat certain types of cancer. It is typically combined with other isotopes, such as carbon-14 or phosphorus-32, to create a radioactive tracer that can be injected into the body and targeted to specific areas of cancerous tissue. 3. Research: Tritium is also used in research to study the behavior of molecules and cells. For example, tritium can be used to label DNA, which can then be used to study the process of DNA replication and repair. It is important to note that tritium is a highly radioactive isotope and requires careful handling to minimize the risk of exposure to radiation.

Quinuclidines are a class of organic compounds that contain a quinuclidine ring, which is a six-membered ring with four nitrogen atoms and two carbon atoms. They are structurally related to the amphetamines and have been used as stimulants and nootropics. Some quinuclidines, such as pyrovalerone, have also been used as analgesics and anticonvulsants. In the medical field, quinuclidines are not commonly used and their therapeutic potential is not well established.

In the medical field, a cell line refers to a group of cells that have been derived from a single parent cell and have the ability to divide and grow indefinitely in culture. These cells are typically grown in a laboratory setting and are used for research purposes, such as studying the effects of drugs or investigating the underlying mechanisms of diseases. Cell lines are often derived from cancerous cells, as these cells tend to divide and grow more rapidly than normal cells. However, they can also be derived from normal cells, such as fibroblasts or epithelial cells. Cell lines are characterized by their unique genetic makeup, which can be used to identify them and compare them to other cell lines. Because cell lines can be grown in large quantities and are relatively easy to maintain, they are a valuable tool in medical research. They allow researchers to study the effects of drugs and other treatments on specific cell types, and to investigate the underlying mechanisms of diseases at the cellular level.

Phenylephrine is a medication that is used to treat nasal congestion and other symptoms of the common cold. It is a sympathomimetic drug that works by narrowing the blood vessels in the nasal passages, which helps to reduce swelling and congestion. Phenylephrine is available over-the-counter in a variety of forms, including nasal sprays, tablets, and liquids. It is also sometimes used to treat low blood pressure and to constrict blood vessels in the eyes, such as in the treatment of glaucoma. However, phenylephrine should not be used by people with certain medical conditions, such as high blood pressure, heart disease, or glaucoma, as it can worsen these conditions. It is also not recommended for use in children under the age of six, as it can cause serious side effects.

Coronary vessels, also known as coronary arteries, are blood vessels that supply oxygen-rich blood to the heart muscle. There are two main coronary arteries, the left coronary artery and the right coronary artery, which branch off from the aorta and travel through the heart muscle to supply blood to the heart's various chambers and valves. The coronary arteries are responsible for delivering oxygen and nutrients to the heart muscle, which is essential for its proper function. If the coronary arteries become narrowed or blocked due to atherosclerosis (the buildup of plaque), it can lead to a condition called coronary artery disease (CAD), which can cause chest pain, heart attack, and other serious cardiovascular problems. In some cases, coronary artery disease can be treated with medications, lifestyle changes, or procedures such as angioplasty or coronary artery bypass surgery. It is important to maintain a healthy lifestyle, including regular exercise, a balanced diet, and not smoking, to reduce the risk of developing coronary artery disease and other cardiovascular problems.

In the medical field, macromolecular substances refer to large molecules that are composed of repeating units, such as proteins, carbohydrates, lipids, and nucleic acids. These molecules are essential for many biological processes, including cell signaling, metabolism, and structural support. Macromolecular substances are typically composed of thousands or even millions of atoms, and they can range in size from a few nanometers to several micrometers. They are often found in the form of fibers, sheets, or other complex structures, and they can be found in a variety of biological tissues and fluids. Examples of macromolecular substances in the medical field include: - Proteins: These are large molecules composed of amino acids that are involved in a wide range of biological functions, including enzyme catalysis, structural support, and immune response. - Carbohydrates: These are molecules composed of carbon, hydrogen, and oxygen atoms that are involved in energy storage, cell signaling, and structural support. - Lipids: These are molecules composed of fatty acids and glycerol that are involved in energy storage, cell membrane structure, and signaling. - Nucleic acids: These are molecules composed of nucleotides that are involved in genetic information storage and transfer. Macromolecular substances are important for many medical applications, including drug delivery, tissue engineering, and gene therapy. Understanding the structure and function of these molecules is essential for developing new treatments and therapies for a wide range of diseases and conditions.

Allosteric regulation is a mechanism by which the activity of a protein or enzyme is modulated by the binding of a molecule to a site other than the active site. This binding can either activate or inhibit the protein's activity, depending on the specific molecule and the protein's structure. In the context of medical research, allosteric regulation is important because it plays a key role in many biological processes, including signal transduction, metabolism, and gene expression. Allosteric modulators, which are molecules that bind to allosteric sites on proteins, are being studied as potential therapeutic agents for a variety of diseases, including cancer, neurological disorders, and cardiovascular diseases. For example, some drugs that are used to treat high blood pressure work by binding to allosteric sites on enzymes that regulate blood pressure, leading to changes in the activity of these enzymes and ultimately lowering blood pressure. Similarly, some drugs that are used to treat epilepsy work by binding to allosteric sites on ion channels, leading to changes in the flow of ions across the cell membrane and preventing seizures. Overall, allosteric regulation is a complex and important mechanism that plays a key role in many biological processes and is an active area of research in the medical field.

Substance P is a neuropeptide that is involved in the transmission of pain signals in the nervous system. It is a small protein that is produced by sensory neurons in the peripheral nervous system and is released into the spinal cord and brain when these neurons are activated by noxious stimuli such as injury or inflammation. Substance P acts on specific receptors on nerve cells in the spinal cord and brain, triggering the release of other neurotransmitters and hormones that contribute to the perception of pain. It is also involved in other physiological processes, such as regulating blood pressure and heart rate. In the medical field, substance P is often studied in the context of pain management and the development of new pain medications. It is also used as a diagnostic tool in certain conditions, such as inflammatory bowel disease and irritable bowel syndrome, where it may be present in higher levels in the body.

In the medical field, a chick embryo refers to a fertilized egg of a chicken that has been incubated for a certain period of time, typically between 4 and 21 days, until it has developed into an embryo. Chick embryos are commonly used in scientific research as a model system for studying developmental biology, genetics, and other areas of biology. They are particularly useful for studying the early stages of development, as they can be easily manipulated and observed under a microscope. Chick embryos are also used in some medical treatments, such as in the development of new drugs and therapies.

Arterioles are small blood vessels that branch off from arteries and carry oxygenated blood to the capillaries, which are the smallest blood vessels in the body. They are responsible for regulating blood flow and pressure within the microcirculation, which is the network of blood vessels that supply blood to individual tissues and organs. Arterioles have a diameter of approximately 100-300 micrometers and are lined with smooth muscle cells that can contract or relax to change the diameter of the vessel. This allows for the regulation of blood flow and pressure in response to changes in the body's needs, such as during exercise or in response to changes in blood pressure. Arterioles also play a role in the exchange of nutrients, oxygen, and waste products between the blood and the surrounding tissues. They are an important part of the cardiovascular system and any dysfunction or disease affecting the arterioles can have significant consequences for overall health and wellbeing.

Dopamine is a neurotransmitter that plays a crucial role in the brain's reward and pleasure centers. It is also involved in regulating movement, motivation, and emotional responses. In the medical field, dopamine is often used to treat conditions such as Parkinson's disease, which is characterized by a lack of dopamine in the brain. It can also be used to treat high blood pressure, as well as to manage symptoms of depression and schizophrenia. Dopamine is typically administered through injections or intravenous infusions, although it can also be taken orally in some cases.

The cerebral cortex is the outermost layer of the brain, responsible for many of the higher functions of the nervous system, including perception, thought, memory, and consciousness. It is composed of two hemispheres, each of which is divided into four lobes: the frontal, parietal, temporal, and occipital lobes. The cerebral cortex is responsible for processing sensory information from the body and the environment, as well as generating motor commands to control movement. It is also involved in complex cognitive processes such as language, decision-making, and problem-solving. Damage to the cerebral cortex can result in a range of neurological and cognitive disorders, including dementia, aphasia, and apraxia.

Myasthenia Gravis, Autoimmune, Experimental refers to a specific type of experimental treatment for Myasthenia Gravis, an autoimmune disorder that causes muscle weakness and fatigue. This experimental treatment involves the use of an autoimmune therapy, which is designed to target and destroy the immune cells that are responsible for attacking the nerve-muscle junctions in the body. The goal of this treatment is to reduce the severity of the autoimmune response and improve muscle strength and function in individuals with Myasthenia Gravis. This experimental treatment is still being studied and is not yet widely available.

Coronary vasospasm is a condition in which the coronary arteries, which supply blood to the heart muscle, suddenly narrow or spasm. This can cause a temporary reduction in blood flow to the heart, which can lead to chest pain or angina. In severe cases, coronary vasospasm can cause a complete blockage of the coronary artery, leading to a heart attack. The exact cause of coronary vasospasm is not fully understood, but it is thought to be related to the constriction of the smooth muscle cells in the walls of the coronary arteries. Risk factors for coronary vasospasm include smoking, high blood pressure, and a family history of the condition. Treatment for coronary vasospasm typically involves medications to relax the smooth muscle cells in the coronary arteries and improve blood flow to the heart. In some cases, more invasive procedures such as angioplasty or coronary artery bypass surgery may be necessary.

Benzylidene compounds are a class of organic compounds that contain a benzene ring with a double bond between two carbon atoms that are bonded to a hydrogen atom and an alkyl group. These compounds are often used in the medical field as intermediates in the synthesis of various drugs and other chemical compounds. They are also used as dyes, pigments, and as stabilizers in the production of plastics and other materials. Some examples of benzylidene compounds include benzaldehyde, benzyl acetate, and benzylamine.

Quinoxalines are a class of heterocyclic compounds that contain two nitrogen atoms in a six-membered ring. They are often used as intermediates in the synthesis of other compounds, such as pharmaceuticals and agrochemicals. In the medical field, quinoxalines have been studied for their potential use as antiviral, antifungal, and antiparasitic agents. Some quinoxalines have also been shown to have anti-inflammatory and analgesic properties, and are being investigated as potential treatments for a variety of conditions, including cancer, Alzheimer's disease, and Parkinson's disease. However, more research is needed to fully understand the potential therapeutic applications of quinoxalines.

In the medical field, "Anura" refers to a group of amphibians known as frogs and toads. Anura is a taxonomic order that includes over 6,000 species of frogs and toads found worldwide. These animals are characterized by their moist skin, long hind legs for jumping, and a lack of a tail in adulthood. Frogs and toads play important roles in many ecosystems as predators, prey, and as indicators of environmental health. They are also commonly used in scientific research and as pets.

Phencyclidine (PCP) is a synthetic drug that was originally developed as an anesthetic in the 1950s. However, it was later found to have potent hallucinogenic and dissociative effects, leading to its use as a recreational drug. In the medical field, PCP is not currently used as an anesthetic or for any other medical purpose. Instead, it is primarily used in research settings to study the effects of hallucinogens on the brain and behavior. It is also sometimes used in veterinary medicine to anesthetize animals. However, due to its potential for abuse and serious side effects, PCP is a controlled substance and its use is tightly regulated by law.

Isoproterenol is a synthetic beta-adrenergic agonist that is used in the medical field as a medication. It is a drug that mimics the effects of adrenaline (epinephrine) and can be used to treat a variety of conditions, including asthma, heart failure, and bradycardia (a slow heart rate). Isoproterenol works by binding to beta-adrenergic receptors on the surface of cells, which triggers a cascade of events that can lead to increased heart rate, relaxation of smooth muscle, and dilation of blood vessels. This can help to improve blood flow and oxygen delivery to the body's tissues, and can also help to reduce inflammation and bronchoconstriction (narrowing of the airways). Isoproterenol is available in a variety of forms, including tablets, inhalers, and intravenous solutions. It is typically administered as a short-acting medication, although longer-acting formulations are also available. Side effects of isoproterenol can include tremors, palpitations, and increased heart rate, and the drug may interact with other medications that affect the heart or blood vessels.

Catecholamines are a group of neurotransmitters that are produced by the adrenal glands and certain neurons in the brain. They include norepinephrine (also known as noradrenaline), epinephrine (also known as adrenaline), and dopamine. Catecholamines play a crucial role in the body's "fight or flight" response, which is triggered in response to stress or danger. They are released by the adrenal glands in response to stress, and by certain neurons in the brain in response to certain stimuli. Norepinephrine and epinephrine are primarily responsible for the physical effects of the fight or flight response, such as increased heart rate, blood pressure, and respiration. Dopamine, on the other hand, is primarily responsible for the psychological effects of the response, such as increased alertness and focus. Catecholamines are also involved in a number of other physiological processes, including the regulation of blood sugar levels, the control of blood vessel diameter, and the regulation of mood and motivation. They are often used as medications to treat a variety of conditions, including hypertension, heart disease, and depression.

Gamma-Aminobutyric Acid (GABA) is a neurotransmitter that plays a crucial role in the central nervous system. It is a non-protein amino acid that is synthesized from glutamate in the brain and spinal cord. GABA acts as an inhibitory neurotransmitter, meaning that it reduces the activity of neurons and helps to calm and relax the brain. In the medical field, GABA is often used as a treatment for anxiety disorders, insomnia, and epilepsy. It is available as a dietary supplement and can also be prescribed by a doctor in the form of medication. GABA supplements are believed to help reduce feelings of anxiety and promote relaxation by increasing the levels of GABA in the brain. However, more research is needed to fully understand the effects of GABA on the human body and to determine the most effective ways to use it as a treatment.

Arecoline is a naturally occurring alkaloid found in the areca nut, which is the seed of the Areca catechu palm tree. It is also found in some other plants, such as the opium poppy and the castor oil plant. Arecoline is a stimulant that can affect the central nervous system, and it has been used in traditional medicine for a variety of purposes, including as a treatment for digestive disorders and as a remedy for toothaches. In the medical field, arecoline is sometimes used as a diagnostic tool to help identify certain types of cancer, such as head and neck cancer. However, it is important to note that arecoline can be toxic in high doses and can cause serious side effects, including addiction, liver damage, and respiratory problems. As a result, the use of arecoline in medicine is generally limited and closely monitored.

Pilocarpine is a medication that is used to treat glaucoma, a condition that can lead to vision loss and blindness. It is also used to treat symptoms of dry eye, such as burning, itching, and redness. Pilocarpine works by increasing the production of tears, which helps to keep the eyes lubricated and reduce dryness. It is available in both eye drops and oral tablets. Pilocarpine can cause side effects such as blurred vision, eye irritation, and increased saliva production. It is important to follow the instructions of your healthcare provider when using pilocarpine and to report any side effects to them.

Procaine is a local anesthetic medication that is commonly used to numb a specific area of the body during medical procedures. It works by blocking the transmission of pain signals from nerve endings to the brain. Procaine is usually administered as a solution that is injected into the skin or a mucous membrane, such as the mouth or throat. It is also sometimes used as a topical cream or ointment to numb the skin. Procaine is a type of amide local anesthetic, which means that it is derived from an amino acid and has a similar structure to other local anesthetics such as lidocaine and benzocaine. It is generally considered to be safe and effective when used as directed, but like all medications, it can cause side effects in some people.

Cobra venoms are toxic substances produced by cobras, a group of venomous snakes found in various parts of the world. These venoms contain a complex mixture of proteins, enzymes, and other molecules that can cause a range of physiological effects in humans and other animals. The effects of cobra venom can vary depending on the species of cobra, the dose of venom injected, and the individual's health status. Some common effects of cobra venom include pain, swelling, and muscle spasms at the site of the bite, as well as more systemic effects such as nausea, vomiting, dizziness, and difficulty breathing. In the medical field, cobra venom is studied for its potential therapeutic uses, such as in the development of new drugs for pain management, anti-inflammatory treatments, and cancer therapies. However, cobra venom is also a significant health hazard, and bites from venomous cobras can be life-threatening if not treated promptly and appropriately. Treatment typically involves antivenom therapy, which is designed to neutralize the venom and prevent its harmful effects on the body.

Blood pressure is the force exerted by the blood against the walls of the blood vessels as the heart pumps blood through the body. It is measured in millimeters of mercury (mmHg) and is typically expressed as two numbers: systolic pressure (the pressure when the heart beats) and diastolic pressure (the pressure when the heart is at rest between beats). Normal blood pressure is considered to be below 120/80 mmHg, while high blood pressure (hypertension) is defined as a systolic pressure of 140 mmHg or higher and/or a diastolic pressure of 90 mmHg or higher. High blood pressure is a major risk factor for heart disease, stroke, and other health problems.

Quinacrine is an antimalarial drug that was first synthesized in the early 20th century. It is a synthetic antimalarial agent that is effective against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum, the parasite that causes the most severe form of malaria. Quinacrine is a yellow-orange crystalline powder that is insoluble in water but soluble in organic solvents. It is usually administered orally as a tablet or as a suspension in water. Quinacrine works by inhibiting the growth and reproduction of the Plasmodium parasite in the red blood cells of the host. It does this by interfering with the parasite's ability to synthesize heme, a vital component of hemoglobin, which is necessary for the survival of the parasite. Quinacrine has also been used to treat other parasitic infections, such as leishmaniasis and schistosomiasis. However, its use has been limited due to its side effects, which include nausea, vomiting, diarrhea, and skin rashes. Additionally, quinacrine has been associated with an increased risk of liver damage and has been banned in some countries due to its potential carcinogenic effects.

In the medical field, "chickens" typically refers to the domesticated bird species Gallus gallus domesticus. Chickens are commonly raised for their meat, eggs, and feathers, and are also used in research and as pets. In veterinary medicine, chickens can be treated for a variety of health conditions, including diseases such as avian influenza, Newcastle disease, and fowl pox. They may also require treatment for injuries or trauma, such as broken bones or cuts. In human medicine, chickens are not typically used as a source of treatment or therapy. However, some research has been conducted using chicken cells or proteins as models for human diseases or as potential sources of vaccines or other medical interventions.

In the medical field, an allosteric site is a binding site on a protein molecule that is distinct from the primary binding site, or active site, where a substrate or ligand binds to the protein to initiate a specific biological activity. Allosteric sites are located on the surface of the protein and can be activated or inhibited by the binding of a molecule, called an allosteric effector, which does not directly bind to the active site. When an allosteric effector binds to an allosteric site on a protein, it can cause a conformational change in the protein that affects the protein's ability to bind to its substrate or ligand at the active site. This can either enhance or inhibit the protein's activity, depending on the specific protein and allosteric effector involved. Allosteric sites are important in many biological processes, including signal transduction, metabolism, and gene expression. They are also an important target for the development of drugs, as drugs that bind to allosteric sites can modulate the activity of a protein without directly competing with the protein's natural substrate or ligand.

Receptors, drug, in the medical field refer to specific proteins or molecules on the surface or inside cells that bind to and respond to drugs or other molecules. These receptors play a crucial role in the body's response to drugs and are the target of many medications. When a drug binds to a receptor, it can activate or inhibit the receptor's function, leading to changes in cellular signaling and ultimately resulting in a therapeutic effect. There are many different types of drug receptors, including ion channels, G-protein coupled receptors, and enzyme-linked receptors, and each type of receptor has a specific role in the body's response to drugs. Understanding the properties and functions of drug receptors is essential for the development of effective and safe medications.

Propylbenzilylcholine mustard (PBCM) is a chemical compound that is used as a vesicant, or blister agent, in military and industrial applications. It is a type of mustard gas, which is a toxic chemical warfare agent that is classified as a vesicant because it causes severe skin and eye irritation, as well as blistering of the skin and mucous membranes. In the medical field, PBCM is not used as a therapeutic agent and is not approved for use in humans. It is a highly toxic substance that can cause serious harm to human health if it is ingested, inhaled, or absorbed through the skin. In the event of exposure to PBCM, it is important to seek medical attention immediately to prevent further harm and to receive appropriate treatment.

In the medical field, diamines refer to a class of organic compounds that contain two amine groups (-NH2) attached to a carbon atom. Diamines are often used as intermediates in the synthesis of other compounds, such as antibiotics and antifungal agents. They can also be found naturally in the body and play a role in various biological processes, such as the regulation of blood pressure and the maintenance of healthy skin. Some examples of diamines include putrescine, cadaverine, and spermidine.

In the medical field, arteries are blood vessels that carry oxygenated blood away from the heart to the rest of the body. They are typically thick-walled and muscular, and their walls are lined with smooth muscle and elastic tissue that helps to maintain their shape and elasticity. There are three main types of arteries: 1. Ascending aorta: This is the largest artery in the body, and it carries oxygenated blood from the heart to the rest of the body. 2. Descending aorta: This artery carries oxygenated blood from the ascending aorta to the abdomen and lower extremities. 3. Coronary arteries: These arteries supply oxygenated blood to the heart muscle. Arteries are an essential part of the circulatory system, and any damage or blockage to them can lead to serious health problems, including heart attack and stroke.

Protoveratrines are a group of alkaloids that are found in certain plants, including Veratrum species (such as Veratrum viride and Veratrum album). These alkaloids have a variety of biological activities, including anti-inflammatory, analgesic, and antispasmodic effects. They have also been shown to have potential therapeutic applications in the treatment of a variety of conditions, including pain, inflammation, and muscle spasms. However, due to their potential toxicity, the use of protoveratrines in medicine is generally limited to research and experimental settings.

The aorta is the largest artery in the human body, responsible for carrying oxygenated blood from the heart to the rest of the body. It is located in the chest and abdomen and is divided into three main sections: the ascending aorta, the aortic arch, and the descending aorta. The ascending aorta begins at the base of the heart and travels upward to the aortic arch. The aortic arch is a curved section of the aorta that arches over the top of the heart and connects to the descending aorta. The descending aorta continues downward from the aortic arch and eventually branches into smaller arteries that supply blood to the lower body. The aorta is an essential part of the circulatory system and plays a critical role in maintaining overall health and wellbeing. Any damage or disease affecting the aorta can have serious consequences, including heart attack, stroke, and even death.

Levamisole is an anthelmintic medication that is used to treat various types of parasitic infections, including roundworms, hookworms, and whipworms. It works by paralyzing the muscles of the parasites, allowing the body's immune system to remove them. In addition to its use as an anthelmintic, levamisole has also been used in the treatment of certain types of cancer, such as colorectal cancer. It is thought to work by stimulating the immune system to attack cancer cells. However, levamisole has also been associated with serious side effects, including fever, nausea, vomiting, abdominal pain, and skin rash. In some cases, it can cause more serious side effects, such as blood disorders, liver damage, and even death. As a result, the use of levamisole for cancer treatment has been largely discontinued in many countries, and it is now primarily used as an anthelmintic.

Mollusk venoms are toxic substances produced by mollusks, such as snails, clams, octopuses, and squids. These venoms can cause a range of symptoms in humans, including pain, swelling, and in severe cases, respiratory failure, paralysis, and death. Mollusk venoms are composed of a complex mixture of proteins, peptides, and other molecules that can interact with various receptors and ion channels in the body, leading to the observed effects. In the medical field, mollusk venoms are studied for their potential therapeutic applications, such as in the development of new drugs for pain management, cancer treatment, and other conditions. However, they are also a significant source of poisoning for humans and animals, particularly in areas where mollusks are commonly consumed as food.

Benzilates are esters of benzoic acid and alcohols. They are commonly used as preservatives in pharmaceuticals and personal care products, as well as in food and beverages. In the medical field, benzilates are used as antiseptics and disinfectants to prevent the growth of microorganisms on surfaces and in solutions. They are also used as intermediates in the synthesis of other chemicals. Some benzilates have been reported to have potential toxic effects, including skin irritation and sensitization, and may cause allergic reactions in some individuals.

Sodium is an essential mineral that plays a crucial role in various bodily functions. In the medical field, sodium is often measured in the blood and urine to assess its levels and monitor its balance in the body. Sodium is primarily responsible for regulating the body's fluid balance, which is essential for maintaining blood pressure and proper functioning of the heart, kidneys, and other organs. Sodium is also involved in nerve impulse transmission, muscle contraction, and the production of stomach acid. Abnormal levels of sodium in the body can lead to various medical conditions, including hyponatremia (low sodium levels), hypernatremia (high sodium levels), and dehydration. Sodium levels can be affected by various factors, including diet, medications, and underlying medical conditions. In the medical field, sodium levels are typically measured using a blood test called a serum sodium test or a urine test called a urine sodium test. These tests can help diagnose and monitor various medical conditions related to sodium levels, such as kidney disease, heart failure, and electrolyte imbalances.

The corpus striatum is a part of the brain that plays a crucial role in movement control, reward processing, and cognitive functions. It is located in the basal ganglia, a group of subcortical nuclei in the brain that are involved in a wide range of functions, including motor control, learning, and memory. The corpus striatum is composed of two main structures: the caudate nucleus and the putamen. These structures are interconnected and work together to process information and coordinate movement. The corpus striatum receives input from various parts of the brain, including the cerebral cortex, thalamus, and cerebellum, and sends output to other parts of the brain, including the globus pallidus and substantia nigra. Damage to the corpus striatum can result in a range of movement disorders, such as Parkinson's disease, Huntington's disease, and dystonia. It can also affect cognitive functions, such as learning and memory, and can lead to behavioral and emotional changes.

In the medical field, nitro compounds refer to a class of organic compounds that contain the nitro group (-NO2) as a functional group. These compounds are known for their ability to release nitric oxide (NO) when they are metabolized or decomposed. Nitric oxide is a gas that plays a crucial role in various physiological processes in the body, including vasodilation (widening of blood vessels), neurotransmission, and immune function. Nitro compounds can be used as medications to enhance the production of nitric oxide and improve blood flow to the heart and brain, which can be beneficial in the treatment of conditions such as angina, heart attack, and stroke. However, some nitro compounds can also be toxic and can cause adverse effects when ingested or inhaled. For example, some explosives and military-grade munitions contain nitro compounds, and exposure to these compounds can cause respiratory distress, burns, and other injuries. Therefore, proper handling and storage of nitro compounds are essential to prevent accidental exposure and ensure their safe use in medical applications.

Phentolamine is a medication that is used to treat a variety of conditions, including high blood pressure, Raynaud's disease, and erectile dysfunction. It is a non-selective alpha-adrenergic antagonist, which means that it blocks the action of certain hormones and neurotransmitters that cause blood vessels to constrict. This can help to relax blood vessels and improve blood flow to the affected area. Phentolamine is available in both oral and injectable forms, and it is usually given as a short-acting medication. It is important to note that phentolamine can cause side effects, including dizziness, headache, and rapid heartbeat, and it should only be used under the supervision of a healthcare professional.

Scopolamine derivatives are a class of drugs that are derived from the plant Datura stramonium, also known as the Jimson weed. These drugs are known for their potent anticholinergic effects, which means that they block the action of acetylcholine, a neurotransmitter that plays a key role in many bodily functions. Scopolamine derivatives are often used in the medical field to treat certain conditions, such as motion sickness, nausea, and vomiting. They are also sometimes used to treat certain types of tremors and to reduce muscle spasms. However, these drugs can also have serious side effects, including confusion, dizziness, and hallucinations, and they can be addictive if used for a long period of time. Scopolamine derivatives are available in a variety of forms, including tablets, patches, and injections. They are typically prescribed by a healthcare provider and should only be used under the supervision of a qualified medical professional.

Tacrine is a medication that is used to treat mild to moderate symptoms of Alzheimer's disease. It works by inhibiting the breakdown of acetylcholine, a neurotransmitter that is important for memory and learning. Tacrine is available in tablet form and is usually taken three times a day. It can cause side effects such as nausea, vomiting, diarrhea, and stomach pain. It is important to take tacrine exactly as prescribed by a doctor, as taking too much can be dangerous.

Denervation refers to the loss of nerve supply to a particular tissue or organ. This can occur due to various reasons such as injury, disease, or surgical removal of the nerve. When a tissue or organ is denervated, it loses its ability to receive signals from the nervous system, which can lead to a range of symptoms and complications. In the medical field, denervation can have significant implications for the diagnosis and treatment of various conditions. For example, denervation of the muscles can lead to muscle weakness or paralysis, while denervation of the heart can lead to arrhythmias or other cardiac problems. In some cases, denervation may be reversible with appropriate treatment, while in other cases it may be permanent.

Snake venoms are complex mixtures of proteins and other molecules that are produced by venom glands in snakes. These venoms are used by snakes as a means of defense against predators or as a tool for capturing prey. The effects of snake venom can vary widely depending on the species of snake and the specific components of the venom. Some snake venoms are primarily hemotoxic, meaning they cause damage to blood vessels and can lead to internal bleeding or organ failure. Other snake venoms are neurotoxic, meaning they affect the nervous system and can cause paralysis or respiratory failure. Still, other snake venoms are myotoxic, meaning they cause damage to muscle tissue. In the medical field, snake venoms are studied for their potential therapeutic uses. Some components of snake venom have been found to have anti-inflammatory, anti-cancer, or anti-viral properties. Additionally, some snake venom components have been used to develop new drugs for the treatment of conditions such as heart disease, stroke, and diabetes. However, it is important to note that snake venom can also be dangerous and can cause serious harm or death if not treated properly.

Neuromuscular junction (NMJ) diseases are a group of disorders that affect the communication between nerves and muscles. The NMJ is the point where the nerve endings (axons) of motor neurons connect to muscle fibers. This connection allows the nerve to transmit signals to the muscle, causing it to contract. NMJ diseases can be caused by a variety of factors, including genetic mutations, autoimmune disorders, and exposure to certain toxins. Some common examples of NMJ diseases include myasthenia gravis, Lambert-Eaton myasthenic syndrome, and congenital myasthenic syndromes. Symptoms of NMJ diseases can vary depending on the specific disorder, but may include muscle weakness, fatigue, difficulty swallowing, and drooping eyelids. Treatment for NMJ diseases typically involves medications to improve muscle function, physical therapy, and in some cases, surgery.

Nitric oxide synthase type III (NOS3) is an enzyme that is primarily found in the endothelial cells of blood vessels. It is responsible for the production of nitric oxide (NO), a gas that plays a crucial role in regulating blood flow and blood pressure. NOS3 is activated by various stimuli, including shear stress, which is caused by the flow of blood through the blood vessels. When activated, NOS3 produces NO, which causes the smooth muscle cells in the blood vessels to relax, allowing blood to flow more easily. This helps to regulate blood pressure and maintain proper blood flow to the body's tissues. In addition to its role in regulating blood flow, NOS3 has been implicated in a number of other physiological processes, including the immune response, neurotransmission, and the development of certain diseases, such as atherosclerosis and hypertension. Disruptions in NOS3 function have been linked to a number of cardiovascular diseases, including heart attack, stroke, and peripheral artery disease. As a result, NOS3 is an important target for the development of new treatments for these conditions.

Autoradiography is a technique used in the medical field to visualize the distribution of radioactive substances within a biological sample. It involves exposing a sample to a small amount of a radioactive tracer, which emits radiation as it decays. The emitted radiation is then detected and recorded using a special film or imaging device, which produces an image of the distribution of the tracer within the sample. Autoradiography is commonly used in medical research to study the metabolism and distribution of drugs, hormones, and other substances within the body. It can also be used to study the growth and spread of tumors, as well as to investigate the structure and function of cells and tissues. In some cases, autoradiography can be used to visualize the distribution of specific proteins or other molecules within cells and tissues.

Charybdotoxin is a type of scorpion venom that is known to block voltage-gated potassium channels. It is a potent neurotoxin that can cause muscle paralysis, respiratory failure, and even death in humans. In the medical field, charybdotoxin is used as a research tool to study the function of potassium channels and to develop new treatments for conditions such as hypertension and epilepsy. It is also used in the development of new pain medications.

Azirines are a class of organic compounds that contain a three-membered nitrogen ring. They are often used as intermediates in the synthesis of other organic compounds, and have potential applications in the medical field as well. One example of a medical application of azirines is in the development of antiviral drugs. Azirines have been shown to have antiviral activity against a variety of viruses, including HIV and influenza. They work by inhibiting the replication of the viral genome, which can help to prevent the spread of the virus within the body. Azirines have also been studied for their potential use in the treatment of cancer. Some azirines have been shown to have cytotoxic activity against cancer cells, which means that they can kill cancer cells or inhibit their growth. This makes them a promising class of compounds for the development of new cancer treatments. Overall, azirines have a number of potential applications in the medical field, and ongoing research is exploring their use in the development of new drugs and therapies.

Calcimycin, also known as FK506, is a medication that belongs to a class of drugs called immunosuppressants. It is primarily used to prevent organ rejection in people who have received a transplant, such as a kidney or liver transplant. Calcimycin works by inhibiting the activity of a protein called calcineurin, which plays a key role in the activation of T-cells, a type of white blood cell that is involved in the immune response. By inhibiting calcineurin, calcimycin helps to suppress the immune system and reduce the risk of organ rejection. Calcimycin is usually given as an oral tablet or as an injection. It can cause side effects such as headache, nausea, and diarrhea, and it may interact with other medications.

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Papaverine is a medication that is used to treat a variety of medical conditions, including erectile dysfunction, Raynaud's disease, and glaucoma. It is a vasodilator, which means that it helps to widen blood vessels and improve blood flow. Papaverine is usually administered intravenously or intramuscularly, and it can cause side effects such as headache, nausea, and dizziness. It is important to note that papaverine should only be used under the supervision of a healthcare professional.

Tremorine is a medication that is used to treat Parkinson's disease and other movement disorders. It is a type of medication called a dopamine agonist, which works by increasing the levels of dopamine in the brain. Dopamine is a chemical that is involved in controlling movement, and a lack of dopamine can cause symptoms such as tremors, stiffness, and difficulty with balance and coordination. Tremorine is available in tablet and injectable forms and is typically taken once or twice a day. It can cause side effects such as nausea, dizziness, and hallucinations, and may interact with other medications.

In the medical field, "Animals, Newborn" typically refers to animals that are less than 28 days old. This age range is often used to describe the developmental stage of animals, particularly in the context of research or veterinary medicine. Newborn animals may require specialized care and attention, as they are often more vulnerable to illness and injury than older animals. They may also have unique nutritional and behavioral needs that must be addressed in order to promote their growth and development. In some cases, newborn animals may be used in medical research to study various biological processes, such as development, growth, and disease. However, the use of animals in research is highly regulated, and strict ethical guidelines must be followed to ensure the welfare and safety of the animals involved.

Cyclic GMP (cGMP) is a signaling molecule that plays a crucial role in regulating various physiological processes in the body, including smooth muscle contraction, neurotransmission, and blood pressure regulation. It is synthesized from guanosine triphosphate (GTP) by the enzyme guanylate cyclase and is degraded by the enzyme phosphodiesterase. In the medical field, cGMP is often studied in the context of its role in the regulation of blood vessels and the cardiovascular system. For example, cGMP is involved in the dilation of blood vessels, which helps to lower blood pressure and improve blood flow. It is also involved in the regulation of heart rate and contractility. Abnormal levels of cGMP can lead to a variety of medical conditions, including hypertension, heart failure, and erectile dysfunction. In these cases, medications that either increase or decrease cGMP levels may be used to treat the underlying condition.

Adenosine is a naturally occurring nucleoside that plays a crucial role in various physiological processes in the human body. It is a component of the nucleic acids DNA and RNA and is also found in high concentrations in the cells of the heart, brain, and other organs. In the medical field, adenosine is often used as a medication to treat certain heart conditions, such as supraventricular tachycardia (SVT) and atrial fibrillation (AFib). Adenosine works by blocking the electrical signals that cause the heart to beat too fast or irregularly. It is typically administered as an intravenous injection and has a short duration of action, lasting only a few minutes. Adenosine is also used in research to study the function of various cells and tissues in the body, including the nervous system, immune system, and cardiovascular system. It has been shown to have a wide range of effects on cellular signaling pathways, including the regulation of gene expression, cell proliferation, and apoptosis (cell death).

Bethanechol is a medication that is used to treat urinary retention, a condition in which a person is unable to empty their bladder completely. It works by stimulating the muscles in the bladder and urinary tract to contract, which helps to empty the bladder. Bethanechol is usually given as an injection or a suppository, and it is typically used in people who are unable to urinate due to surgery, injury, or certain medical conditions. It is important to note that bethanechol can cause side effects, such as nausea, vomiting, and diarrhea, and it should only be used under the supervision of a healthcare provider.

Autonomic fibers, postganglionic, refer to the nerves that carry signals from the ganglia (nerve cell clusters) to the target organs in the autonomic nervous system. The autonomic nervous system is responsible for regulating involuntary bodily functions such as heart rate, digestion, and blood pressure. Postganglionic autonomic fibers are classified into two types: sympathetic and parasympathetic. The sympathetic nervous system is responsible for the "fight or flight" response, increasing heart rate, blood pressure, and respiration, and decreasing digestion and other non-essential functions. The parasympathetic nervous system, on the other hand, is responsible for the "rest and digest" response, slowing heart rate, decreasing blood pressure, and increasing digestion and other non-essential functions. Postganglionic autonomic fibers are typically classified based on the neurotransmitters they use to communicate with their target organs. For example, sympathetic postganglionic fibers typically use norepinephrine as their neurotransmitter, while parasympathetic postganglionic fibers typically use acetylcholine.

Amobarbital is a barbiturate medication that is used to treat a variety of conditions, including anxiety, insomnia, and seizures. It is a central nervous system depressant that works by slowing down activity in the brain and nervous system. Amobarbital is available in both oral and injectable forms and is typically prescribed for short-term use only. It can cause drowsiness, dizziness, and other side effects, and may be habit-forming if used for an extended period of time. Amobarbital is a controlled substance and is regulated by the U.S. Food and Drug Administration (FDA).

Calcium channel blockers are a class of medications that work by blocking the movement of calcium ions into cardiac and smooth muscle cells, as well as into some types of neurons. This leads to a decrease in the contraction of the heart muscle, which can help to lower blood pressure and slow the heart rate. Calcium channel blockers are commonly used to treat high blood pressure, angina (chest pain), and certain types of heart rhythm disorders. They are also sometimes used to treat migraines and other types of headache. There are several different types of calcium channel blockers, including dihydropyridines, verapamil, and diltiazem.

Epinephrine, also known as adrenaline, is a hormone and neurotransmitter that plays a crucial role in the body's "fight or flight" response. It is produced by the adrenal glands and is released into the bloodstream in response to stress or danger. In the medical field, epinephrine is used as a medication to treat a variety of conditions, including anaphylaxis (a severe allergic reaction), cardiac arrest, and asthma. It works by constricting blood vessels, increasing heart rate and contractility, and relaxing smooth muscles in the bronchial tubes, which can help to open airways and improve breathing. Epinephrine is typically administered via injection, either intravenously or subcutaneously (under the skin). It is a powerful medication and should only be used under the guidance of a healthcare professional.

Bethanechol compounds are a class of drugs that are used to stimulate the contractions of smooth muscles in the body. They are primarily used to treat conditions such as urinary retention, constipation, and gastrointestinal disorders. Bethanechol works by activating muscarinic receptors in the smooth muscles, which leads to increased muscle contractions. It is available in both oral and injectable forms.

In the medical field, RNA, Messenger (mRNA) refers to a type of RNA molecule that carries genetic information from DNA in the nucleus of a cell to the ribosomes, where proteins are synthesized. During the process of transcription, the DNA sequence of a gene is copied into a complementary RNA sequence called messenger RNA (mRNA). This mRNA molecule then leaves the nucleus and travels to the cytoplasm of the cell, where it binds to ribosomes and serves as a template for the synthesis of a specific protein. The sequence of nucleotides in the mRNA molecule determines the sequence of amino acids in the protein that is synthesized. Therefore, changes in the sequence of nucleotides in the mRNA molecule can result in changes in the amino acid sequence of the protein, which can affect the function of the protein and potentially lead to disease. mRNA molecules are often used in medical research and therapy as a way to introduce new genetic information into cells. For example, mRNA vaccines work by introducing a small piece of mRNA that encodes for a specific protein, which triggers an immune response in the body.

Barium is a chemical element with the symbol Ba and atomic number 56. In the medical field, barium is commonly used as a contrast agent in imaging studies, particularly in the gastrointestinal (GI) tract. Barium sulfate is the most commonly used form of barium in medical imaging. It is administered orally or through an enema, and it coats the lining of the GI tract, making it easier to see on X-rays. Barium studies are used to diagnose a variety of conditions in the digestive system, including ulcers, tumors, inflammation, and structural abnormalities. Barium is also used in other medical applications, such as in the treatment of certain types of arrhythmias (irregular heartbeats) and in the production of certain types of glass and ceramics. However, in these applications, barium is typically used in much smaller quantities and under more controlled conditions.

Edrophonium, also known as Tensilon, is a medication used in the medical field to diagnose myasthenia gravis, a disorder that causes muscle weakness. It works by blocking the action of acetylcholinesterase, an enzyme that breaks down acetylcholine, a neurotransmitter that triggers muscle contraction. When acetylcholine levels are increased, muscle weakness improves, allowing doctors to diagnose myasthenia gravis. Edrophonium is usually administered as an intravenous injection and its effects can be observed within minutes. It is also used to reverse the effects of certain types of muscle relaxants, such as succinylcholine, during surgery.

The adrenal medulla is the inner part of the adrenal gland, located adjacent to the outer adrenal cortex. It is responsible for producing and secreting hormones that regulate the body's response to stress, including adrenaline (epinephrine) and noradrenaline (norepinephrine). These hormones are released into the bloodstream in response to stressors such as physical exertion, fear, or injury, and help to increase heart rate, blood pressure, and blood sugar levels, preparing the body for a fight or flight response. The adrenal medulla is innervated by the sympathetic nervous system, which controls the body's response to stress.

Botulinum toxins are a group of neurotoxins produced by the bacterium Clostridium botulinum. These toxins are used in the medical field for a variety of therapeutic purposes, including the treatment of muscle spasms, wrinkles, and other conditions. Botulinum toxins work by blocking the release of a neurotransmitter called acetylcholine, which is responsible for transmitting signals between nerve cells. When acetylcholine is blocked, the muscles that it controls become relaxed, which can help to reduce muscle spasms and wrinkles. There are several different types of botulinum toxins, each with slightly different properties and uses. The most commonly used types are Botox, Dysport, and Xeomin. These toxins are typically injected into the affected muscles to achieve the desired therapeutic effect. Botulinum toxins are generally considered safe and effective when used by trained medical professionals. However, like all medications, they can cause side effects, such as pain, redness, and swelling at the injection site, and in rare cases, more serious complications. It is important to discuss the potential risks and benefits of botulinum toxin therapy with a healthcare provider before undergoing treatment.

Butyrylcholinesterase (BuChE) is an enzyme that plays a crucial role in the breakdown of acetylcholine, a neurotransmitter that is involved in many important bodily functions. BuChE is primarily found in the blood and in the liver, but it is also present in other tissues throughout the body. In the medical field, BuChE is often measured as a way to assess liver function, as the enzyme is produced by liver cells. Abnormal levels of BuChE can be an indication of liver disease or other conditions that affect liver function. BuChE is also used as a biomarker for exposure to certain toxins, such as pesticides and heavy metals. In addition, researchers are studying BuChE as a potential target for the development of new drugs for the treatment of neurological disorders, such as Alzheimer's disease.

Glutamic acid is an amino acid that is naturally occurring in the human body and is essential for various bodily functions. It is a non-essential amino acid, meaning that the body can produce it from other compounds, but it is still important for maintaining good health. In the medical field, glutamic acid is sometimes used as a medication to treat certain conditions. For example, it is used to treat epilepsy, a neurological disorder characterized by recurrent seizures. Glutamic acid is also used to treat certain types of brain injuries, such as stroke, by promoting the growth of new brain cells. In addition to its medicinal uses, glutamic acid is also an important component of the diet. It is found in many foods, including meats, fish, poultry, dairy products, and grains. It is also available as a dietary supplement.

Benzazepines are a class of psychoactive drugs that are structurally related to benzodiazepines. They are characterized by the presence of a benzene ring fused to an azepine ring, which gives them their unique chemical structure and pharmacological properties. Benzazepines are primarily used as anxiolytics, sedatives, and hypnotics to treat conditions such as anxiety, insomnia, and agitation. They work by enhancing the activity of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain, which helps to reduce anxiety and promote relaxation. Some examples of benzazepines include thienotriazolodiazepines (e.g., flunitrazepam), dibenzazepines (e.g., zolpidem), and benzodiazepine-like compounds (e.g., alprazolam). However, benzazepines are generally less commonly used than benzodiazepines due to their potential for abuse and dependence, as well as their side effects, which can include drowsiness, dizziness, and impaired coordination.

In the medical field, Bicyclo Compounds are a class of organic compounds that contain two rings connected by a single carbon-carbon bond. These compounds are often used as pharmaceuticals and have a wide range of biological activities, including analgesic, anti-inflammatory, and anti-cancer properties. Some examples of bicyclo compounds include the anti-inflammatory drug ibuprofen and the anti-cancer drug taxol.

Muscle proteins are proteins that are found in muscle tissue. They are responsible for the structure, function, and repair of muscle fibers. There are two main types of muscle proteins: contractile proteins and regulatory proteins. Contractile proteins are responsible for the contraction of muscle fibers. The most important contractile protein is actin, which is found in the cytoplasm of muscle fibers. Actin interacts with another protein called myosin, which is found in the sarcomeres (the functional units of muscle fibers). When myosin binds to actin, it causes the muscle fiber to contract. Regulatory proteins are responsible for controlling the contraction of muscle fibers. They include troponin and tropomyosin, which regulate the interaction between actin and myosin. Calcium ions also play a role in regulating muscle contraction by binding to troponin and causing it to change shape, allowing myosin to bind to actin. Muscle proteins are important for maintaining muscle strength and function. They are also involved in muscle growth and repair, and can be affected by various medical conditions and diseases, such as muscular dystrophy, sarcopenia, and cancer.

In the medical field, Tropanes are a class of organic compounds that are derived from the alkaloid tropine. They are known for their ability to interact with the cholinergic system in the brain, which can lead to a range of effects on the central nervous system. Some of the most well-known tropane compounds include atropine, scopolamine, and hyoscyamine. These compounds are often used as medications to treat a variety of conditions, including motion sickness, glaucoma, and overactive bladder. They can also be used as muscle relaxants and as sedatives. However, tropane compounds can also have side effects, including dry mouth, blurred vision, dizziness, and confusion. In some cases, they can also be toxic in high doses, and they may interact with other medications or medical conditions. As a result, tropane compounds are typically used with caution and under the supervision of a healthcare professional.

Bronchi are the large tubes that carry air from the trachea (windpipe) to the lungs. There are two main bronchi, one for each lung, that branch off from the trachea and continue to divide into smaller and smaller tubes called bronchioles. The bronchi are lined with cilia and mucus-secreting cells that help to trap and remove dust, bacteria, and other particles from the air we breathe. In the medical field, bronchi are often studied in the context of respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer.

Brain chemistry refers to the chemical processes that occur within the brain, including the production, release, and regulation of neurotransmitters, hormones, and other chemical messengers. These chemical processes play a critical role in regulating mood, behavior, cognition, and other aspects of brain function. In the medical field, brain chemistry is often studied in the context of neurological and psychiatric disorders, such as depression, anxiety, schizophrenia, and addiction. By understanding the underlying chemical imbalances or abnormalities in the brain, researchers and healthcare providers can develop more effective treatments for these conditions. Some common neurotransmitters and hormones involved in brain chemistry include dopamine, serotonin, norepinephrine, acetylcholine, and cortisol. Medications such as antidepressants, antipsychotics, and mood stabilizers often work by altering the levels of these chemicals in the brain to improve symptoms of various disorders.

Cyclic AMP (cAMP) is a signaling molecule that plays a crucial role in many cellular processes, including metabolism, gene expression, and cell proliferation. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase, and its levels are regulated by various hormones and neurotransmitters. In the medical field, cAMP is often studied in the context of its role in regulating cellular signaling pathways. For example, cAMP is involved in the regulation of the immune system, where it helps to activate immune cells and promote inflammation. It is also involved in the regulation of the cardiovascular system, where it helps to regulate heart rate and blood pressure. In addition, cAMP is often used as a tool in research to study cellular signaling pathways. For example, it is commonly used to activate or inhibit specific signaling pathways in cells, allowing researchers to study the effects of these pathways on cellular function.

CHO cells are a type of Chinese hamster ovary (CHO) cell line that is commonly used in the biotechnology industry for the production of recombinant proteins. These cells are derived from the ovaries of Chinese hamsters and have been genetically modified to produce large amounts of a specific protein or protein complex. CHO cells are often used as a host cell for the production of therapeutic proteins, such as monoclonal antibodies, growth factors, and enzymes. They are also used in research to study the structure and function of proteins, as well as to test the safety and efficacy of new drugs. One of the advantages of using CHO cells is that they are relatively easy to culture and can be grown in large quantities. They are also able to produce high levels of recombinant proteins, making them a popular choice for the production of biopharmaceuticals. However, like all cell lines, CHO cells can also have limitations and may not be suitable for all types of protein production.

Analysis of Variance (ANOVA) is a statistical method used to compare the means of three or more groups. In the medical field, ANOVA can be used to compare the effectiveness of different treatments, interventions, or medications on a particular outcome or variable of interest. For example, a researcher may want to compare the effectiveness of three different medications for treating a particular disease. They could use ANOVA to compare the mean response (e.g., improvement in symptoms) between the three groups of patients who received each medication. If the results show a significant difference between the groups, it would suggest that one medication is more effective than the others. ANOVA can also be used to compare the means of different groups of patients based on a categorical variable, such as age, gender, or race. For example, a researcher may want to compare the mean blood pressure of patients in different age groups. They could use ANOVA to compare the mean blood pressure between the different age groups and determine if there are significant differences. Overall, ANOVA is a powerful statistical tool that can be used to compare the means of different groups in the medical field, helping researchers to identify which treatments or interventions are most effective and to better understand the factors that influence health outcomes.

Receptors, presynaptic are specialized proteins located on the surface of nerve terminals, which are the endings of neurons that release neurotransmitters. These receptors are responsible for detecting and responding to signals from other neurons or from the environment, and they play a crucial role in the transmission of signals within the nervous system. When a neurotransmitter binds to a presynaptic receptor, it can trigger a series of events that lead to the release of additional neurotransmitters or the inhibition of neurotransmitter release. This process is essential for the proper functioning of the nervous system and for the regulation of a wide range of physiological processes, including mood, cognition, and movement. Presynaptic receptors can be classified into several different types, including ionotropic receptors, which are directly linked to ion channels and can cause rapid changes in the membrane potential of the neuron, and metabotropic receptors, which are linked to intracellular signaling pathways and can cause slower, more prolonged changes in the neuron's activity.

Reserpine is a natural alkaloid that was originally isolated from the plant Rauvolfia serpentina, also known as the Indian snakeroot. It is a potent antagonist of the sympathetic nervous system, which means it blocks the effects of norepinephrine, a neurotransmitter that plays a key role in the body's "fight or flight" response. In the medical field, reserpine is primarily used as a medication to treat high blood pressure. It works by reducing the production of norepinephrine in the body, which can help lower blood pressure and reduce the risk of heart attack and stroke. Reserpine is also sometimes used to treat anxiety, depression, and other conditions that are thought to be related to imbalances in the sympathetic nervous system. Reserpine can cause a number of side effects, including dizziness, weakness, fatigue, and dry mouth. It can also cause more serious side effects, such as low blood pressure, rapid heart rate, and depression. As with any medication, it is important to talk to your doctor about the potential risks and benefits of taking reserpine, and to follow their instructions carefully.

Oxadiazoles are a class of heterocyclic compounds that contain a six-membered ring with two nitrogen atoms and one oxygen atom. They are commonly used in the medical field as pharmaceuticals due to their diverse range of biological activities, including anticonvulsant, antihypertensive, and antipsychotic properties. One of the most well-known examples of an oxadiazole in medicine is diazepam, which is a benzodiazepine used to treat anxiety, seizures, and muscle spasms. Other oxadiazoles that have been used in medicine include clonazepam, lorazepam, and oxazepam. In addition to their use as pharmaceuticals, oxadiazoles have also been studied for their potential use in the treatment of various diseases, including cancer, viral infections, and neurological disorders. However, more research is needed to fully understand their therapeutic potential and potential side effects.

Pyridostigmine Bromide is a medication used to treat myasthenia gravis, a disorder that causes muscle weakness and fatigue. It works by increasing the amount of a chemical called acetylcholine in the body, which helps to improve muscle strength and control. Pyridostigmine Bromide is usually taken by mouth, and the dosage may be adjusted based on the severity of the patient's symptoms. It may cause side effects such as nausea, diarrhea, and muscle cramps. Pyridostigmine Bromide is also used to treat certain types of nerve damage, such as that caused by nerve agents or certain types of chemotherapy.

Diazonium compounds are organic compounds that contain a diazonium ion (-N2+) as a functional group. They are typically prepared by the reaction of a primary amine with a strong acid, such as sulfuric acid, to form a diazonium salt. Diazonium compounds have a variety of applications in the medical field, including as intermediates in the synthesis of dyes, drugs, and other organic compounds. They can also be used as diagnostic agents in radiology, as well as in the treatment of certain medical conditions, such as hypertension and angina pectoris. However, diazonium compounds can also be toxic and can cause skin irritation, respiratory problems, and other adverse effects if not handled properly.

Chlorides are a type of anion that are commonly found in the human body. They are produced when chlorine combines with other elements, such as sodium or potassium, to form compounds. In the body, chlorides are primarily found in the fluid that surrounds cells, known as extracellular fluid, and in the fluid that fills the lungs and other cavities, known as intracellular fluid. Chlorides play an important role in maintaining the balance of fluids in the body and in regulating the pH of the blood. They also help to transport nutrients and waste products throughout the body. Chlorides are an essential component of many bodily functions, including the production of hydrochloric acid in the stomach, which aids in the digestion of food. In the medical field, chlorides are often measured as part of a routine blood test to assess the overall health of the body. Abnormal levels of chlorides in the blood can be a sign of a variety of medical conditions, including kidney disease, liver disease, and respiratory disorders.

Aminopyridines are a class of drugs that are used to treat certain types of muscle spasms and tremors. They work by blocking the action of a neurotransmitter called acetylcholine, which helps to relax muscles. Aminopyridines are often used to treat conditions such as Parkinson's disease, multiple sclerosis, and spinal cord injuries. They are usually taken orally, but can also be given intravenously or intramuscularly. Common examples of aminopyridines include pyridostigmine, neostigmine, and physostigmine.

In the medical field, "Disease Models, Animal" refers to the use of animals to study and understand human diseases. These models are created by introducing a disease or condition into an animal, either naturally or through experimental manipulation, in order to study its progression, symptoms, and potential treatments. Animal models are used in medical research because they allow scientists to study diseases in a controlled environment and to test potential treatments before they are tested in humans. They can also provide insights into the underlying mechanisms of a disease and help to identify new therapeutic targets. There are many different types of animal models used in medical research, including mice, rats, rabbits, dogs, and monkeys. Each type of animal has its own advantages and disadvantages, and the choice of model depends on the specific disease being studied and the research question being addressed.

Cricetinae is a subfamily of rodents that includes hamsters, voles, and lemmings. These animals are typically small to medium-sized and have a broad, flat head and a short, thick body. They are found in a variety of habitats around the world, including grasslands, forests, and deserts. In the medical field, Cricetinae are often used as laboratory animals for research purposes, as they are easy to care for and breed, and have a relatively short lifespan. They are also used in studies of genetics, physiology, and behavior.

Tobacco Use Disorder (TUD) is a medical condition characterized by the excessive and compulsive use of tobacco products, despite the harmful effects on an individual's health. TUD is classified into two main types: nicotine dependence and tobacco addiction. Nicotine dependence refers to the physical and psychological dependence on nicotine, which is the primary addictive substance in tobacco products. Symptoms of nicotine dependence include cravings, withdrawal symptoms such as irritability, anxiety, and difficulty concentrating, and an inability to quit smoking despite the desire to do so. Tobacco addiction, on the other hand, is a more complex disorder that involves both physical and psychological dependence on tobacco products. It is characterized by a strong desire to use tobacco, a lack of control over tobacco use, and continued use despite the negative consequences. TUD is a serious medical condition that can lead to a range of health problems, including cancer, heart disease, respiratory diseases, and stroke. Treatment for TUD typically involves a combination of behavioral therapy, medication, and support groups to help individuals quit smoking and manage withdrawal symptoms.

Morphine is a powerful opioid medication that is used to relieve severe pain. It is derived from the opium poppy and is one of the most potent naturally occurring opioids. Morphine works by binding to specific receptors in the brain and spinal cord, which can reduce the perception of pain and produce feelings of euphoria. It is often prescribed for patients who are experiencing severe pain, such as those with cancer or after surgery. Morphine can be administered in a variety of ways, including orally, intravenously, or through injection. It can also be used in combination with other medications to enhance its pain-relieving effects. However, morphine can also be highly addictive and can lead to dependence and withdrawal symptoms if used for an extended period of time. It is important for patients to use morphine only as directed by their healthcare provider and to avoid taking more than the recommended dose.

In the medical field, a peptide fragment refers to a short chain of amino acids that are derived from a larger peptide or protein molecule. Peptide fragments can be generated through various techniques, such as enzymatic digestion or chemical cleavage, and are often used in diagnostic and therapeutic applications. Peptide fragments can be used as biomarkers for various diseases, as they may be present in the body at elevated levels in response to specific conditions. For example, certain peptide fragments have been identified as potential biomarkers for cancer, neurodegenerative diseases, and cardiovascular disease. In addition, peptide fragments can be used as therapeutic agents themselves. For example, some peptide fragments have been shown to have anti-inflammatory or anti-cancer properties, and are being investigated as potential treatments for various diseases. Overall, peptide fragments play an important role in the medical field, both as diagnostic tools and as potential therapeutic agents.

GTP-binding proteins, also known as G proteins, are a family of proteins that play a crucial role in signal transduction in cells. They are involved in a wide range of cellular processes, including cell growth, differentiation, and metabolism. G proteins are composed of three subunits: an alpha subunit, a beta subunit, and a gamma subunit. The alpha subunit is the one that binds to guanosine triphosphate (GTP), a molecule that is involved in regulating the activity of the protein. When GTP binds to the alpha subunit, it causes a conformational change in the protein, which in turn activates or inhibits downstream signaling pathways. G proteins are activated by a variety of extracellular signals, such as hormones, neurotransmitters, and growth factors. Once activated, they can interact with other proteins in the cell, such as enzymes or ion channels, to transmit the signal and initiate a cellular response. G proteins are found in all eukaryotic cells and play a critical role in many physiological processes. They are also involved in a number of diseases, including cancer, neurological disorders, and cardiovascular diseases.

Lobeline is a naturally occurring alkaloid found in the plant Lobelia inflata, also known as Indian tobacco or pukeweed. It has been used in traditional medicine for its bronchodilatory and anti-inflammatory effects, and has been studied for its potential therapeutic uses in the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). In the medical field, lobeline is sometimes used as a bronchodilator, which helps to relax and widen the airways in the lungs, making it easier to breathe. It is also sometimes used as an anti-inflammatory agent to reduce inflammation in the airways and lungs. However, it is important to note that lobeline is not currently approved for use as a medical treatment by regulatory agencies such as the US Food and Drug Administration (FDA). Its use in medicine is limited and primarily involves research studies and clinical trials.

Receptors, Neurotransmitter are proteins found on the surface of neurons that bind to specific neurotransmitters, such as dopamine, serotonin, or glutamate. These receptors are responsible for transmitting signals across the synapse, the gap between neurons, and play a crucial role in regulating various physiological processes, including mood, memory, and movement. Dysfunction of neurotransmitter receptors has been implicated in a variety of neurological and psychiatric disorders, including depression, anxiety, and schizophrenia.

In the medical field, "Behavior, Animal" refers to the study of the actions, responses, and interactions of animals, including humans, with their environment. This field encompasses a wide range of topics, including animal behavior in the wild, animal behavior in captivity, animal behavior in domestic settings, and animal behavior in laboratory settings. Animal behaviorists study a variety of behaviors, including social behavior, mating behavior, feeding behavior, communication behavior, and aggression. They use a variety of research methods, including observational studies, experiments, and surveys, to understand the underlying mechanisms that drive animal behavior. Animal behavior research has important applications in fields such as conservation biology, animal welfare, and veterinary medicine. For example, understanding animal behavior can help conservationists develop effective strategies for protecting endangered species, and it can help veterinarians develop more effective treatments for behavioral disorders in animals.

Potassium channels are a type of ion channel found in the cell membrane of many types of cells, including neurons, muscle cells, and epithelial cells. These channels are responsible for regulating the flow of potassium ions (K+) in and out of the cell, which is important for maintaining the cell's resting membrane potential and controlling the generation and propagation of electrical signals in the cell. Potassium channels are classified into several different types based on their biophysical properties, such as their voltage sensitivity, pharmacology, and gating mechanisms. Some of the most well-known types of potassium channels include voltage-gated potassium channels, inwardly rectifying potassium channels, and leak potassium channels. In the medical field, potassium channels play a critical role in many physiological processes, including muscle contraction, neurotransmission, and regulation of blood pressure. Abnormalities in potassium channel function can lead to a variety of diseases and disorders, such as epilepsy, hypertension, and cardiac arrhythmias. Therefore, understanding the structure and function of potassium channels is important for developing new treatments for these conditions.

Angina pectoris, variant, also known as Prinzmetal's angina or vasospastic angina, is a type of chest pain that occurs due to spasms in the coronary arteries. Unlike stable angina, which is caused by atherosclerosis, variant angina is caused by temporary narrowing or spasm of the coronary arteries, which reduces blood flow to the heart muscle. This can cause chest pain or discomfort, which may be severe and may radiate to the neck, jaw, or arm. Variant angina is less common than stable angina, but it is more likely to occur in women and younger people. It is often treated with medications to relax the coronary arteries and prevent spasms, and in some cases, with procedures such as angioplasty or coronary artery bypass surgery.

Aldicarb is a highly toxic organophosphate insecticide that is used to control a variety of pests, including termites, ants, and cockroaches. It works by inhibiting the enzyme acetylcholinesterase, which is responsible for breaking down the neurotransmitter acetylcholine in the nervous system. When acetylcholinesterase is inhibited, acetylcholine builds up in the nervous system, leading to overstimulation and eventually paralysis and death. In the medical field, aldicarb is not typically used for human treatment, as it is highly toxic and can cause serious health effects, including respiratory distress, convulsions, and death. However, aldicarb poisoning is a potential risk for people who handle or are exposed to the insecticide, and treatment typically involves supportive care, such as oxygen therapy and medications to manage symptoms. In severe cases, hospitalization and intensive care may be necessary.

Strychnine is a highly toxic alkaloid found in certain plants, including the seeds of the Strychnos nux-vomica tree. It is known for its ability to stimulate the central nervous system, leading to symptoms such as muscle spasms, convulsions, and hallucinations. In the medical field, strychnine is sometimes used as a muscle relaxant or as a treatment for certain types of muscle spasms. However, due to its toxicity, it is only used under the supervision of a qualified healthcare professional and is typically administered in very small doses. Strychnine is also used as a pesticide and is sometimes found in illicit drugs.

Chlorisondamine is a medication that is used to treat allergic reactions, including hay fever and allergic rhinitis. It works by blocking the release of histamine, a chemical that is produced by the body in response to an allergen and causes symptoms such as itching, swelling, and runny nose. Chlorisondamine is available as a nasal spray or tablet and is usually taken as needed, usually once or twice a day. It is generally considered safe and well-tolerated, but like all medications, it can cause side effects. Some common side effects of chlorisondamine include dizziness, headache, and nausea.

Nerve tissue proteins are proteins that are found in nerve cells, also known as neurons. These proteins play important roles in the structure and function of neurons, including the transmission of electrical signals along the length of the neuron and the communication between neurons. There are many different types of nerve tissue proteins, each with its own specific function. Some examples of nerve tissue proteins include neurofilaments, which provide structural support for the neuron; microtubules, which help to maintain the shape of the neuron and transport materials within the neuron; and neurofilament light chain, which is involved in the formation of neurofibrillary tangles, which are a hallmark of certain neurodegenerative diseases such as Alzheimer's disease. Nerve tissue proteins are important for the proper functioning of the nervous system and any disruption in their production or function can lead to neurological disorders.

Apamin is a neurotoxin that is found in the venom of the scorpion Apis mellifera, commonly known as the honeybee. It is a small peptide that acts as a selective blocker of voltage-gated potassium channels, particularly the Kv1.1 subtype. In the medical field, apamin has been studied for its potential therapeutic applications. It has been shown to have anti-inflammatory and analgesic effects, and has been used in the treatment of various conditions such as chronic pain, multiple sclerosis, and inflammatory bowel disease. Additionally, apamin has been used as a research tool to study the function of voltage-gated potassium channels in various cell types, including neurons, astrocytes, and smooth muscle cells.

Vasoactive Intestinal Peptide (VIP) is a hormone that is produced by the cells of the gastrointestinal tract, as well as by neurons in the brain and other parts of the body. It is a polypeptide hormone, which means that it is made up of chains of amino acids. VIP has a number of effects on the body, including: 1. Relaxing smooth muscle: VIP can cause the muscles in blood vessels to relax, which can lead to a decrease in blood pressure. 2. Increasing the production of insulin: VIP can stimulate the pancreas to produce more insulin, which is a hormone that helps to regulate blood sugar levels. 3. Regulating the digestive system: VIP can stimulate the production of digestive enzymes and the movement of food through the digestive tract. 4. Modulating the immune system: VIP can help to regulate the immune system and reduce inflammation. VIP is also involved in a number of other physiological processes, including the regulation of heart rate and the contraction of the uterus during childbirth. It is sometimes used as a medication to treat conditions such as irritable bowel syndrome and certain types of diarrhea.

Epilepsy, Frontal Lobe refers to a type of epilepsy that is characterized by seizures that originate in the frontal lobe of the brain. The frontal lobe is responsible for a variety of functions, including decision-making, problem-solving, and social behavior. Frontal lobe epilepsy can present with a variety of symptoms, depending on the specific area of the frontal lobe that is affected. Some common symptoms include changes in behavior or personality, difficulty with speech or language, and changes in mood or emotional state. Seizures may also cause physical symptoms such as loss of consciousness, convulsions, or muscle stiffness. Frontal lobe epilepsy is typically diagnosed through a combination of medical history, physical examination, and imaging studies such as MRI or EEG. Treatment options for frontal lobe epilepsy may include medication, surgery, or other therapies depending on the severity and frequency of seizures, as well as the individual's overall health and medical history.

Cholinesterase reactivators are medications that are used to reverse the effects of cholinesterase inhibitors, which are drugs that block the enzyme cholinesterase. Cholinesterase is an enzyme that breaks down the neurotransmitter acetylcholine, which is important for muscle movement and other bodily functions. When cholinesterase is blocked, acetylcholine builds up in the body, leading to symptoms such as muscle weakness, tremors, and difficulty breathing. Cholinesterase reactivators work by restoring the activity of cholinesterase, allowing the enzyme to break down the excess acetylcholine and alleviate the symptoms of cholinesterase inhibitor poisoning. There are several different types of cholinesterase reactivators, including pralidoxime, obidoxime, and edrophonium. These medications are typically administered intravenously or intramuscularly in the case of severe poisoning. It is important to note that cholinesterase reactivators are not effective against all types of cholinesterase inhibitors, and they may not be able to reverse the effects of certain types of poisoning.

Atrial function refers to the ability of the atria, the upper chambers of the heart, to effectively contract and pump blood into the ventricles, the lower chambers of the heart. This is an important aspect of cardiac function, as proper atrial function is necessary for efficient blood flow and overall heart health. There are several measures of atrial function, including: 1. Atrial electromechanical delay: This refers to the time it takes for electrical signals to travel from the sinoatrial node (the heart's natural pacemaker) to the atria and for the atria to contract. 2. Atrial volume: This refers to the amount of blood that is contained within the atria at any given time. 3. Atrial pressure: This refers to the force exerted by the atria on the ventricles during contraction. 4. Atrial compliance: This refers to the ability of the atria to expand and accommodate an increase in blood volume. Abnormalities in atrial function can be associated with a variety of cardiovascular conditions, including heart failure, atrial fibrillation, and valvular heart disease. Assessment of atrial function is often performed using echocardiography, a non-invasive imaging technique that allows for visualization of the heart's structure and function.

Bretylium compounds are a class of drugs that are used in the medical field to treat certain types of heart arrhythmias, such as atrial fibrillation and ventricular tachycardia. These drugs work by blocking the influx of certain ions, such as sodium and calcium, into cardiac muscle cells, which can help to stabilize the heart rhythm and prevent further arrhythmias from occurring. Bretylium compounds are typically administered intravenously and are used as a last resort when other treatments have failed or are not appropriate. They can cause a number of side effects, including nausea, vomiting, and low blood pressure, and may interact with other medications that are being taken.

Magnesium is a mineral that is essential for many bodily functions. It is involved in over 300 enzymatic reactions in the body, including the production of energy, the synthesis of proteins and DNA, and the regulation of muscle and nerve function. In the medical field, magnesium is used to treat a variety of conditions, including: 1. Hypomagnesemia: A deficiency of magnesium in the blood. This can cause symptoms such as muscle cramps, spasms, and seizures. 2. Cardiac arrhythmias: Abnormal heart rhythms that can be caused by low levels of magnesium. 3. Pre-eclampsia: A condition that can occur during pregnancy and is characterized by high blood pressure and protein in the urine. Magnesium supplementation may be used to treat this condition. 4. Chronic kidney disease: Magnesium is often lost in the urine of people with chronic kidney disease, and supplementation may be necessary to maintain adequate levels. 5. Alcohol withdrawal: Magnesium supplementation may be used to treat symptoms of alcohol withdrawal, such as tremors and seizures. 6. Muscle spasms: Magnesium can help to relax muscles and relieve spasms. 7. Anxiety and depression: Some studies have suggested that magnesium supplementation may help to reduce symptoms of anxiety and depression. Magnesium is available in various forms, including oral tablets, capsules, and intravenous solutions. It is important to note that high levels of magnesium can also be toxic, so it is important to use magnesium supplements under the guidance of a healthcare provider.

Autoantibodies are antibodies that are produced by the immune system against the body's own cells, tissues, or organs. In other words, they are antibodies that mistakenly target and attack the body's own components instead of foreign invaders like viruses or bacteria. Autoantibodies can be present in people with various medical conditions, including autoimmune diseases such as rheumatoid arthritis, lupus, and multiple sclerosis. They can also be found in people with certain infections, cancer, and other diseases. Autoantibodies can cause damage to the body's own cells, tissues, or organs, leading to inflammation, tissue destruction, and other symptoms. They can also interfere with the normal functioning of the body's systems, such as the nervous system, digestive system, and cardiovascular system. Diagnosis of autoantibodies is typically done through blood tests, which can detect the presence of specific autoantibodies in the blood. Treatment for autoimmune diseases that involve autoantibodies may include medications to suppress the immune system, such as corticosteroids or immunosuppressants, as well as other therapies to manage symptoms and prevent complications.

Anesthetics are drugs that are used to produce a state of temporary unconsciousness or insensitivity to pain during medical procedures or surgery. They are typically administered by a healthcare professional, such as a doctor or nurse, and are used to help patients relax, feel more comfortable, and tolerate medical procedures without experiencing pain or discomfort. There are several types of anesthetics, including general anesthetics, which produce a state of complete unconsciousness, and local anesthetics, which numb a specific area of the body. General anesthetics are further divided into inhalational anesthetics, which are breathed in through a mask or tube, and injectable anesthetics, which are administered through a needle. Anesthetics are an essential part of modern medicine and are used in a wide range of medical procedures, including surgeries, dental procedures, and childbirth. However, they can also have side effects, such as nausea, vomiting, dizziness, and difficulty breathing, and can be dangerous if not administered properly. Therefore, it is important for healthcare professionals to be trained in the safe and effective use of anesthetics.

Alcuronium is a non-depolarizing neuromuscular blocking agent that is used in anesthesia to relax the muscles of the respiratory and skeletal systems. It is a quaternary ammonium compound that competes with acetylcholine at the nicotinic receptors on the motor end plate, preventing the release of acetylcholine and thereby blocking muscle contraction. Alcuronium is typically administered intravenously and has a relatively short duration of action, making it useful for short surgical procedures or as an adjunct to other neuromuscular blocking agents. It is also used in intensive care units to assist with mechanical ventilation and to facilitate endotracheal intubation.

Bronchoconstriction is a narrowing of the bronchial tubes, which are the airways that carry air to and from the lungs. This narrowing can be caused by a variety of factors, including inflammation, infection, or exposure to irritants such as smoke or allergens. Bronchoconstriction can make it difficult to breathe and can cause symptoms such as wheezing, coughing, and shortness of breath. It is a common condition that can be treated with medications such as bronchodilators, which help to relax the muscles in the bronchial tubes and improve airflow. In severe cases, hospitalization may be necessary.

Prostaglandins are a group of hormone-like substances that are produced in the body from fatty acids. They play a variety of roles in the body, including regulating inflammation, blood pressure, and pain. Prostaglandins are synthesized in cells throughout the body, including in the lining of the stomach, the lungs, and the reproductive organs. They are also produced in response to injury or infection, and are thought to play a role in the body's healing process. Prostaglandins are often used as medications to reduce inflammation and pain, and are also used to prevent blood clots and to induce labor in pregnant women.

... is used by bacteria, fungi, and a variety of other animals. Many of the uses of acetylcholine rely on its action ... Acetylcholine is the primary neurotransmitter of the parasympathetic nervous system. In the brain, acetylcholine functions as a ... In 1926, Loewi and E. Navratil deduced that the compound is probably acetylcholine, as vagusstoff and synthetic acetylcholine ... Nicotine binds to and activates nicotinic acetylcholine receptors, mimicking the effect of acetylcholine at these receptors. ...
An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of acetylcholine, a ... Acetylcholine receptor: PMAP The Proteolysis Map-animation Acetylcholine+Receptors at the U.S. National Library of Medicine ... Although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. ... Acetylcholine receptor modulators can be classified by which receptor subtypes they act on: Nicotinic acetylcholine receptors ...
Acetylcholine itself binds to both muscarinic and nicotinic acetylcholine receptors. As ionotropic receptors, nAChRs are ... Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. ... Nicotinic acetylcholine receptors, Ion channels, Autoantigens, Cell signaling, Acetylcholine receptors). ... The muscarinic acetylcholine receptor likewise gets its name from a chemical that selectively attaches to that receptor - ...
... s, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in ... The somatic nervous system uses a nicotinic receptor to acetylcholine at the neuromuscular junction. Muscarinic acetylcholine ... both releasing acetylcholine and expressing acetylcholine receptors. Both preganglionic sympathetic fibers and preganglionic ... where they are involved in the regulation of acetylcholine release. Muscarinic acetylcholine receptors belong to a class of ...
Varoqui H, Erickson JD (Nov 1996). "Active transport of acetylcholine by the human vesicular acetylcholine transporter". The ... "Search for the acetylcholine and vesamicol binding sites in vesicular acetylcholine transporter: the region around the lumenal ... Vesicular+Acetylcholine+Transporter at the U.S. National Library of Medicine Medical Subject Headings (MeSH) v t e (Articles ... Acetylcholine transport utilizes a proton gradient established by a vacuolar ATPase. PET imaging of the VAChT may provide ...
The muscarinic acetylcholine receptor M1, also known as the cholinergic receptor, muscarinic 1, is a muscarinic receptor that ... "Acetylcholine receptors (muscarinic): M1". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and ... Allard WJ, Sigal IS, Dixon RA (December 1987). "Sequence of the gene encoding the human M1 muscarinic acetylcholine receptor". ... Bonner TI, Buckley NJ, Young AC, Brann MR (July 1987). "Identification of a family of muscarinic acetylcholine receptor genes ...
The muscarinic acetylcholine receptor, also known as cholinergic/acetylcholine receptor M3, or the muscarinic 3, is a ... "Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor ... "Acetylcholine receptors (muscarinic): M3". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and ... acetylcholine bethanechol carbachol L-689,660 (mixed M1/M3 agonist) oxotremorine pilocarpine (in eye) muscarine atropine ...
The muscarinic acetylcholine receptor M2, also known as the cholinergic receptor, muscarinic 2, is a muscarinic acetylcholine ... "Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor ... "Acetylcholine receptors (muscarinic): M2". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and ... Obara K, Arai K, Miyajima N, Hatano A, Tomita Y, Takahashi K (June 2000). "Expression of m2 muscarinic acetylcholine receptor ...
"Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor ... The human muscarinic acetylcholine receptor M5, encoded by the CHRM5 gene, is a member of the G protein-coupled receptor ... Binding of the endogenous ligand acetylcholine to the M5 receptor triggers a number of cellular responses such as adenylate ... Muscarinic receptors mediate many of the effects of acetylcholine in the central and peripheral nervous system. The clinical ...
Activation of M4 receptors inhibits acetylcholine release in the striatum. The M2 subtype of acetylcholine receptor functions ... "Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor ... The muscarinic acetylcholine receptor M4, also known as the cholinergic receptor, muscarinic 4 (CHRM4), is a protein that, in ... acetylcholine carbachol oxotremorine LY-2033298 VU-0152100 (ML-108) VU-0152099 AFDX-384 (mixed M2/M4 antagonist, N-[2-[2-[( ...
Acetylcholine is a neuromodulator that is closely studied for its role in learning and memory; it is involved in the ... Homopentameric receptors with five acetylcholine binding sites contain two a-subunits (a2-a4 or a6) and two non-a-subunits (B2 ... The alpha-5 nicotinic acetylcholine receptor (α5 nAChR) also known as the α5 receptor is a type of ligand gated nicotinic ... Salas R, Orr-Urtreger A, Broide RS, Beaudet A, Paylor R, De Biasi M (May 2003). "The nicotinic acetylcholine receptor subunit ...
The protein encoded by this gene synthesizes the neurotransmitter acetylcholine. Acetylcholine acts at two classes of receptors ... The role of acetylcholine at the nicotinic receptor is still under investigation. It is likely implicated in the reward/ ... Choline Acetylcholine It is often used as an immunohistochemical marker for motor neurons (motoneurons). Mutants of ChAT have ... The concentrations of acetylcholine and ChAT are remarkably reduced in the cerebral neocortex and hippocampus. Although the ...
In particular, the activation of muscarinic acetylcholine receptor M2 and muscarinic acetylcholine receptor M4 inhibits ... Habibi M (2017). "Acetylcholine ☆". Reference Module in Neuroscience and Biobehavioral Psychology. Elsevier. doi:10.1016/b978-0 ... The mesolimbic pathway, which projects from the VTA to the nucleus accumbens, is also regulated by muscarinic acetylcholine ... Acetylcholine, and Orexin". In Sydor A, Brown RY (eds.). Molecular Neuropharmacology: A Foundation for Clinical Neuroscience ( ...
For example, mutants with fewer acetylcholine receptors may paralyze slower than wild type. It has been studied as a method to ... Levamisole works as a nicotinic acetylcholine receptor agonist that causes continued stimulation of the parasitic worm muscles ... Schedl Lab Protocol for gonad dissections Rand JB (January 2007). "Acetylcholine". WormBook: 1-21. doi:10.1895/wormbook.1.131.1 ... Levamisole acts as an acetylcholine receptor agonist, which leads to muscle contraction. Continuing activation leads to ...
"Acetylcholine". Neurosci.pharm, MBC 3320. Archived from the original on 2007-12-27. v t e (Nicotinic acetylcholine receptors, ... Acetylcholine Carbachol Suxamethonium α-Bungarotoxin α-Conotoxin Hexamethonium Pancuronium Tubocurarine Nicotinic acetylcholine ... The muscle-type nicotinic receptor is a type of nicotinic acetylcholine receptor consisting of the subunit combination (α1)2 ...
Acetylcholine (ACh) is an excitatory, small-molecule neurotransmitter involved in synaptic transmission at neuromuscular ... cite journal}}: Cite journal requires ,journal= (help) J. Rand (2007). "Acetylcholine". Stephen Gislason (1995). " ...
Acetylcholine also operates in many regions of the brain, but using different types of receptors, including nicotinic and ... For example, acetylcholine is eliminated by having its acetyl group cleaved by the enzyme acetylcholinesterase; the remaining ... "Acetylcholine Receptors". Ebi.ac.uk. Retrieved 25 August 2014. Schacter, Gilbert and Weger. Psychology.United States of America ... Acetylcholine was the first neurotransmitter discovered in the peripheral and central nervous systems. It activates skeletal ...
Neurotransmitter systems: 5-HT: serotonin; DA: dopamine; NE: noradrenalin; ACh: acetylcholine; Glu: glutamate; OXY: oxytocin; ... acetylcholine and neuropeptide systems, whereas the three emotionality-related traits emerge as a dysregulation of opioid ... This neurochemical component of the FET hypothesis was upgraded in 2015 by underlying a key role of acetylcholine and ... Differential regulation of fronto-executive function by the monoamines and acetylcholine. Cerebral Cortex 17 (Suppl 1):151-160 ...
Atropine blocks a subset of acetylcholine receptors known as muscarinic acetylcholine receptors (mAchRs), so that the buildup ... When acetylcholine binds to nicotinic receptors at the neuromuscular junction, it stimulates muscle contraction. To avoid a ... Accumulation of acetylcholine in the brain also causes neuronal excitotoxicity, due to activation of nicotinic receptors and ... VX blocks the action of AChE, resulting in an accumulation of acetylcholine in the space between the neuron and muscle cell. On ...
As muscarine works on the muscarinic acetylcholine receptor, the best comparison can be made with acetylcholine, which normally ... Muscarine mimics the action of the neurotransmitter acetylcholine by agonising muscarinic acetylcholine receptors. These ... Figure 3. Acetylcholine for comparison. The scheme below represents a very efficient way of the synthesis of (+)-muscarine ... Pure muscarine compared to pure acetylcholine is stated in most cases to be more potent, its action is always slower but longer ...
"Acetylcholine receptor anatomy". www.openanesthesia.org. Retrieved 2022-01-18. Cooper, Kathryn (October 2014). "The chemical ... AMPA Domoic acid Kainic acid NMDA Quinolinic acid Quisqualic acid Tetrazolylglycine Acetylcholine receptor agonists are drugs ... that activate the acetylcholine receptors. Anatoxin-a Pilocarpine Camphor injections for psychiatric treatment were inefficient ...
... acetylcholine (muscarinic effect); chemokines; lipid mediators of inflammation (e.g., prostaglandins, prostanoids, platelet- ...
Cholinergic neurons - acetylcholine. Acetylcholine is released from presynaptic neurons into the synaptic cleft. It acts as a ... Acetylcholine is synthesized from choline and acetyl coenzyme A. Adrenergic neurons - noradrenaline. Noradrenaline ( ... Weakness is typically caused by circulating antibodies that block acetylcholine receptors at the post-synaptic neuromuscular ... motor neurons in the spinal cord that release acetylcholine, and "inhibitory" spinal neurons that release glycine.[citation ...
High levels of Acetylcholine would thus allow for very rapid learning and remodelling of synaptic connections, with the ... Acetylcholine is proposed to facilitate the balance between memory storage and memory renewal, finding an optimal balance ... Acetylcholine thus modulates plasticity in the Hippocampus, Cerebral Cortex and Striatum to facilitate ideal learning ... Hasselmo, Michael (1993). "Acetylcholine and memory". Trends in Neurosciences. 16 (6): 218-222. doi:10.1016/0166-2236(93)90159- ...
Giancarlo Pepeu; Maria Grazia Giovannini (2004). "Acetylcholine: I. Muscarinic Receptors". In Gernot Riedel; Bettina Platt (eds ...
Its release is stimulated by gastrin and acetylcholine and inhibited by somatostatin. In the duodenum, gastric acid is ... October 15, 2012 "acetylcholine , Definition, Function, & Facts , Britannica". www.britannica.com. Retrieved 2021-12-13. " ... Nerve endings in the stomach secrete two stimulatory neurotransmitters: acetylcholine and gastrin-releasing peptide. Their ...
Brain acetylcholine and animal electrophysiology. In: Brain Acetylcholine and Neuropsychiatric Disease, K. L. Davis and P. A. ... Brain acetylcholine and seizures. In: Psychobiology of Convulsive Therapy, M. Fink, S. Kety, J. McGaugh and T. A. Willimas, Eds ... of the United States National Academy of Sciences and he is recipient of a Festschrift on neurobiology of acetylcholine, 1985. ...
The nicotinic acetylcholine receptor For women who are pregnant and already have MG, in a third of cases, they have been known ... The antibodies in MG attack a normal human protein, the nicotinic acetylcholine receptor, or a related protein called MuSK, a ... If the diagnosis is suspected, serology can be performed: One test is for antibodies against the acetylcholine receptor; the ... This is due to maternal antibodies that target an infant's acetylcholine receptors. In some cases, the mother remains ...
"Nicotinic acetylcholine receptors: Introduction". IUPHAR Database. International Union of Basic and Clinical Pharmacology. ... The alkaloid nicotine from tobacco binds directly to the body's Nicotinic acetylcholine receptors, accounting for its ...
NRG1 plays a role in synapse development, influencing the upregulation of acetylcholine receptor genes beneath the endplate ... Included in the family are heregulin; neu differentiation factor; acetylcholine receptor synthesis stimulator; glial growth ... or acetylcholine receptor inducing activity (ARIA) Type II NRG1; alternative name: Glial Growth Factor-2 (GGF2); Type III NRG1 ... after mammalian motor neurons have made synaptic contact with muscle fibres, hence its alternative name ARIA = Acetylcholine ...
Acetylcholine receptor antibody is a protein found in the blood of many people with myasthenia gravis. The antibody affects the ... Acetylcholine receptor antibody is a protein found in the blood of many people with myasthenia gravis. The antibody affects the ... An abnormal result means acetylcholine receptor antibody has been found in your blood. It confirms the diagnosis of myasthenia ... Normally, there is no acetylcholine receptor antibody (or less than 0.05 nmol/L) in the bloodstream. ...
Learn about alpha7 Nicotinic Acetylcholine Receptor at online-medical-dictionary.org ... alpha7 Nicotinic Acetylcholine Receptor. Synonyms. Nicotinic Acetylcholine Receptor alpha7. Receptor, alpha Bungarotoxin. ... A member of the NICOTINIC ACETYLCHOLINE RECEPTOR subfamily of the LIGAND-GATED ION CHANNEL family. It consists entirely of ...
Wilson AE Psychotropic drug influences on brain acetylcholine utilization Psychopharmacologia 1971 25:291-298 ... "Psychotropic drug influences on brain acetylcholine utilization" Psychopharmacologia. 1971;25:291-298. ...
... the key physiological effects that result from stimulation of muscarinic receptors by excessive amounts of acetylcholine. ... Instead, when acetylcholine attaches to the external part of the muscarinic receptor, the internal portion of the receptor ... Muscarinic acetylcholine receptors - like nicotinic receptors - are proteins that extend through the cell membrane from the ... the key physiological effects that result from stimulation of muscarinic receptors by excessive amounts of acetylcholine. ...
Acetylcholine receptor inhibitors. Class Summary. The most promising development for treating tardive dystonia and all other ... BTTA produces neuromuscular blockade by inhibiting the calcium ion-mediated release of acetylcholine at the motor nerve ... by Clostridium botulinum exert paralytic effects at the neuromuscular junction by inhibiting the release of acetylcholine, thus ...
Agrin-induced activation of acetylcholine receptor-bound Src family kinases requires Rapsyn and correlates with acetylcholine ... 1999) Nicotinic acetylcholine receptor at 4.6 A resolution: transverse tunnels in the channel wall. J Mol Biol 288:765-786. ... 2007) The dynamics of the rapsyn scaffolding protein at individual acetylcholine receptor clusters. J Biol Chem 282:9932-9940. ... 1991) Determination of the tyrosine phosphorylation sites of the nicotinic acetylcholine receptor. J Biol Chem 266:23784-23789. ...
Nicotinic acetylcholine receptor gene expression in developing chick autonomic ganglia. In: European journal of pharmacology, ... The developmental expression patterns of ten genes encoding nicotinic acetylcholine receptor subunits were analyzed using ...
Multiple Pharmacophores for the Selective Activation of Nicotinic α7-Type Acetylcholine Receptors. Nicole A. Horenstein, Fedra ... Multiple Pharmacophores for the Selective Activation of Nicotinic α7-Type Acetylcholine Receptors. Nicole A. Horenstein, Fedra ... Multiple Pharmacophores for the Selective Activation of Nicotinic α7-Type Acetylcholine Receptors. Nicole A. Horenstein, Fedra ... The activation of heteromeric and homomeric nicotinic acetylcholine receptors was studied in Xenopus laevis oocytes to identify ...
Acetylcholine Nicotinic Receptors B cells seek out TFH help for an interval derived from the quantity of antigen they ... Acetylcholine Nicotinic Receptors Several retrospective studies have helped support the 30% and 60% MaS thresholds for donor ... Acetylcholine Nicotinic Receptors Astrocytes of underneath coating aligned in parallel typically, whereas the very best ... Acetylcholine Nicotinic Receptors Thus, these results are mechanistically congruent using the marked aftereffect of FLAP ...
... acetylcholine), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules ... encoded search term (acetylcholine (Miochol E%2C)) and acetylcholine (Miochol E,) What to Read Next on Medscape ... acetylcholine chloride intraocular NO MONOGRAPH AVAILABLE AT THIS TIME USES: Consult your pharmacist. HOW TO USE: Consult your ...
Regulatory role of enteric mu and kappa opioid receptors in the release of acetylcholine and norepinephrine from guinea pig ... We examined the role of opioid receptor subtypes in the contraction and release of acetylcholine (ACh) and norepinephrine in ... Regulatory role of enteric mu and kappa opioid receptors in the release of acetylcholine and norepinephrine from guinea pig ... Regulatory role of enteric mu and kappa opioid receptors in the release of acetylcholine and norepinephrine from guinea pig ...
Current literature suggests involvement of nicotinic acetylcholine receptors (nAChRs) in major depression. However, it is ... Antidepressant-like effects of nicotinic acetylcholine receptor antagonists, but not agonists, in the mouse forced swim and ... Current literature suggests involvement of nicotinic acetylcholine receptors (nAChRs) in major depression. However, it is ...
Brown, J. L., & Wonnacott, S. (2014). Sazetidine-A activates and desensitizes native α7 nicotinic acetylcholine receptors. ... Sazetidine-A activates and desensitizes native α7 nicotinic acetylcholine receptors. / Brown, Jack L.; Wonnacott, Susan. In: ... The aim of this study was to investigate the ability of sazetidine-A, a novel partial agonist at α4β2 nicotinic acetylcholine ... Brown, JL & Wonnacott, S 2014, Sazetidine-A activates and desensitizes native α7 nicotinic acetylcholine receptors, ...
The IUPHAR/BPS Guide to Pharmacology. acetylcholine ligand page.
One chemical that may be required is acetylcholine. Acetylcholine is a brain chemical that is broadly important for cognition ... Acetylcholine boosts turtle sense of direction Daniel M. Vahaba 0000-0003-2960-3756 ... However, acetylcholine acts on a variety of receptors in the brain; therefore, it was unclear which one might be responsible ... They then administered a drug that would block the M1 receptor and prevent acetylcholine from contributing to the turtles ...
Dive into the research topics of Acetylcholine and lobster sensory neurones. Together they form a unique fingerprint. ...
Acetylcholine. An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of the ... Muscarinic acetylcholine receptor M5. External links. *Acetylcholine+Receptors at the US National Library of Medicine Medical ... nicotinic acetylcholine receptors (nAChR, also known as "ionotropic" acetylcholine receptors) are particularly responsive to ... muscarinic acetylcholine receptors (mAChR, also known as "metabotropic" acetylcholine receptors) are particularly responsive to ...
Acetylcholine is an essential neurotransmitter for learning, dreaming and memory making. ... SKU: N/A Categories: 3D Molecule Jewelry, Acetylcholine, Acetylcholine Jewellery in Stock, All, Bracelets, In Stock, Learning ... Home / All / In Stock / Acetylcholine Jewellery in Stock / Acetylcholine Charm Bracelet 18k Rose Gold or Gold Vermeil. ... Acetylcholine Charm Bracelet. Acetylcholine is an essential neurotransmitter for learning, dreaming and memory making. The ...
The M₁ muscarinic acetylcholine receptor (mAChR) is predominantly expressed in the brain where it plays a major role in ... Pharmacological and structure-function studies of M₁ muscarinic acetylcholine receptor allosteric modulation. ... have largely failed as they focused on targeting the acetylcholine (ACh) binding site, which is identical in all five mAChR ...
This test measures the concentration of an antibody in your blood that may mean you have the autoimmune disease myasthenia gravis.
Muscarinic Acetylcholine Receptor Modulators. MOD0025. VU 152100. M4 Muscarinic Receptor. 409351-28-6. 10 mg; 50 mg. Online ... Muscarinic Acetylcholine Receptor Modulators. MOD0026. VU 0238429. M5 Muscarinic Receptor. 1160247-92-6. 10 mg; 50 mg. Online ... Muscarinic Acetylcholine Receptor Modulators. MOD0027. VU 0365114. M5 Muscarinic Receptor. 1208222-39-2. 10 mg; 50 mg. Online ... Muscarinic Acetylcholine Receptor Modulators. MOD0028. VU 6008667. M5 Muscarinic Receptor. 2092923-21-0. 2 mg; 5 mg. Online ...
an optomization of acetylcholine sensore 2020. Home an optomization of acetylcholine sensore 2020 an optomization of ... An optimized acetylcholine sensor for monitoring in vivo cholinergic activity * Chronic hM3dq signaling in microglia ...
Acetylcholine (ACh) spasm provocation test - Diagnostics abroad - ⭐ Top Doctors ⚕️No. 1 Hospital Group in Italy Advanced ... The acetylcholine test allows to detect a spasm of the epicardial coronary arteries (the segment of the coronary tree visible ...
However, the cellular effects induced by muscarinic acetylcholine receptors (mAChRs) activation are poorly understood in the ... Hasselmo ME, McGaughy J: High acetylcholine levels set circuit dynamics for attention and encoding and low acetylcholine levels ... Distinct muscarinic acetylcholine receptor subtypes mediate pre- and postsynaptic effects in rat neocortex. *Sylvain Gigout1, ... Gigout, S., Jones, G.A., Wierschke, S. et al. Distinct muscarinic acetylcholine receptor subtypes mediate pre- and postsynaptic ...
Category: Acetylcholine Muscarinic Receptors. Eculizumab may be the first drug approved for the treatment of. Eculizumab may be ... Categorized as Acetylcholine Muscarinic Receptors Tagged CB-839 novel inhibtior, LIPG. Ischemic preconditioning (IPC) is ... Categorized as Acetylcholine Muscarinic Receptors Tagged ITGA3, MG-132 pontent inhibitor. Background Prenatally stressed ... Categorized as Acetylcholine Muscarinic Receptors Tagged FGS1, Pexidartinib cell signaling. Goals: Tumor-associated macrophages ...
Folgering H, Rutten J, Agoston S. Stimulation of Phrenic nerve activity by an acetylcholine releasing drug: 4-aminopyridine. ... Folgering, H., Rutten, J., & Agoston, S. (1979). Stimulation of Phrenic nerve activity by an acetylcholine releasing drug: 4- ... Folgering, H. ; Rutten, J. ; Agoston, S. / Stimulation of Phrenic nerve activity by an acetylcholine releasing drug : 4- ... Folgering, H, Rutten, J & Agoston, S 1979, Stimulation of Phrenic nerve activity by an acetylcholine releasing drug: 4- ...
They were then subjected to Annexin V apoptosis analysis. were increased in DSF-Cu+/Cu2+-treated OECM-1 cells ...
... no acetylcholine receptor (AChR) antibody exists in the bloodstream. Binding antibody is the most common antibody found in ... 1] Anti-acetylcholine receptor antibody forms a complex with acetylcholine receptors and increases its degradation by either ... encoded search term (Acetylcholine Receptor Antibody) and Acetylcholine Receptor Antibody What to Read Next on Medscape ... Acetylcholine Receptor Antibody Updated: Aug 11, 2014 * Author: Shivani Garg, MD, MBBS; Chief Editor: Eric B Staros, MD more... ...
... no acetylcholine receptor (AChR) antibody exists in the bloodstream. Binding antibody is the most common antibody found in ... 1] Anti-acetylcholine receptor antibody forms a complex with acetylcholine receptors and increases its degradation by either ... encoded search term (Acetylcholine Receptor Antibody) and Acetylcholine Receptor Antibody What to Read Next on Medscape ... Acetylcholine Receptor Antibody Updated: Aug 11, 2014 * Author: Shivani Garg, MD, MBBS; Chief Editor: Eric B Staros, MD more... ...
... Naveh Z. M ... Conformational changes in acetylcholine binding protein investigated by temperature accelerated molecular dynamics / Naveh, Z. ... Despite the large number of studies available on nicotinic acetylcholine receptors, a complete account of the mechanistic ... Despite the large number of studies available on nicotinic acetylcholine receptors, a complete account of the mechanistic ...
  • A member of the NICOTINIC ACETYLCHOLINE RECEPTOR subfamily of the LIGAND-GATED ION CHANNEL family . (online-medical-dictionary.org)
  • Muscarinic acetylcholine receptors - like nicotinic receptors - are proteins that extend through the cell membrane from the outside to the inside. (cdc.gov)
  • The developmental expression patterns of ten genes encoding nicotinic acetylcholine receptor subunits were analyzed using Northern blots and in situ hybridization in chick peripheral ganglia of neural crest, placodal and dual embryonic origin. (unige.ch)
  • The activation of heteromeric and homomeric nicotinic acetylcholine receptors was studied in Xenopus laevis oocytes to identify key structures of putative agonist molecules associated with the selective activation of homomeric α7 receptors. (aspetjournals.org)
  • Current literature suggests involvement of nicotinic acetylcholine receptors (nAChRs) in major depression. (nih.gov)
  • The aim of this study was to investigate the ability of sazetidine-A, a novel partial agonist at α4β2 nicotinic acetylcholine receptors (nAChRs), to affect the function of native α7 nAChRs in SH-SY5Y cells and primary cortical cultures. (bath.ac.uk)
  • Brown, JL & Wonnacott, S 2014, ' Sazetidine-A activates and desensitizes native α7 nicotinic acetylcholine receptors ', Neurochemical Research , vol. 40, no. 10, pp. 2047-2054. (bath.ac.uk)
  • Nicotinic acetylcholine receptors can be blocked by curare and toxins present in the venoms of snakes and shellfishes , like α-bungarotoxin . (wikidoc.org)
  • Assessment of nicotinic acetylcholine receptor subunit contributions to nicotine self-administration in mutant mice. (bvsalud.org)
  • Identify the key physiological effects that result from stimulation of muscarinic receptors by excessive amounts of acetylcholine. (cdc.gov)
  • Regulatory role of enteric mu and kappa opioid receptors in the release of acetylcholine and norepinephrine from guinea pig ileum. (aspetjournals.org)
  • Taken together, Roth and Krochmal's findings suggest that painted turtles require acetylcholine acting specifically on M1 receptors for both memorizing and recalling navigation routes. (biologists.com)
  • Like other transmembrane receptors , acetylcholine receptors are classified according to their "pharmacology", or according to their relative affinities and sensitivities to different molecules. (wikidoc.org)
  • Although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. (wikidoc.org)
  • muscarinic acetylcholine receptors ( mAChR , also known as " metabotropic " acetylcholine receptors) are particularly responsive to muscarine . (wikidoc.org)
  • Muscarinic acetylcholine receptors can be blocked by the drugs atropine and scopolamine . (wikidoc.org)
  • However, the cellular effects induced by muscarinic acetylcholine receptors (mAChRs) activation are poorly understood in the neocortex. (biomedcentral.com)
  • Anti-acetylcholine receptor antibody is found in 70-90% of patients with generalized acquired myasthenia gravis (MG). Lambert-Eaton syndrome is a close differential, as less than 13% of patients have clinical presentation similar to MG and antibodies against acetylcholine receptors in high titers. (medscape.com)
  • Acetylcholine receptor antibody is a protein found in the blood of many people with myasthenia gravis . (medlineplus.gov)
  • This article discusses the blood test for acetylcholine receptor antibody. (medlineplus.gov)
  • Normally, there is no acetylcholine receptor antibody (or less than 0.05 nmol/L) in the bloodstream. (medlineplus.gov)
  • An abnormal result means acetylcholine receptor antibody has been found in your blood. (medlineplus.gov)
  • More than 30% of patients with MG are seronegative (ie, anti-acetylcholine receptor antibody is absent in these patients). (medscape.com)
  • At the neuromuscular junction, the acetylcholine receptor (AChR) is specifically clustered in the postsynaptic membrane via interactions with rapsyn and other scaffolding proteins. (jneurosci.org)
  • An acetylcholine receptor (abbreviated AChR ) is an integral membrane protein that responds to the binding of the neurotransmitter acetylcholine . (wikidoc.org)
  • Normally, no acetylcholine receptor (AChR) antibody exists in the bloodstream. (medscape.com)
  • Acetylcholine is an essential neurotransmitter for learning, dreaming and memory making. (emily-alice.com)
  • The M₁ muscarinic acetylcholine receptor (mAChR) is predominantly expressed in the brain where it plays a major role in mediating cognitive processes such as learning and memory. (monash.edu)
  • Drug discovery efforts aimed at developing selective ligands for this receptor, both as therapeutics and as experimental tools, have largely failed as they focused on targeting the acetylcholine (ACh) binding site, which is identical in all five mAChR subtypes. (monash.edu)
  • Binding of acetylcholine to the N termini of each of the two alpha subunits results in the 15° rotation of all M2 helices. (wikidoc.org)
  • We examined the role of opioid receptor subtypes in the contraction and release of acetylcholine (ACh) and norepinephrine in longitudinal muscle-myenteric plexus preparations of the guinea pig ileum. (aspetjournals.org)
  • How disrupting cholinergic synaptic transmission could produce chronic illness is unclear, but recent research indicates that acetylcholine also mediates communication between axons and oligodendrocytes. (cdc.gov)
  • Excess acetylcholine produces a predictable cholinergic syndrome consisting of copious respiratory and oral secretions, diarrhea and vomiting, sweating, altered mental status, autonomic instability, and generalized weakness that can progress to paralysis and respiratory arrest. (cdc.gov)
  • nAChR is found at the edges of junctional folds at the neuromuscular junction on the postsynaptic side, and is activated by acetylcholine release across the synapse. (wikidoc.org)
  • [ 1 ] Therefore the reflex panel detects anti-acetylcholine receptor (blocking and binding) antibodies in the serum, if antibody level is greater than 0.4nmol/L, or antibody level is greater than 15% then modulating antibody is added. (medscape.com)
  • Inhibition of acetylcholinesterase leads , thereby leading to an accumulation of acetylcholine in the central and peripheral nervous system. (cdc.gov)
  • Instead, when acetylcholine attaches to the external part of the muscarinic receptor, the internal portion of the receptor releases large guanine nucleotide binding proteins (G-Proteins) (See note below), inside the cell. (cdc.gov)
  • Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect. (bvsalud.org)
  • BTTA produces neuromuscular blockade by inhibiting the calcium ion-mediated release of acetylcholine at the motor nerve terminals. (medscape.com)
  • Recently, Timothy Roth II (Franklin and Marshall College, USA) and Aaron Krochmal (Washington College, USA) found that acetylcholine is also important for painted turtles ( Chrysemys picta ) that are journeying to new water sources. (biologists.com)
  • Phenylephrine (Phe) and acetylcholine (Ach) dose -response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring . (bvsalud.org)
  • Acetylcholine is a brain chemical that is broadly important for cognition and appears to be particularly relevant for spatial navigation. (biologists.com)
  • They then administered a drug that would block the M1 receptor and prevent acetylcholine from contributing to the turtles' ability to recall the route that they had learned the previous year. (biologists.com)
  • The acetylcholine test allows to detect a spasm of the epicardial coronary arteries (the segment of the coronary tree visible at coronarography) or a spasm of the microcirculation (consisting of small vessels, not detectable with the current angiographic methods). (gsdinternational.com)
  • The stimulant action of acetylcholine and catecholamines on the uterus. (elsevierpure.com)
  • They are one of five muscarinic receptors that act to control the metabotropic functions of acetylcholine in the CNS. (tocris.com)
  • Identify the key physiological effects that result from stimulation of muscarinic receptors by excessive amounts of acetylcholine. (cdc.gov)
  • Muscarinic acetylcholine receptors - like nicotinic receptors - are proteins that extend through the cell membrane from the outside to the inside. (cdc.gov)
  • Nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that include muscle and neuronal nAChRs and receptors for GABA A , glycine, and serotonin. (jneurosci.org)
  • Anti-acetylcholine receptor antibody is found in 70-90% of patients with generalized acquired myasthenia gravis (MG). Lambert-Eaton syndrome is a close differential, as less than 13% of patients have clinical presentation similar to MG and antibodies against acetylcholine receptors in high titers. (medscape.com)
  • Mechanisms of steric and cooperative actions of alcuronium on cardiac muscarinic acetylcholine receptors. (aspetjournals.org)
  • Cholinergic nootropics target both the cholinergic system and the cholinergic receptors, as well as the acetylcholine neurotransmitter â this is central to the brainâ s ability to focus, learn, remember and remain coordinated. (hibhutan.com)
  • Nicotinic acetylcholine receptors (nAChRs) are present throughout the central nervous system and involved in a variety of physiological and behavioral functions. (oxfordre.com)
  • Nicotinic acetylcholine receptors are receptive to the presence of nicotine and acetylcholine and can be modulated through a variety of agonist and antagonist actions. (oxfordre.com)
  • Summary of work on this project as indicated on the report: 'Our aim is to study the distribution of nicotinic acetylcholine receptors in intact and cultured tissues of the peripheral and central nervous system in relationship to the development and function of synapses. (nih.gov)
  • and we have initiated work on the structural interaction between the cytoskeleton and nicotinic acetylcholine receptors in cultured skeletal muscle cells. (nih.gov)
  • Muscarinic acetylcholine receptors are transmembrane receptors providing several important physiological functions, including the regulation of heart rate, basal tension and smooth muscle motility of the respiratory tract, digestive tract and urogenital system. (knu.ua)
  • The research group of the Department of Molecular Biotechnology and Bioinformatics carries out a full cycle of targeted search and development using bioinformatics and chemoinformatics methods, as well as research and analysis of the biological activity of substances - selective agonists and antagonists of certain subtypes of muscarinic acetylcholine receptors. (knu.ua)
  • To date, new synthetic high-affinity selective low-molecular-weight antagonists of M3 subtype muscarinic acetylcholine receptors and agonists of M2 subtype receptors have been developed. (knu.ua)
  • Nicotinic acetylcholine receptors (nAChRs) are essential for cellular communication in higher organisms. (uni-muenchen.de)
  • Dr. Jerry Yakel is a neurobiologist studying acetylcholine receptors, which allow neurons to turn signals transmitted using the chemical acetylcholine into electrical messages. (nih.gov)
  • Because acetylcholine receptors are found on so many nerve cells, numerous neurological disorders can arise when they fail to work properly, including Alzheimer's, Parkinson's, and epilepsy. (nih.gov)
  • Borroni, M.V., Barrantes, F.J. Homomeric and heteromeric α7 nicotinic acetylcholine receptors in health and some central nervous system diseases [en línea]. (uca.edu.ar)
  • Abstract: Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels involved in the modulation of essential brain functions such as memory, learning, and attention. (uca.edu.ar)
  • This superfamily of allosteric transmembrane proteins includes the nicotinic acetylcholine (nAChR), serotonin 5-HT3, gamma-aminobutyric-acid (GABAA and GABAC) and glycine receptors. (nih.gov)
  • The neuronal nicotinic acetylcholine receptor channels (nAChRs) are expressed throughout the central and peripheral nervous system and are involved in a variety of normal brain functions including cognitive tasks, neuronal development, and mediating the rewarding effects of nicotine. (nih.gov)
  • of a larger protein called a neuronal nicotinic acetylcholine receptor (nAChR). (nih.gov)
  • The α7 subunit of the neuronal nicotinic acetylcholine receptor (nAChR) is abundantly expressed in hippocampus and is implicated in modulating neurotransmitter release and in binding α-bungarotoxin (α-BGT). (jneurosci.org)
  • the gamma (γ) protein component (subunit) of the acetylcholine receptor (AChR) protein. (nih.gov)
  • 1. Beeson D, Brydson M, Newsom-Davis J. (1989) Nucleotide sequence of human muscle acetylcholine receptor beta-subunit. (guidetopharmacology.org)
  • 1996) New mutations in acetylcholine receptor subunit genes reveal heterogeneity in the slow-channel congenital myasthenic syndrome. (guidetopharmacology.org)
  • 1996) A beta-subunit mutation in the acetylcholine receptor channel gate causes severe slow-channel syndrome. (guidetopharmacology.org)
  • 1999) Mutation causing congenital myasthenia reveals acetylcholine receptor beta/delta subunit interaction essential for assembly. (guidetopharmacology.org)
  • To investigate the relation between nicotinic acetylcholine receptor subunit (nAChR) genes and schizophrenia, and the relation between tag single nucleotide polymorphism (rs1317286, rs1044396, rs6494212, rs16969968, and rs684513) and schizophrenia in Han Chinese people. (psychiatryinvestigation.org)
  • Here we present the crystal structure of molluscan acetylcholine-binding protein (AChBP), a structural and functional homologue of the amino-terminal ligand-binding domain of an nAChR alpha-subunit. (nih.gov)
  • 1. Alex Nyporko, Olga Tsymbalyuk, Ivan Voiteshenko, Sergiy Starosyla, Mykola Protopopov, Volodymyr Bdzhola (2023) Computer-aided design of muscarinic acetylcholine receptor m3 inhibitors: promising compounds among trifluoromethyl containing hexahydropyrimidinones/thiones // Molecular Informatics Accepted Article. (knu.ua)
  • Cellular and humoral immunity to acetylcholine receptor in myasthenia gravis. (nih.gov)
  • The grant of the Ministry of Education and Science of Ukraine "Rational design of muscarinic acetylcholine receptor type 2 activators as potential components of acute myocardial infarction and wound therapy" (2023-2025). (knu.ua)
  • His group studies the structure, function and regulation of the Cys-loop ligand-gated ion channel superfamily, with a particular focus on the nicotinic acetylcholine receptor channels and their role in neurological disorders. (nih.gov)
  • Basal forebrain neurons control intracortical arterioles by releasing acetylcholine (Ach), which stimulates endothelial cells (ECs) to produce the vasodilating gasotransmitter, nitric oxide (NO). Surprisingly, the mechanism by which Ach induces NO synthesis in brain ECs is still unknown. (fupress.net)
  • Unexpectedly, two molecules of xanomeline were found to concomitantly bind to the monomeric M 4 mAChR, with one molecule bound in the orthosteric (acetylcholine-binding) site and a second molecule in an extracellular vestibular allosteric site. (rcsb.org)
  • Insecticidal spider toxins are high affinity positive allosteric modulators of the nicotinic acetylcholine receptor. (cipps.org.au)
  • 1986) Chromosomal localization of muscle nicotinic acetylcholine receptor genes in the mouse. (guidetopharmacology.org)
  • Inositol incorporation into phosphoinositides in retinal horizontal cells of Xenopus laevis: enhancement by acetylcholine, inhibition by glycine. (rupress.org)
  • Acetylcholine added to the culture medium enhances the incorporation of [2-3H]inositol into phosphoinositides in horizontal cells when retinas are incubated in the dark. (rupress.org)
  • Increased levels of choline then trigger the body to increase the production of acetylcholine. (hibhutan.com)
  • It has been well documented to increase levels of acetylcholine in the brain and it has synergistic effects with Piracetam, Aniracetam, and Oxiracetam. (hibhutan.com)
  • In addition the optimal doses of Vitamin D3 and Taurine may play an important role in the future treatment of Autism, Alzheimer's Disease and memory disturbances by significantly increasing Acetylcholine and DHEA levels, enhancing the excretion of toxic substances in the urine, as well as having an anticancer effect. (qxmd.com)
  • Will this kind of histone marking occur with other chemical messengers, such as dopamine and acetylcholine? (nih.gov)
  • First of all, into a chemical known as acetyl-COA, it breaks down and then, to make acetylcholine, it combines with choline. (hibhutan.com)
  • Acetylcholine (ACh) rechallenge may be a novel method to improve detection of coexisting coronary spasm endotypes, and at the same time, assess the treatment response to nitrate-based therapies, a new study suggests. (medscape.com)