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FAQAcetylcholine: 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.Receptors, Nicotinic: 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.Receptors, Cholinergic: 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.alpha7 Nicotinic Acetylcholine Receptor: 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.Bungarotoxins: 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.Torpedo: 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 Acetylcholine Transport Proteins: 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.Receptors, Muscarinic: 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.Nicotinic Antagonists: 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.Nicotinic Agonists: 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.Electric Organ: 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)Atropine: An alkaloid, originally from Atropa belladonna, but found in other plants, mainly SOLANACEAE. Hyoscyamine is the 3(S)-endo isomer of atropine.Nicotine: 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.Physostigmine: 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.Neuromuscular Junction: The synapse between a neuron and a muscle.Carbachol: A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.Tubocurarine: A neuromuscular blocker and active ingredient in CURARE; plant based alkaloid of Menispermaceae.Cholinergic Agents: 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.Muscarinic Antagonists: 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.Choline: 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.Cholinesterase Inhibitors: 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.Acetylcholinesterase: 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.Receptor, Muscarinic M2: 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.Vasodilation: The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.Muscarinic Agonists: 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.Receptor, Muscarinic M1: 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.Myasthenia Gravis: 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)Vasodilator Agents: Drugs used to cause dilation of the blood vessels.Receptor, Muscarinic M3: A subclass of muscarinic receptor that mediates cholinergic-induced contraction in a variety of SMOOTH MUSCLES.Parasympathomimetics: 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.Motor Endplate: 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.Muscles: Contractile tissue that produces movement in animals.Mecamylamine: 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.Choline O-Acetyltransferase: An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.Aconitine: 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.Nitroprusside: 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.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Conotoxins: 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)Cholinergic Agonists: Drugs that bind to and activate cholinergic receptors.AzocinesParasympatholytics: Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.Oxotremorine: A non-hydrolyzed muscarinic agonist used as a research tool.Cobra Neurotoxin Proteins: 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.Guinea Pigs: 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.Parasympathetic Nervous System: 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.Endothelium, Vascular: Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.Quinuclidinyl Benzilate: A high-affinity muscarinic antagonist commonly used as a tool in animal and tissue studies.Agrin: 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.Membrane Potentials: 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).Cholinergic Fibers: Nerve fibers liberating acetylcholine at the synapse after an impulse.Hexamethonium Compounds: Compounds containing the hexamethylenebis(trimethylammonium) cation. Members of this group frequently act as antihypertensive agents and selective ganglionic blocking agents.Muscle Contraction: 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.N-Methylscopolamine: A muscarinic antagonist used to study binding characteristics of muscarinic cholinergic receptors.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Hemicholinium 3: 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-beta-Erythroidine: 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.Cholinergic Antagonists: Drugs that bind to but do not activate CHOLINERGIC RECEPTORS, thereby blocking the actions of ACETYLCHOLINE or cholinergic agonists.Muscle Denervation: The resection or removal of the innervation of a muscle or muscle tissue.Bicyclo Compounds, Heterocyclic: 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)Scopolamine Hydrobromide: 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.Neostigmine: 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.Electrophorus: 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.Synaptic Transmission: 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.Muscle, Smooth: 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)QuinolizinesGallamine Triethiodide: 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)Receptor, Muscarinic M4: 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.Iontophoresis: 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.Nitric Oxide: 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.Neurons: 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.Decamethonium Compounds: Compounds that contain the decamethylenebis(trimethyl)ammonium radical. These compounds frequently act as neuromuscular depolarizing agents.Pirenzepine: 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.Calcium: 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.Norepinephrine: 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.Amphibian Venoms: 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.Dimethylphenylpiperazinium Iodide: 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.Synaptic Membranes: 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.Xenopus laevis: 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.Ion Channels: 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.Ileum: The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.Electrophysiology: 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.Rats, Sprague-Dawley: 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.Curare: 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.Muscarine: 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.Muscle Relaxation: That phase of a muscle twitch during which a muscle returns to a resting position.Hexamethonium: 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.Neurotransmitter Agents: 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.Myasthenic Syndromes, Congenital: 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)Receptor, Muscarinic M5: 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.Kinetics: The rate dynamics in chemical or physical systems.Ganglia, Autonomic: 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.Microdialysis: 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, Parasympathetic: 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.Potassium: 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.Patch-Clamp Techniques: 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.CholinesterasesNerve Endings: 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.Piperidines: A family of hexahydropyridines.Biological Factors: Endogenously-synthesized compounds that influence biological processes not otherwise classified under ENZYMES; HORMONES or HORMONE ANTAGONISTS.Oocytes: 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).Forearm: Part of the arm in humans and primates extending from the ELBOW to the WRIST.Pyridines: Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.Receptor Aggregation: Chemically stimulated aggregation of cell surface receptors, which potentiates the action of the effector cell.Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.Tetrodotoxin: 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.Synapses: 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.Diaphragm: 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.omega-N-Methylarginine: A competitive inhibitor of nitric oxide synthetase.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cells, Cultured: 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.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Vasoconstriction: The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.Cholinergic Neurons: Neurons whose primary neurotransmitter is ACETYLCHOLINE.Nitroarginine: 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)Methacholine Compounds: A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).Rabbits: 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.Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Amino Acid Sequence: 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.Ganglionic Stimulants: 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.Serotonin: 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.Histamine: 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.Synaptosomes: 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.Neuromuscular Depolarizing Agents: 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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Bradykinin: 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.Binding, Competitive: 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.Molecular Sequence Data: 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.Cats: 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)Quaternary Ammonium Compounds: 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.Xenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Galantamine: 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.Snakes: Limbless REPTILES of the suborder Serpentes.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Anabasine: A piperidine botanical insecticide.Brain: 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.Nitroglycerin: A volatile vasodilator which relieves ANGINA PECTORIS by stimulating GUANYLATE CYCLASE and lowering cytosolic calcium. It is also sometimes used for TOCOLYSIS and explosives.Mesenteric Arteries: Arteries which arise from the abdominal aorta and distribute to most of the intestines.Proadifen: An inhibitor of drug metabolism and CYTOCHROME P-450 ENZYME SYSTEM activity.Vasomotor System: The neural systems which act on VASCULAR SMOOTH MUSCLE to control blood vessel diameter. The major neural control is through the sympathetic nervous system.Vagus Nerve: 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).Ganglionic Blockers: 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.Potassium Chloride: 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.Dogs: 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)Myenteric Plexus: 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)Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Alkaloids: 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)Nitric Oxide Synthase: An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.Paraoxon: An organophosphate cholinesterase inhibitor that is used as a pesticide.AzetidinesAorta, Thoracic: The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.Radioligand Assay: Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).NG-Nitroarginine Methyl Ester: A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.Rana pipiens: 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.Arginine: An essential amino acid that is physiologically active in the L-form.Indomethacin: 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.TritiumDrug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.QuinuclidinesCell Line: Established cell cultures that have the potential to propagate indefinitely.Phenylephrine: An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.Coronary Vessels: The veins and arteries of the HEART.Ion Channel Gating: 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.Neuromuscular Blocking Agents: 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.Neurotoxins: 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.Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.Macromolecular Substances: 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.Ligands: 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)Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Allosteric Regulation: 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.Hippocampus: 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.Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Substance P: 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.Chick Embryo: 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.Arterioles: The smallest divisions of the arteries located between the muscular arteries and the capillaries.Sweat Glands: Sweat-producing structures that are embedded in the DERMIS. Each gland consists of a single tube, a coiled body, and a superficial duct.Dopamine: 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.Cerebral Cortex: 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.Myasthenia Gravis, Autoimmune, Experimental: 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)Coronary Vasospasm: Spasm of the large- or medium-sized coronary arteries.Ganglia, Sympathetic: 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.Benzylidene Compounds: Compounds containing the PhCH= radical.QuinoxalinesRats, Inbred Strains: 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.Anura: 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.Phencyclidine: 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.Isoproterenol: 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.Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.Fishes: A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.Motor Neurons: Neurons which activate MUSCLE CELLS.Arecoline: 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.Pilocarpine: A slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma.Muscle, Skeletal: 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.Protein Binding: 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.Nootropic Agents: 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.Procaine: 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).Cobra Venoms: 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.Stimulation, Chemical: 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.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
(1/8871) Inhibitory innervation of cat sphincter of Oddi.
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)
(2/8871) 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.
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)
(3/8871) Modulation of long-term synaptic depression in visual cortex by acetylcholine and norepinephrine.
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)
(4/8871) Endothelial function in Marfan syndrome: selective impairment of flow-mediated vasodilation.
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)
(5/8871) Adrenoreceptors of the guinea-pig urinary bladder.
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)
(6/8871) Calcium responses induced by acetylcholine in submucosal arterioles of the guinea-pig small intestine.
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)
(7/8871) Somatostatin induces hyperpolarization in pancreatic islet alpha cells by activating a G protein-gated K+ channel.
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)
(8/8871) Inhibition of endothelium-dependent hyperpolarization by endothelial prostanoids in guinea-pig coronary artery.
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)
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)
(2/8871) 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.
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)
(3/8871) Modulation of long-term synaptic depression in visual cortex by acetylcholine and norepinephrine.
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)
(4/8871) Endothelial function in Marfan syndrome: selective impairment of flow-mediated vasodilation.
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)
(5/8871) Adrenoreceptors of the guinea-pig urinary bladder.
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)
(6/8871) Calcium responses induced by acetylcholine in submucosal arterioles of the guinea-pig small intestine.
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)
(7/8871) Somatostatin induces hyperpolarization in pancreatic islet alpha cells by activating a G protein-gated K+ channel.
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)
(8/8871) Inhibition of endothelium-dependent hyperpolarization by endothelial prostanoids in guinea-pig coronary artery.
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)
Acetylcholinesterase
For acetylcholine esterase (AChE), reversible inhibitors are those that do not irreversibly bond to and decactivate AChE. Drugs ... It is an enzyme that catalyzes the breakdown of acetylcholine and of some other choline esters that function as ... It has a very high catalytic activity - each molecule of AChE degrades about 25000 molecules of acetylcholine (ACh) per second ... The esteratic subsite, where acetylcholine is hydrolyzed to acetate and choline, contains the catalytic triad of three amino ...
Tubocurarine chloride
Without intervention, acetylcholine (ACh) in the peripheral nervous system activates skeletal muscles. Acetylcholine is ... Tubocurarine chloride acts as an antagonist for the nicotinic acetylcholine receptor (nAChr), meaning it blocks the receptor ... α-latrotoxin causes the release of neurotransmitters into the synaptic gap, including acetylcholine. Bites are usually not ... Bowman WC, Webb SN (1972). "Neuromuscular blocking and ganglion blocking activities of some acetylcholine antagonists in the ...
Neuromuscular junction
Acetylcholine diffuses into the synaptic cleft and can bind to the nicotinic acetylcholine receptors on the motor endplate, ... Acetylcholine is a neurotransmitter synthesized from dietary choline and acetyl-CoA (ACoA), and is involved in the stimulation ... Toxins are also used to determine the location of acetylcholine receptors at the neuromuscular junction. α-Bungarotoxin is a ... Botulinum toxin (aka botulinum neurotoxin, BoNT, and sold under the trade name Botox) inhibits the release of acetylcholine at ...
Nicotinic agonist
A nicotinic agonist is a drug that mimics the action of acetylcholine (ACh) at nicotinic acetylcholine receptors (nAChRs). The ... The development of nicotinic acetylcholine receptor agonists has come a long way since then. The nicotinic acetylcholine ... Agonist Muscarinic acetylcholine receptor Muscarinic agonist Muscarinic antagonist Nicotinic acetylcholine receptor Nicotinic ... Acetylcholine on the other hand induced a much longer opening time of the receptor though anatoxin is more potent. The results ...
Acetylcholine
... is now used by bacteria, fungi, and a variety of other animals. Interestingly, many of the uses of acetylcholine ... Nicotine binds to and activates nicotinic acetylcholine receptors, mimicking the effect of acetylcholine at these receptors. ... Substances that interfere with acetylcholine activity are called anticholinergics. Acetylcholine is the neurotransmitter used ... and allow for acetylcholine to dynamically regulate physiological processes. Acetylcholine is synthesized in certain neurons by ...
Acetylcholine receptor
An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of acetylcholine, a ... Although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. ... Acetylcholine receptor: PMAP The Proteolysis Map-animation Acetylcholine Receptors at the US National Library of Medicine ... Nicotinic acetylcholine receptors (nAChR, also known as "ionotropic" acetylcholine receptors) are particularly responsive to ...
Nicotinic acetylcholine receptor
Acetylcholine itself binds to both muscarinic and nicotinic acetylcholine receptors. As ionotropic receptors, nAChRs are ... Nicotinic acetylcholine receptors, or nAChRs, are receptor proteins that respond to the neurotransmitter acetylcholine. ... The muscarinic acetylcholine receptor likewise gets its name from a chemical that selectively attaches to that receptor - ... In muscle-type nAChRs, the acetylcholine binding sites are located at the α and either ε or δ subunits interface. In neuronal ...
Vesicular acetylcholine transporter
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 ... Acetylcholine transport utilizes a proton gradient established by a vacuolar ATPase. This gene is located within the first ... Vesicular Acetylcholine Transporter at the US National Library of Medicine Medical Subject Headings (MeSH). ...
Muscarinic acetylcholine receptor
... s, or mAChRs, are acetylcholine receptors that form G protein-receptor complexes in the cell ... The somatic nervous system uses a nicotinic receptor to acetylcholine at the neuromuscular junction. Muscarinic acetylcholine ... where they are involved in the regulation of acetylcholine release. Muscarinic acetylcholine receptors belong to a class of ... Here acetylcholine is again used as a neurotransmitter, and muscarinic receptors form the principal receptors on the innervated ...
Muscarinic acetylcholine receptor M1
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 (1988). "Sequence of the gene encoding the human M1 muscarinic acetylcholine receptor". Nucleic ... Ishizaka N, Noda M, Yokoyama S, Kawasaki K, Yamamoto M, Higashida H (1998). "Muscarinic acetylcholine receptor subtypes in the ...
Muscarinic acetylcholine receptor M3
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) atropine hyoscyamine ...
Muscarinic acetylcholine receptor M2
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 (2000). "Expression of m2 muscarinic acetylcholine receptor mRNA ...
Muscarinic acetylcholine receptor M4
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-[( ...
Muscarinic acetylcholine receptor M5
1999). "Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine ... The human muscarinic acetylcholine receptor M5, encoded by the CHRM5 gene, is a member of the G protein-coupled receptor ... Bonner TI, Young AC, Brann MR, Buckley NJ (1990). "Cloning and expression of the human and rat m5 muscarinic acetylcholine ... Binding of the endogenous ligand acetylcholine to the M5 receptor triggers a number of cellular responses such as adenylate ...
Choline acetyltransferase
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 ...
Excitatory synapse
J. Rand (2007). "Acetylcholine". Stephen Gislason (1995). "Neurotransmitter - Serotonin". Brain Mind Center at Alpha Online. R ... Acetylcholine (ACh) is an excitatory, small-molecule neurotransmitter involved in synaptic transmission at neuromuscular ...
Neurotransmitter
Acetylcholine also operates in many regions of the brain, but using different types of receptors, including nicotinic and ... "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 ... Nicotine, a compound found in tobacco, is a direct agonist of most nicotinic acetylcholine receptors, mainly located in ...
Functional Ensemble of Temperament
Neurotransmitter systems: 5-HT: serotonin; DA: dopamine; NE: noradrenalin; ACh: acetylcholine; Glu: glutamate; GH: Growth ... 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 ...
Neuron
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. GABAergic neurons-gamma aminobutyric acid. GABA is one of two ... 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. The ...
Metalearning (neuroscience)
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. Retrieved 2013-08-04. Doya, K. (2002). " ...
Alex Karczmar
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. ...
Neuregulin
ARIA 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 name ARIA = Acetylcholine Receptor ...
Parasympathetic nervous system
"Nicotinic acetylcholine receptors" (PDF). www.ucl.ac.uk/. University College London. Retrieved 4 March 2015. ... The net effect of innervated M3 receptors on blood vessels is vasodilation, as acetylcholine causes endothelial cells to ... The parasympathetic nervous system uses chiefly acetylcholine (ACh) as its neurotransmitter, although peptides (such as ...
Nicotine
Acetylcholine released by preganglionic sympathetic fibers of these nerves acts on nicotinic acetylcholine receptors, causing ... Nicotine acts as an agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits ( ... By binding to nicotinic acetylcholine receptors in the brain, nicotine elicits its psychoactive effects and increases the ... Additionally, specific types of nicotinic acetylcholine receptors- eg, alpha 7 receptors, which are stimulated by nicotine-are ...
Phantasmidine
336-337). Phantasmidine is a nicotinic agonist that acts at acetylcholine receptors. It mimics the effects of acetylcholine on ... This influx of positive charge induces the release of acetylcholine into the body to interact with the parasympathetic nervous ... Phantasmidine is characterized in the same class as epibatidine, which is a similar nicotinic acetylcholine agonist derived ... Phantasmidine is selective for nicotinic acetylcholine receptors (nAChR) containing ß4 subunits; however, responses in ...
M3R - Muscarinic Acetylcholine Receptor | AcronymFinder
M3R stands for Muscarinic Acetylcholine Receptor. M3R is defined as Muscarinic Acetylcholine Receptor somewhat frequently. ... Reconstitution of the muscarinic acetylcholine receptor.. Modulation of [[sup.3]H]-8-OH-DPAT binding to rat brain membranes by ... About M1 Receptors M1 muscarinic acetylcholine receptors are Gq-coupled receptors known to be important for learning and memory ... Muscarinic acetylcholine receptor subtypes in cerebral cortex and hippocampus.. Reversible acetylcholinesterase inhibitory ...
https://www.acronymfinder.com/Muscarinic-Acetylcholine-Receptor-
Anti-Nicotinic Acetylcholine Receptor beta antibody (ab66429) References
References for Abcam's Anti-Nicotinic Acetylcholine Receptor beta antibody (ab66429). Please let us know if you have used this ...
http://www.abcam.com/nicotinic-acetylcholine-receptor-beta-antibody-ab66429-references.html
British Library EThOS: Molecular pharmacological characterisation of neuronal nicotinic acetylcholine receptors
Neuronal nicotinic acetylcholine receptors (nAChRs) are excitatory ligand‐gated ion channels that perform important roles ... increase the receptor's sensitivity to agonist acetylcholine whereas negative allosteric modulators (NAMs) decrease sensitivity ...
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625384 British Library EThOS: Molecular and cell biological characterisation of neuronal nicotinic acetylcholine receptors
Molecular and cell biological characterisation of neuronal nicotinic acetylcholine receptors (nAChRs) provides an insight into ...
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409635
Muscarinic acetylcholine receptor M1
G-protein coupled acetylcholine receptor signaling pathway 15 adenylate cyclase-inhibiting G-protein coupled acetylcholine ... Crystal structures of the M1 and M4 muscarinic acetylcholine receptors.. 26481978. 2015. The effect of a muscarinic receptor 1 ... Molecular determinants of allosteric modulation at the M1 muscarinic acetylcholine receptor.. 24430298. 2014. CHRM2 but not ... The functional diversity of these receptors is defined by the binding of acetylcholine and includes cellular responses such as ...
https://pharos.nih.gov/idg/targets/P11229 Anti-Vesicular Acetylcholine Transporter抗体(ab31544)
Vesicular Acetylcholine Transporter羊多克隆抗体可与大鼠, 豚鼠样本反应并经WB, IHC实验严格验证 ... Primary: Anti-Vesicular Acetylcholine Transporter antibody (ab31544) diluted 1:1000 incubated overnight, washed 3 x 10 mins. ... Immunohistochemical analysis of Vesicular Acetylcholine Transporter in guinea pig gut. Method: Guinea Pig Ileum removed and ... Solute carrier family 18 (vesicular acetylcholine) member 3 antibody. *Solute carrier family 18
http://www.abcam.cn/vesicular-acetylcholine-transporter-antibody-ab31544.html Anti-Nicotinic Acetylcholine Receptor beta抗体[B3]
Nicotinic Acetylcholine Receptor beta小鼠单克隆抗体[B3](ab11150)可与人样本反应并经WB, IP, IHC, Flow Cyt实验 ... Anti-Nicotinic Acetylcholine Receptor beta抗体[B3]. 参阅全部 Nicotinic Acetylcholine Receptor beta 一抗. ... After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to ... Defects in CHRNB1 are a cause of congenital myasthenic syndrome with acetylcholine receptor
http://www.abcam.cn/nicotinic-acetylcholine-receptor-beta-antibody-b3-ab11150.html
An HPLC assay for the norditerpenoid alkaloid methyllycaconitine, a potent nicotinic acetylcholine receptor antagonist. -...
The extremely potent and selective nicotinic acetylcholine receptor antagonist methyllycaconitine, MLA, and related ... An HPLC assay for the norditerpenoid alkaloid methyllycaconitine, a potent nicotinic acetylcholine receptor antagonist. ... An HPLC assay for the norditerpenoid alkaloid methyllycaconitine, a potent nicotinic acetylcholine receptor antagonist. ... The extremely potent and selective nicotinic acetylcholine receptor antagonist methyllycaconitine, MLA, and related ...
https://pharm.ox.ac.uk/publications/677875
Uncovering the lipidic basis for the preparation of functional nicotinic acetylcholine receptor detergent complexes for...
Uncovering the lipidic basis for the preparation of functional nicotinic acetylcholine receptor detergent complexes for ...
https://dire.upr.edu/handle/11721/1571 Biophysical and ion channel functional characterization of the Torpedo californica nicotinic acetylcholine receptor in varying...
The nicotinic acetylcholine receptor (nAChR) of Torpedo electric rays has been extensively characterized over the last three ... Biophysical and ion channel functional characterization of the Torpedo californica nicotinic acetylcholine receptor in varying ...
https://dire.upr.edu/handle/11721/1565
Neuronal Acetylcholine Receptor Subunit Alpha 7 (CHRNA7) - Pipeline Review, H2 Industry Forecast by Regions, Type and...
The report provides comprehensive information on the Neuronal Acetylcholine Receptor Subunit Alpha 7 (CHRNA7) , targeted ... Neuronal Acetylcholine Receptor Subunit Alpha 7 (CHRNA7) - Pipeline Review, H2 2016', provides in depth analysis on Neuronal ... Acetylcholine Receptor Subunit Alpha 7 (CHRNA7) targeted pipeline therapeutics. ... Neuronal Acetylcholine Receptor Subunit Alpha 7 (CHRNA7) - Pipeline Review, H2 Industry Forecast by Regions, Type and ...
https://researchdrive.wordpress.com/2017/02/20/neuronal-acetylcholine-receptor-subunit-alpha-7-chrna7-pipeline-review-h2-industry-forecast-by-regions-type-and-application-report-to-2014-2020/
CMU Intellectual Repository: A novel in vitro potency assay of antisera against Thai Naja kaouthia based on nicotinic...
A novel in vitro potency assay of antisera against Thai Naja kaouthia based on nicotinic acetylcholine receptor binding. ... of elapid snakes with purified Torpedo californica nicotinic acetylcholine receptor (nAChR). The potency of an antivenom is ...
http://cmuir.cmu.ac.th/jspui/handle/6653943832/40073/
Miochol-E (acetylcholine)
Acetylcholine is a compound produced naturally by the body's nervous system. ... Miochol-E solution for intraocular use contains the active ingredient acetylcholine. ... Miochol-E (acetylcholine). Miochol-E solution for intraocular use contains the active ingredient acetylcholine. Acetylcholine ... Acetylcholine is a compound produced naturally by the body's nervous system.. When applied to the eye, acetylcholine stimulates ...
https://www.netdoctor.co.uk/medicines/eye-care/a7128/miochol-e-acetylcholine/ Template:Acetylcholine receptor modulators - Wikipedia
See also: Receptor/signaling modulators • Nicotinic acetylcholine receptor modulators • Acetylcholine metabolism/transport ... See also: Receptor/signaling modulators • Muscarinic acetylcholine receptor modulators • Acetylcholine metabolism/transport ... Acetylcholine receptor modulators,state=autocollapse}}. *shows the template collapsed to the title bar if there is a {{navbar}} ... Acetylcholine receptor modulators,state=collapsed}}. to show the template collapsed, i.e., hidden apart from its title bar ...
https://en.wikipedia.org/wiki/Template:Cholinergics
acetylcholine | Journal of Neuroscience
Synaptic Release of Acetylcholine Rapidly Suppresses Cortical Activity by Recruiting Muscarinic Receptors in Layer 4 Rajan ...
https://www.jneurosci.org/keyword/acetylcholine
Category:Acetylcholine receptor - Wikimedia Commons
Media in category "Acetylcholine receptor". The following 16 files are in this category, out of 16 total. ... Receptor de acetilcolina (es); receptor d'acetilcolina (ca); Acetylcholinrezeptoren (de); Acetylcholine receptor (en-gb); ... Acetylcholine receptor (en-ca); acetylcholinový receptor (cs); Recettore colinergico (it); récepteur cholinergique (fr); ... acetylcholine receptor (en); مستقبل الأستيل كولين (ar); Υποδοχέας ακετυλοχολίνης (el); Ацетилхолински рецептор (mk) ...
https://commons.wikimedia.org/wiki/Category:Acetylcholine_receptor
Acetylcholine | ThinkFirst
Help us teach kids of all ages how to prevent traumatic brain and spinal cord injuries! The ThinkFirst Foundation is a 501c3 nonprofit organization. Donate ...
http://www.thinkfirst.org/acetylcholine Acetylcholine - Wikipedia
Acetylcholine. Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals, ... Acetylcholine is now used by bacteria, fungi, and a variety of other animals. Interestingly, many of the uses of acetylcholine ... 3) Acetylcholine is released into the synaptic cleft. (4) Acetylcholine binds to postsynaptic receptors. (5) This binding ... Acetylcholine processing in a synapse. After release acetylcholine is broken down by the enzyme acetylcholinesterase. ...
https://en.m.wikipedia.org/wiki/Acetylcholine Acetylcholine Receptor (AChR) Antibody
AChR antibodies are autoantibodies that mistakenly target proteins called acetylcholine receptors that are located on skeletal ... An acetylcholine receptor (AChR) antibody test is used to help diagnose myasthenia gravis (MG), an autoimmune disease that ... Acetylcholine receptors function as "docking stations" for acetylcholine, a chemical substance (neurotransmitter) that ... where it stimulates the release of acetylcholine. Acetylcholine travels across a microscopic gap between the nerve ending and a ...
https://labtestsonline.org/tests/acetylcholine-receptor-achr-antibody
Acetylcholine
... Systematic (IUPAC) name 2-acetoxy-N,N,N-trimethylethanaminium Identifiers CAS number 51-84-3 ATC ... Main article: Acetylcholine receptor. There are two main classes of acetylcholine receptor (AChR), nicotinic acetylcholine ... When acetylcholine binds to acetylcholine receptors on skeletal muscle fibers, it opens ligand gated sodium channels in the ... Blocking, hindering or mimicking the action of acetylcholine has many uses in medicine. Drugs acting on the acetylcholine ...
http://www.bionity.com/en/encyclopedia/Acetylcholine.html
- Muscarinic acetylcholine receptor subtypes in cerebral cortex and hippocampus. (acronymfinder.com)
- Reconstitution of the muscarinic acetylcholine receptor . (acronymfinder.com)
- FIGURE 3 OMITTED] [FIGURE 4 OMITTED] An important role of parasympathetic cholinergic neurons and postsynaptic muscarinic acetylcholine receptors in the contraction of gastric smooth muscle has been provided in functional studies (Makhlouf and Murthy, 2006). (acronymfinder.com)
- FIGURE 5 OMITTED] [FIGURE 6 OMITTED] The present study further investigated the potential involvement of muscarinic acetylcholine receptors . (acronymfinder.com)
- About M1 Receptors M1 muscarinic acetylcholine receptors are Gq-coupled receptors known to be important for learning and memory. (acronymfinder.com)
- When applied to the eye, acetylcholine stimulates receptors called cholinoceptors that are present in the circular muscle of the iris (the coloured part of the eye). (netdoctor.co.uk)
- Drugs that act on muscarinic acetylcholine receptors , such as atropine , can be poisonous in large quantities, but in smaller doses they are commonly used to treat certain heart conditions and eye problems. (wikipedia.org)
- The addictive qualities of nicotine are derived from its effects on nicotinic acetylcholine receptors in the brain. (wikipedia.org)
- Like many other biologically active substances, acetylcholine exerts its effects by binding to and activating receptors located on the surface of cells. (wikipedia.org)
- Nicotinic acetylcholine receptors are ligand-gated ion channels permeable to sodium , potassium , and calcium ions. (wikipedia.org)
- Muscarinic acetylcholine receptors have a more complex mechanism, and affect target cells over a longer time frame. (wikipedia.org)
- Acetylcholine receptors function as "docking stations" for acetylcholine, a chemical substance (neurotransmitter) that transmits messages between nerve cells. (labtestsonline.org)
- When it reaches the muscle fiber, it binds to one of many acetylcholine receptors and activates it, initiating muscle contraction. (labtestsonline.org)
- AChR antibodies impede communication between nerves and skeletal muscles, inhibit muscle contraction, and cause rapid muscle fatigue by preventing activation of the acetylcholine receptors. (labtestsonline.org)
- Blocking antibodies may sit on the receptors, preventing acetylcholine from binding. (labtestsonline.org)
- When acetylcholine binds to acetylcholine receptors on skeletal muscle fibers, it opens ligand gated sodium channels in the cell membrane . (bionity.com)
- Muscarinic acetylcholine receptors play a key role in the regulation of signal transduction in the central and peripheral nervous systems. (els.net)
- Nathanson, Neil M(Jan 2006) Muscarinic Acetylcholine Receptors. (els.net)
- Like other transmembrane receptors , acetylcholine receptors are classified according to their "pharmacology", or according to their relative affinities and sensitivities to different molecules. (bionity.com)
- Although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. (bionity.com)
- muscarinic acetylcholine receptors ( mAChR , also known as " metabotropic " acetylcholine receptors) are particularly responsive to muscarine . (bionity.com)
- Nicotinic acetylcholine receptors can be blocked by curare and toxins present in the venoms of snakes and shellfishes, like α-bungarotoxin. (bionity.com)
- Muscarinic acetylcholine receptors can be blocked by the drugs atropine and scopolamine . (bionity.com)
- Binding" antibodies attach to the acetylcholine receptors on nerve cells and may initiate an inflammatory reaction that destroys them. (labcorp.com)
- Acetylcholine - the natural agonist of muscarinic and nicotinic receptors. (wikipedia.org)
- Peripheral autonomic fibers (sympathetic and parasympathetic fibers) are categorized anatomically as either preganglionic or postganglionic fibers, then further generalized as either adrenergic fibers, releasing noradrenaline, or cholinergic fibers, both releasing acetylcholine and expressing acetylcholine receptors. (wikipedia.org)
- Here acetylcholine is again used as a neurotransmitter, and muscarinic receptors form the principal receptors on the innervated tissue. (wikipedia.org)
- Muscarinic acetylcholine receptors are also present and distributed throughout the local nervous system, in post-synaptic and pre-synaptic positions. (wikipedia.org)
- It is known that muscarinic acetylcholine receptors also appear on the pre-synaptic membrane of somatic neurons in the neuro-muscular junction, where they are involved in the regulation of acetylcholine release. (wikipedia.org)
- Muscarinic acetylcholine receptors belong to a class of metabotropic receptors that use G proteins as their signaling mechanism. (wikipedia.org)
- Muscarinic acetylcholine receptors: mutant mice provide new insights for drug development. (ebi.ac.uk)
- Distinct primary structures, ligand-binding properties and tissue-specific expression of four human muscarinic acetylcholine receptors. (ebi.ac.uk)
- Molecular biology of muscarinic acetylcholine receptors. (ebi.ac.uk)
- Functional analysis of muscarinic acetylcholine receptors using knockout mice. (ebi.ac.uk)
- Acetylcholinergic neurons (AchNs) in the pedunculopontine tegmental nucleus (PPN) are involved in mental development, and disruption of neuronal nicotinic acetylcholine receptors can lead to epilepsy. (hindawi.com)
- FIGURE 3 OMITTED] [FIGURE 4 OMITTED] An important role of parasympathetic cholinergic neurons and postsynaptic muscarinic acetylcholine receptors in the contraction of gastric smooth muscle has been provided in functional studies (Makhlouf and Murthy, 2006). (acronymfinder.com)
- FIGURE 5 OMITTED] [FIGURE 6 OMITTED] The present study further investigated the potential involvement of muscarinic acetylcholine receptors . (acronymfinder.com)
- About M1 Receptors M1 muscarinic acetylcholine receptors are Gq-coupled receptors known to be important for learning and memory. (acronymfinder.com)
- Myasthenia gravis is an autoimmune disorder manifested by muscle weakness caused by the loss or dysfunction of acetylcholine receptors (AChR) of skeletal muscle. (labcorp.com)
- Clinical correlations of antibodies that bind, block, or modulate human acetylcholine receptors in myasthenia gravis. (labcorp.com)
- To understand how acetylcholine brings about a variety of effects in different cells it is necessary to understand membrane receptors . (encyclopedia.com)
- In post-synaptic membranes (those of the cells on which the nerve fibres terminate) there are many different sorts of receptors and some are receptors for acetylcholine. (encyclopedia.com)
- Two major types of acetylcholine receptors exist in the membranes of cells. (encyclopedia.com)
- These terms are used because nicotine mimics the action of acetylcholine at nicotinic receptors, whereas muscarine, an alkaloid from the mushroom Amanita muscaria , mimics the action of acetylcholine at the muscarinic receptors. (encyclopedia.com)
- Muscarinic acetylcholine receptors are found in both the central nervous system and the peripheral nervous system of the heart, lungs, upper gastrointestinal tract, and sweat glands. (wikipedia.org)
- Postsynaptic defects are the most frequent cause of CMS and often result in abnormalities in nicotinic acetylcholine receptors. (wikipedia.org)
- AChR antibodies may also be positive with some thymomas, in people who are being treated with drugs such as penicillamine, with some small cell lung cancers, with autoimmune liver disease, and with Lambert-Eaton myasthenic syndrome (a condition associated with interference with the release of acetylcholine from the nerve ending). (labcorp.com)
- We offer Acetylcholine Antibodies for use in common research applications: ELISA, Immunohistochemistry, Immunohistochemistry-Frozen. (novusbio.com)
- Our Acetylcholine Antibodies can be used in a variety of model species. (novusbio.com)
- Choose from our Acetylcholine polyclonal antibodies. (novusbio.com)
- Acetylcholine also has other effects on excitability of neurons. (bionity.com)
- but only at ~ 1/3 the rate of ACh and it is resistant to BChE Pharmacological Properties of the Choline Esters 1 AChE2 CVS Acetylcholine Methacholine Carbachol Bethanechol 1 2 Muscarinic Effects GIT ++ ++ +++ +++ GUS ++ ++ +++ +++ Eye + + ++ ++ 3 Atropine +++ +++ + +++ 4 Nicotinic ++ + +++ - +++ + th ++ +++ + ± Goodman & Gilman 7 Ed. some substitutions result in resistance to hydrolysis carbachol. (scribd.com)
- Nathanson NM (1989) Regulation and development of muscarinic acetylcholine number and function. (els.net)
- they mediate many of the effects of acetylcholine in the central and peripheral nervous system and modulate a variety of physiological functions, such as airway, eye and intestinal smooth muscle contraction, heart rate and glandular secretions. (ebi.ac.uk)
- M2 muscarinic autoreceptors modulate acetylcholine release in prefrontal cortex of C57BL/6J mouse. (ebi.ac.uk)
- Acetylcholine has been shown to enhance the amplitude of synaptic potentials following long-term potentiation in many regions, including the dentate gyrus, CA1 , piriform cortex , and neocortex . (bionity.com)
- Muscle movement starts when an impulse is sent down a nerve to the nerve ending, where it stimulates the release of acetylcholine. (labtestsonline.org)
- Acetylcholine functions in both the central nervous system (CNS) and the peripheral nervous system (PNS). (wikipedia.org)
- Acetylcholine, while inducing contraction of skeletal muscles, instead induces decreased contraction in cardiac muscle fibers. (bionity.com)
- When a contractile response was achieved with extracellular Ca2+, both acetylcholine and NPS2143 reversed the H/R-induced abnormal vascular vasoconstriction, and acetylcholine reversed the calcimimetic R568-induced abnormal vascular vasoconstriction in the artery rings. (mendeley.com)
- Acetylcholine travels across a microscopic gap between the nerve ending and a muscle fiber at the "neuromuscular junction. (labtestsonline.org)
- Acetylcholine is stored in the nerve terminal, sequestered in small vesicles awaiting release. (encyclopedia.com)
- Acetylcholine is also an important transmitter at many sites in the brain at nerve-to-nerve synapses. (encyclopedia.com)
- On release, acetylcholine acts almost instantly, to cause a sequence of chemical and physical events (starting with depolarization of the motor endplate) which cause contraction of the muscle fibre. (encyclopedia.com)
- After release acetylcholine is broken down by the enzyme acetylcholinesterase . (wikipedia.org)
- You must check to make sure that it is safe for you to take acetylcholine with all of your drugs and health problems. (drugs.com)
- Acetylcholine acts as a transmitter between motor nerves and the fibres of skeletal muscle at all neuromuscular junctions . (encyclopedia.com)
- Acetylcholine pathway. (wikipedia.org)
- These are protein molecules that react specifically with acetylcholine in a reversible fashion. (encyclopedia.com)
- Substances that interfere with acetylcholine activity are called anticholinergics . (wikipedia.org)
- Acetylcholine is an ester of acetic acid and choline with chemical formula CH 3 COOCH 2 CH 2 N + (CH 3 ) 3 . (bionity.com)
- Acetylcholine is a chemical which is found in human nerves which are used to carry information regarding sense of touch, sense of smell, etc. (wikipedia.org)
- Additionally, acetylcholine reduced CaSR mRNA expression and activity when the rings were subjected to 4 h of hypoxia and 12 h of reoxygenation. (mendeley.com)
- In conclusion, this study suggests that acetylcholine ameliorates the dysfunctional vasoconstriction of the arteries after H/R, most likely by decreasing CaSR expression and activity, thereby inhibiting the increase in intracellular calcium concentration. (mendeley.com)
- Acetylcholine is the substance the nervous system uses to activate skeletal muscles, a kind of striated muscle. (wikipedia.org)
- What are some other side effects of Acetylcholine? (drugs.com)