Independent regulation of activation and inactivation phases in non-contractile Ca2+ transients by nicotinic receptor at the mouse neuromuscular junction. 1994

H Tsuneki, and I Kimura, and M Kimura
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.

Non-contractile Ca2+ mobilization (not accompanied by muscle contraction) occurs by the prolonged activation of nicotinic acetylcholine receptor in mouse diaphragm muscles treated with anticholinesterase. To elucidate the regulation properties of non-contractile Ca2+ mobilization by nicotinic receptor, the modes of action of competitive and depolarizing neuromuscular blockers were investigated. (+)-Tubocurarine (0.07-0.1 microM), pancuronium (0.05 microM) and alpha-bungarotoxin (0.03-0.06 microM) decreased decay time (T2, duration of inactivation phase) without changes in rise time (T1, duration of activation phase) of non-contractile Ca2+ transients. These competitive antagonists also suppressed their peak amplitude at higher concentrations than those affecting T2. Contractile Ca2+ transients were not inhibited by these antagonists at the concentrations used. Decamethonium (1 microM), a depolarizing blocker, suppressed the peak amplitude of non-contractile Ca2+ transients without affecting their duration. In contrast, succinylcholine (0.3 microM) suppressed both peak amplitude and T1 without changing T2, presumably via the receptor desensitization. Succinylcholine but not decamethonium inhibited contractile Ca2+ transients at the concentrations used. These results demonstrate that the activation and inactivation phases in non-contractile Ca2+ transients are independently regulated by nicotinic acetylcholine receptor.

UI MeSH Term Description Entries
D008297 Male Males
D008815 Mice, 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. All animals within an inbred strain trace back to a common ancestor in the twentieth generation. Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D009119 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. Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009466 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. Neuromuscular Blocker,Neuromuscular Blocking Agent,Neuromuscular Blockers,Agent, Neuromuscular Blocking,Agents, Neuromuscular Blocking,Blocker, Neuromuscular,Blockers, Neuromuscular,Blocking Agent, Neuromuscular,Blocking Agents, Neuromuscular
D009469 Neuromuscular Junction The synapse between a neuron and a muscle. Myoneural Junction,Nerve-Muscle Preparation,Junction, Myoneural,Junction, Neuromuscular,Junctions, Myoneural,Junctions, Neuromuscular,Myoneural Junctions,Nerve Muscle Preparation,Nerve-Muscle Preparations,Neuromuscular Junctions,Preparation, Nerve-Muscle,Preparations, Nerve-Muscle
D011950 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. ACh Receptor,Acetylcholine Receptor,Acetylcholine Receptors,Cholinergic Receptor,Cholinergic Receptors,Cholinoceptive Sites,Cholinoceptor,Cholinoceptors,Receptors, Acetylcholine,ACh Receptors,Receptors, ACh,Receptor, ACh,Receptor, Acetylcholine,Receptor, Cholinergic,Sites, Cholinoceptive
D011978 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. Nicotinic Acetylcholine Receptors,Nicotinic Receptors,Nicotinic Acetylcholine Receptor,Nicotinic Receptor,Acetylcholine Receptor, Nicotinic,Acetylcholine Receptors, Nicotinic,Receptor, Nicotinic,Receptor, Nicotinic Acetylcholine,Receptors, Nicotinic Acetylcholine
D002121 Calcium Channel Blockers A class of drugs that act by selective inhibition of calcium influx through cellular membranes. Calcium Antagonists, Exogenous,Calcium Blockaders, Exogenous,Calcium Channel Antagonist,Calcium Channel Blocker,Calcium Channel Blocking Drug,Calcium Inhibitors, Exogenous,Channel Blockers, Calcium,Exogenous Calcium Blockader,Exogenous Calcium Inhibitor,Calcium Channel Antagonists,Calcium Channel Blocking Drugs,Exogenous Calcium Antagonists,Exogenous Calcium Blockaders,Exogenous Calcium Inhibitors,Antagonist, Calcium Channel,Antagonists, Calcium Channel,Antagonists, Exogenous Calcium,Blockader, Exogenous Calcium,Blocker, Calcium Channel,Blockers, Calcium Channel,Calcium Blockader, Exogenous,Calcium Inhibitor, Exogenous,Channel Antagonist, Calcium,Channel Blocker, Calcium,Inhibitor, Exogenous Calcium
D003964 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. Respiratory Diaphragm,Diaphragm, Respiratory,Diaphragms,Diaphragms, Respiratory,Respiratory Diaphragms
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

Related Publications

H Tsuneki, and I Kimura, and M Kimura
November 1982, British journal of pharmacology,
H Tsuneki, and I Kimura, and M Kimura
August 2000, Pharmacological research,
H Tsuneki, and I Kimura, and M Kimura
December 1994, European journal of pharmacology,
H Tsuneki, and I Kimura, and M Kimura
January 1996, Cold Spring Harbor symposia on quantitative biology,
H Tsuneki, and I Kimura, and M Kimura
December 1993, Annals of the New York Academy of Sciences,
H Tsuneki, and I Kimura, and M Kimura
September 1980, Journal of neurobiology,
Copied contents to your clipboard!