Facilitation of acetylcholine secretion in mouse motor synapses caused by calcium release from depots upon activation of L-type calcium channels.
Pharmacological disinhibition of L-type Ca(2+) channels by two ways (with agonist S(-) BAY K 8644 and iberiotoxin, a Ca(2+)-activated BK-type K(+)-channel blocker) increases quantal content of evoked end-plate potentials, which was completely prevented by ryanodine (2 microM) blockade of ryanodine receptors. We conclude that increased quantal secretion of the transmitter induced by L-type Ca(2+) channel functioning requires activation of ryanodine receptors and calcium release from depots in motor terminals in mice.
Gaydukov
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AE
Department of Human and Animal Physiology, Biological Faculty, M. V. Lomonosov Moscow State University, Russia. gaydukov@gmail.com
Melnikova
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SN
Balezina
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OP
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D051379:Mice; D009046:Motor Neurons / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D012433:Ryanodine / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D013569:Synapses / Q000187:drug effects / Q000378:metabolism*; D014700:Verapamil / Q000494:pharmacology
D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D010455:Peptides; D019837:Ryanodine Receptor Calcium Release Channel; D012433:Ryanodine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C064719:iberiotoxin; D014700:Verapamil; D000109:Acetylcholine