Postsynaptic nicotinic ACh receptor-operated Ca2+ transients with neostigmine in phrenic nerve-diaphragm muscles of mice.
The second phase of Ca2+ transients (aequorin luminescence) which was not accompanied by twitch tensions were generated by 0.3 microM neostigmine in indirectly-stimulated diaphragm muscles of mice. This phase was dependent on external [Ca2+]o, was inhibited by a low concentration of (+)-tubocurarine (+)-TC; 0.013-0.13 microM) or pancuronium (Panc; 0.034-0.14 microM), and was not inhibited by atropine (3 microM) or nitrendipine (10 microM). These results suggest that nicotinic acetylcholine receptor highly sensitive to (+)-TC may stimulate Ca2+ influx through receptor-operated Ca2+ channels.
Kimura
I
I
Department of Chemical Pharmacology, Faculty of Pharmaecutical Sciences, Toyama Medical and Pharmaecutical University, Japan.
Kondoh
T
T
Kimura
M
M
D000818:Animals; D002118:Calcium / Q000502:physiology*; D003964:Diaphragm / Q000187:drug effects / Q000294:innervation*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009388:Neostigmine / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000502:physiology*; D014403:Tubocurarine / Q000494:pharmacology
D011978:Receptors, Nicotinic; D009388:Neostigmine; D002118:Calcium; D014403:Tubocurarine