Sr2+ induce a release of divalent cation from internal Ca2+ store by nerve stimulation at frog neuromuscular junction.
The effects of Sr2+ on the transmitter release at the frog neuromuscular junction were examined electrophysiologically. The nerve trunk was stimulated by paired pulses at various time intervals after replacing extracellular Ca2+ by Sr2+, the paired-pulse facilitation at the 10 ms interval was smaller than that at 20-30 ms intervals. Administration of several intracellular Ca2+ mobilizers decreased the paired-pulse facilitation. These results suggest that the transmitter release in Sr2+ solution is caused, at least partly, by the release of divalent cations from the intracellular stores.
Tanabe
N
N
Daiichi Hoiku Junior College, Dazaifu, Fukuoka, Japan. e76141g@wisdom.cc.kyushu-u.ac.jp
Morota
A
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007700:Kinetics; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D011898:Ranidae; D013324:Strontium / Q000494:pharmacology*
D002413:Cations, Divalent; D002118:Calcium; D013324:Strontium