Tanabe N, Kijima H
Department of Biology, Daiichi College of Pharmaceutical Sciences, Fukuoka, Japan.
Neurosci Lett. 1988 Sep 23;92(1):52-7. doi: 10.1016/0304-3940(88)90741-0.
A Ca2+-chelator, bis-(aminophenoxy)ethane-tetraacetic acid (BAPTA) was loaded into the presynaptic nerve terminal of frog end-plate. The BAPTA-loaded preparation showed little facilitation. However, the facilitation reappeared upon addition of an ionophore, X-537A, supporting the view that the loss of facilitation was due to the Ca2+-buffering action of BAPTA. Both hypertonic conditions and erythrosin B increased both the size of end-plate potentials and frequency of miniature end-plate potentials without any recovery of facilitation at the BAPTA-loaded end-plate. This suggested that transmitter release was increased by both conditions with little change in internal Ca2+ concentration.
一种钙离子螯合剂，双（氨基苯氧基）乙烷四乙酸（BAPTA）被注入青蛙终板的突触前神经末梢。注入BAPTA的标本几乎没有显示出易化作用。然而，加入离子载体X-537A后，易化作用再次出现，这支持了易化作用丧失是由于BAPTA的钙离子缓冲作用这一观点。高渗条件和赤藓红B都增加了终板电位的大小和微小终板电位的频率，而在注入BAPTA的终板处易化作用没有任何恢复。这表明在这两种条件下递质释放增加，而细胞内钙离子浓度变化不大。
