A类钙通道参与氯化钾诱导的海马突触体Ca2+内流。

Involvement of class A calcium channels in the KCl induced Ca2+ influx in hippocampal synaptosomes.

作者信息

Malva J O, Ambrósio A F, Carvalho A P, Duarte C B, Carvalho C M

机构信息

Department of Zoology, University of Coimbra, Portugal.

出版信息

Brain Res. 1995 Oct 23;696(1-2):242-5. doi: 10.1016/0006-8993(95)00816-9.

DOI:10.1016/0006-8993(95)00816-9

PMID:8574675

Abstract

Using Ca2+ channel toxins, we determined the types of voltage-sensitive calcium channels activated by two levels of KCl depolarization in hippocampal synaptosomes. The increase in the intracellular Ca2+ concentration ([Ca2+]i) induced by 30 mM KCl was equally sensitive to either omega-agatoxin IVA (omega-Aga IVA) or to omega-conotoxin MVIIC (omega-CgTx MVIIC), and the inhibition produced by these two peptides was not additive. The present results indicate that omega-Aga IVA and omega-CgTx MVIIC do not distinguish between two different VSCC in hippocampal synaptosomes and that they both inhibit a channel with the alpha 1A subunit which is present in the rat hippocampus.

摘要

利用钙离子通道毒素，我们确定了海马突触体中由两种氯化钾去极化水平激活的电压敏感性钙通道的类型。30 mM氯化钾诱导的细胞内钙离子浓度（[Ca2+]i）升高对ω-芋螺毒素IVA（ω-Aga IVA）或ω-芋螺毒素MVIIC（ω-CgTx MVIIC）同样敏感，并且这两种肽产生的抑制作用没有相加性。目前的结果表明，ω-Aga IVA和ω-CgTx MVIIC无法区分海马突触体中的两种不同电压敏感性钙通道，并且它们都抑制大鼠海马中存在α1A亚基的通道。