从豚鼠结肠带分离出的平滑肌细胞中的两种钙通道。

Two types of Ca channels in smooth muscle cells isolated from guinea-pig taenia coli.

Yabu H, Yoshino M, Someya T, Totsuka M

Department of Physiology, Sapporo Medical College, Japan.

Adv Exp Med Biol. 1989;255:129-34. doi: 10.1007/978-1-4684-5679-0_14.

Abstract

Two types of voltage dependent Ca channels with different conductances and inactivation kinetics were identified from cell-attached patch clamp recordings. One type, with a larger conductance of 25pS, had a threshold of activation near -40mV and the mean current inactivated slowly. A second type of Ca channel, with a smaller conductance of 12pS channel, but the averaged mean current inactivated rapidly. 2) Cadmium ions inhibited the large conductance Ca channel currents, while the small conductance Ca channel currents was not blocked. 3) Large conductance Ca channel current selectively inhibited by dihydropyridine derivative, Nifedipine. Small conductance Ca channel current is abolished in dose dependent manner by pyrethroid insecticide, tetranethrine.

摘要

通过细胞贴附式膜片钳记录鉴定出两种具有不同电导和失活动力学的电压依赖性钙通道。一种类型，电导较大，为25pS，激活阈值接近-40mV，平均电流缓慢失活。第二种类型的钙通道，电导较小，为12pS通道，但平均电流快速失活。2) 镉离子抑制大电导钙通道电流，而小电导钙通道电流未被阻断。3) 大电导钙通道电流被二氢吡啶衍生物硝苯地平选择性抑制。小电导钙通道电流被拟除虫菊酯类杀虫剂四氯菊酯以剂量依赖性方式消除。