脑血管平滑肌细胞K（Ca）通道对细胞内四乙铵高度敏感。

High sensitivity to internal tetraethylammonium in K(Ca) channels of cerebrovascular smooth muscle cells.

作者信息

Wang Y, Mathers D A

机构信息

Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, Canada.

出版信息

Neurosci Lett. 1991 Nov 11;132(2):222-4. doi: 10.1016/0304-3940(91)90306-e.

DOI:10.1016/0304-3940(91)90306-e

PMID:1784424

Abstract

Patch clamp methods were used to study the properties of calcium-dependent K(Ca) channels in enzyme dissociated smooth muscle cells from the cerebral arteries of adult rats. Dissociated muscle cells were maintained at 4 degrees C for up to 48 h prior to use. Inside-out membrane patches excised from these cells contained a K(Ca) channel with a conductance of 92 +/- 2.6 pS in symmetrical 140 mM potassium solutions. This channel was activated by membrane depolarization and by cytoplasmic calcium, and showed negligible permeability to sodium or cesium ions. Single channel currents were reduced by internal application of tetraethylammonium ions, with a Kd = 0.31 mM.

摘要

采用膜片钳技术研究成年大鼠脑动脉酶解离平滑肌细胞中钙依赖性钾（K(Ca)）通道的特性。解离的肌细胞在使用前于4℃保存长达48小时。从这些细胞上切下的内向外膜片在对称的140 mM钾溶液中含有一个电导为92±2.6 pS的K(Ca)通道。该通道可被膜去极化和胞质钙激活，对钠离子或铯离子的通透性可忽略不计。内向施加四乙铵离子可使单通道电流减小，解离常数（Kd）为0.31 mM。