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细胞外氯离子浓度对大鼠ClC-1通道去激活动力学特性的影响

张晓东, 臧益民, 周士胜, 臧伟进, 于晓江, 王跃民

第四军医大学生理学教研室.陕西,西安 710032；西安交通大学医学院药理学教研室.陕西,西安 710061

摘要

结果表明,降低细胞外氯离子浓度可增加快速去激活电流成分,减少慢速去激活成分;同时,慢速去激活和快速去激活电流的时间常数都显著减小,说明细胞外氯离子浓度的改变可影响通道去激活动力学参数,从而改变通道的门控过程。

关键词： ClC-1; 氯离子通道; 门控; 爪蟾卵母细胞; 动力学

Effect of extracellular chloride concentration on deactivation kinetics of rat ClC-1 chloride channel

Zhang Xiaodong, Zang Yimin, Zhou Shisheng, Zang Weijin, Yu Xiaojiang, Wang Yuemin

Department of Physiology,the Fourth Military Medical University.Xi^an 710032,Shaanxi；China

Abstract

The gating mechanism of ClC-1 chloride channel was studied in this paper by heteroexpression of rat wild type ClC-1 gene in Xenopus oocytes and by two-electrode voltage clamping technique. The deactivation gating kinetic parameters were obtained by applying two exponential fitting of the deactivating currents at various extracellular chloride concentrations. It was found that decrease in extracellular chloride concentration increased the fractional amplitude of fast deactivating component, and depressed the fractional amplitude of slow deactivating component accompanied by a decrease in fast and slow deactivating time constants. These results demonstrate that the deactivation kinetic parameters of ClC-1 are largely dependent on the extracellular chloride concentration, which induces changes in channel gating.

Key words: ClC-1;Chloride channels;Gating;Xenopus oocytes;Kinetics

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引用本文：

张晓东, 臧益民, 周士胜, 臧伟进, 于晓江, 王跃民. 细胞外氯离子浓度对大鼠ClC-1通道去激活动力学特性的影响[J]. 生理学报 2002; 54 (3): .

Zhang Xiaodong, Zang Yimin, Zhou Shisheng, Zang Weijin, Yu Xiaojiang, Wang Yuemin. Effect of extracellular chloride concentration on deactivation kinetics of rat ClC-1 chloride channel. Acta Physiol Sin 2002; 54 (3): (in Chinese with English abstract).