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锌离子对急性分离的大鼠骶髓后连合核神经元GABA_A受体介导电流的抑制作用

庞志平, 王殿仕, 徐天乐, 李继硕

第四军医大学解剖学教研室, 梁銶琚脑研究中心. 西安 710032

摘要

采用制霉菌素穿孔膜片箝技术，研究了锌离子（Zn2+）对急性分离的大鼠骶髓后连合核神经元GABAA受体介导电流的作用。结果表明：（1）在箝制电压为-40mV时，GABA可通过GABAA受体介导产生内向电流；（2）此电流可被Zn2+呈非电压依赖性可逆地阻断；（3）在Zn2+存在的情况下，GABA的浓度-效应曲线平行右移。上述结果提示，Zn2+可能通过变构调控机制对GANAA介导的反应产生抑制作用。

关键词： Zn~(2+); GABA_A受体; 制霉菌素穿孔全细胞记录; 分离细胞; 骶髓后连合核

Abstract

The effects of Zn2+ on GABAA-receptor mediated responses in acutely isolated rat sacral dorsal commissural nucleus (SDCN) were studied using nystatin-perforated whole cell rechniques .The results demonstrated that (1) GABA induced inward currents through activation of GABAA~at a holding potential of-40 mV; (2) GABAA-receptor mediated responses were suppressed by Zn2+ in a reversible and voltage-independent manner; and (3) in the presence of Zn2+, the concentration-response curve of CABA-induced responses was shifted to the right in a parallel manner. The results suggest that Zn2+allosterically depresses GABAA-receptor mediated currents.

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引用本文：

庞志平, 王殿仕, 徐天乐, 李继硕. 锌离子对急性分离的大鼠骶髓后连合核神经元GABA_A受体介导电流的抑制作用[J]. 生理学报 1998; 50 (6): .

, , , . . Acta Physiol Sin 1998; 50 (6): (in Chinese with English abstract).