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美加明和六烃季铵在交感神经元烟碱受体上作用位点的差异

刘卫, 郑建全, 刘振伟, 李立君, 万勤, 刘传缋

济南军区第88医院.山东,泰安 271000；军事医学科学院毒物药物研究所.北京 100850

摘要

为比较美加明(MEC)和六烃季铵(HEX)在交感神经元烟碱受体上作用位点的差异,实验用膜片钳全细胞记录技术研究了MEC和HEX对交感神经元烟碱诱发电流的抑制作用。在培养的颈上神经节细胞上,MEC和HEX拮抗烟碱作用的IC_(50)分别为0.0012和0.0095mmol/L,并且都加速烟碱受体脱敏。在-30、-70和-110mV钳制电压下,MEC和HEX抑制烟碱诱发电流的作用有电压依赖性。但在每隔3min连续给药的情况下,MEC的作用有使用依赖性而HEX没有,表明MEC和HEX在交感神经元烟碱受体上的作用位点不同。

关键词： 烟碱受体; 膜片钳; 交感神经元; 变构调节; 拮抗剂

Difference in action sites between mecamylamine and hexamethonium on nicotinic receptors of sympathetic neurons

Liu Wei, Zheng Jianquan, Liu Zhenwei, Li Lijun, Wan Qin, Liu Chuangui

88 Hospital of Jinan Military Region.Taian 271000,Shandong；China

Abstract

The IC_(50) of MEC and HEX for antagonizing the effect of 0.08 mmol/L nicotine was 0.0012 and 0.0095 mmol/L, respectively. Both MEC and HEX accelerated the desensitizatiopn of nicotinic receptors. Furthermore, by comparing their effects at holding potentials -30, -70 and -110 mV, it was indicated that their suppressing effect on the nicotine-induced currents was voltage-dependent. However, different from that of HEX, the inhibitory effect of MEC increased with administrating the mixture of MEC and nicotine at intervals of 3 min, indicating a use-dependent effect of MEC. It is concluded that the action site of MEC on nicotinic receptors of sympathetic neurons is different from that of HEX.

Key words: Nicotinic receptors;Patch clamp technique;Sympathetic neurons;Allosteric modulation;Antagonist

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引用本文：

刘卫, 郑建全, 刘振伟, 李立君, 万勤, 刘传缋. 美加明和六烃季铵在交感神经元烟碱受体上作用位点的差异[J]. 生理学报 2002; 54 (6): .

Liu Wei, Zheng Jianquan, Liu Zhenwei, Li Lijun, Wan Qin, Liu Chuangui. Difference in action sites between mecamylamine and hexamethonium on nicotinic receptors of sympathetic neurons. Acta Physiol Sin 2002; 54 (6): (in Chinese with English abstract).