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  

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

作　　者：刘卫[1] 郑建全[2] 刘振伟[2] 李立君[2] 万勤[2] 刘传缋[2] 

机构地区：[1]济南军区第88医院,泰安271000 [2]军事医学科学院毒物药物研究所,北京100850

出　　处：《生理学报》2002年第6期497-500,共4页Acta Physiologica Sinica

基　　金：ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina (No 39770 85 0 )

摘　　要：为比较美加明 (mecamylamine,MEC)和六烃季铵 (hexamethonium ,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IC50 分别为 0 0 0 12和 0 0 0 95mmol/L ,并且都加速烟碱受体脱敏。在 - 3 0、 - 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 。To compare the difference in action sites between mecamylamine (MEC) and hexamethonium (HEX) on nicotinic receptors of sympathetic neurons, we investigated the effects of MEC and HEX on the nicotine-induced currents in cultured superior cervical ganglion neurons by whole-cell patch clamp technique. 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 desensitization 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.

关 键 词：美加明 六烃季铵 交感神经元 烟碱受体 作用位点 差异 变构调节 拮抗剂 

分 类 号：R967[医药卫生—药理学]