›› 2002, Vol. 45 ›› Issue (4): 453-458.

• 研究论文 • 上一篇    下一篇



  • 出版日期:2002-08-20 发布日期:2002-08-20

Inhibition effect of the deltamethrin and phoxim mixtures on the sodium channels of nerve cell

GAO Yong-Chuang1, GUO Zhen-Qun1, LIU An-Xi1, HAN Jia-Xiang2   

  • Online:2002-08-20 Published:2002-08-20

摘要: 应用膜片钳技术,以MN-9D神经细胞为材料研究了溴氰菊酯及辛硫磷混剂的增效机理。膜片钳实验表明10-5mol/L辛硫磷对Na+通道电流抑制作用很小,并随作用时间延长而逐步恢复。加药1 min Na+电流抑制率为6.99%,10 min为3.65%。10-6 mol/L溴氰菊酯1 min抑制率为20.28%,10 min为21.43%。对蜚蠊中枢神经系统传导的动作电位抑制中时为53 min;10-6mol/L溴氰菊酯与10-5 mol/L辛硫磷混剂1 min抑制率为34.15%,10 min为36.69%,动作电位抑制中时为40 min,因此混剂可增强对Na+通道电流的抑制作用。通过Na+电流数据、尾电流衰减时间常数统计分析表明溴氰菊酯的修饰作用主要发生在关闭和静止状态的Na+通道,减缓通道的打开,延长通道关闭或失活状态。

关键词: 溴氰菊酯, 辛硫磷, Na+通道, 增效混剂

Abstract: The synergetic mechanisms of deltamethrin and phoxim mixtures were studied on cell from a mesencephalic dopaminergic cell line MN-9D using the patch-clamp technique. The results showed that these mixtures were more powerful inhibitors of sodium currents than single pesticides, more rapidly reducing the action potential and blocking the nerve impulse of axon membrane. Recording of whole cell sodium currents showed that slow decaying tail currents were associated with repolarization following a depolarizing pulse in deltamethrin modified cells. The average constant of tail currents was concentration independent. Most cells showed a marked reduction in peak current with only a few showing an increase. The inhibition of sodium channels was concentration-dependent and could not recover later. We concluded that deltamethrin modified the action kinetics of sodium channels in such a way as to slow opening, prolong closure or otherwise inactivate them and that this modification occurs predominantly when the channels are in the closed or resting state. The inhibition of sodium currents will cause the reduction of action potential and loss of electrical excitability of axon membrane.

Key words: deltamethrin, phoxim, sodium channel, mixture synergy