拟除虫菊酯对神经细胞膜Na^+、Ca^(2+)离子通道的影响

Effect of pyrethroids on Na +,Ca 2+ ion channel currents in rat brain neurons

为探讨拟除虫菊酯类（Ｐｙｒｅｔｈｒｏｉｄｓ，Ｐｙｓ）对神经细胞电信号传导系统的作用机制，应用膜片箝（Ｐａｔｃｈｃｌａｍｐ）技术，研究了大鼠神经细胞在Ｐｙｓ农药氰戊菊酯（Ｆｅｎｖａｌｅｒａｔｅ，Ｆｅｎ）和四甲菊酯（Ｔｅ－ｔｒａｍｅｔｈｒｉｎ，Ｔｅｔ）作用下，Ｎａ＋、Ｃａ２＋电流的变化。实验结果表明：Ｆｅｎ和Ｔｅｔ对Ｎａ＋通道的毒作用特点为：低剂量激活、高剂量抑制；对Ｃａ２＋通道的影响亦表现为低剂量激活、高剂量抑制，但激活作用较弱而抑制作用明显。此外，Ｐｙｓ可引起兴奋性突触后电位（ＥＰＳＰ）频率的增高。

Using whole cell patch clamp technique,the effects of pyrethroids(Pys) on Na +,Ca 2+ channel currents in rat brain neurons were studied.The results showed activation of Na + current at low dose and inhibition at high dose of fenvalerate(Fen) and tetramethrin(Tet).The same effects of Fen amd Tet on Ca 2+ currents were seen,however,the effect of inhibition was stronger than that of activation.The frequency of excitatory postsynaptic potential(EPSP) was also increased in rat brain neurons exposed to Pys.