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高效氯氰菊酯对大鼠海马CA3区神经元电压门控钾通道的影响

付志燕, 杜春芸, 姚扬, 刘朝巍, 田裕涛, 贺秉军, 张涛, 杨卓

南开大学医学院.天津 300071；南开大学生命科学学院,生物活性材料教育部重点实验室.天津 300071

摘要

利用全细胞膜片钳技术，在急性分离的新生大鼠海马CA3区锥体细胞上研究高效氯氰菊酯的两种组分高顺氯氰菊酯和高反氯氰菊酯对瞬时外向钾电流（transient outward potassiumcurrent，I_(A)）和延迟整流钾电流（delayed rectifier potassiumcurrent，I_(K)）的影响。高顺氯氰菊酯使I_(A)增大，而高反氯氰菊酯则使I_(A)减小。高顺和高反氯氰菊酯均使I_(A)激活曲线左移，反式结构还可促进I_(A)的失活。高顺和高反氯氰菊酯均使I_(K)减小，并使其激活曲线左移，而对I_(K)的失活过程无影响，高反氯氰菊酯可使I_(K)失活后恢复过程延长。结果表明，瞬时外向钾通道和延迟整流钾通道同样是高效氯氰菊酯的作用靶点，这可能是高效氯氰菊酯对哺乳动物产生毒性作用的原因之一。

关键词： 电压门控钾电流; 膜片钳; 神经元; 氯氰菊酯

Effects of #beta#--cypermethrin on voltage-gated potassium channels in rat hippocampal CA3 neurons

Fu Zhiyan, Du Chunyun, Yao Yang, Liu Chaowei, Tian Yutao, He Bingjun, Zhang Tao, Yang Zhuo

College of Medicine,Nankai University.Tianjin 300071；China

Abstract

The effects of #beta#-cypermethrin （consisting of #alplha#-cypermethrin and #theta#-cypermethrin） on the transient outward potassium current （I_(A)） and delayed rectifier potassium current （I_(K)） in freshly dissociated hippocampal CA3 neurons of rats were studied using whole-cell patch-clamp technique. The results indicated that #alpha#-cypermethrin increased the value of I_(A) and #theta#-cypermethrin decreased the value of I_(A), though both of them shifted steady activation curve of I_(A) towards negative potential. #theta#-cypermethrin contributed to the inactivation of I_(A). The results also showed that #alpha#-cypermethrin and #theta#-cypermethrin decreased the value of I_(K), and shifted the steady state activation curve of I_(K) towards negative potential. Both #alpha#-cypermethrin and #theta#-cypermethrin had no obvious effects on the inactivation of I_(K). #theta#-cypermethrin prolonged recovery process of I_(K). These results imply that both transient outward potassium channels and delayed rectified potassium channels are the targets of #beta#-cypermethrin, which may explain the mechanism of toxical effects of #beta#-cypermethrin on mammalian neurons.

Key words: voltage-activated K~(+) current;patch-clamp technique;Neurons;cypermethrin

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引用本文：

付志燕, 杜春芸, 姚扬, 刘朝巍, 田裕涛, 贺秉军, 张涛, 杨卓. 高效氯氰菊酯对大鼠海马CA3区神经元电压门控钾通道的影响[J]. 生理学报 2007; 59 (1): 63-70.

Fu Zhiyan, Du Chunyun, Yao Yang, Liu Chaowei, Tian Yutao, He Bingjun, Zhang Tao, Yang Zhuo. Effects of #beta#--cypermethrin on voltage-gated potassium channels in rat hippocampal CA3 neurons. Acta Physiol Sin 2007; 59 (1): 63-70 (in Chinese with English abstract).