[Effects of beta-cypermethrin on voltage-gated potassium channels in rat hippocampal CA3 neurons].
The effects of beta-cypermethrin (consisting of alpha-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.
Fu
Zhi-Yan
ZY
College of Medicine, Nankai University, Tianjin 300071, China.
DU
Chun-Yun
CY
Yao
Yang
Y
Liu
Chao-Wei
CW
Tian
Yu-Tao
YT
He
Bing-Jun
BJ
Zhang
Tao
T
Yang
Zhuo
Z
D000818:Animals; D056654:CA3 Region, Hippocampal / Q000166:cytology* / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D007306:Insecticides / Q000633:toxicity; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects* / Q000502:physiology; D011722:Pyrethrins / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar
D007306:Insecticides; D024642:Potassium Channels, Voltage-Gated; D011722:Pyrethrins; C017160:cypermethrin