脱氧鬼臼毒素对美洲大蠊背侧不成对中间神经元电压依赖性钾电流的影响

摘要

目的:探讨脱氧鬼臼毒素(DOP)对美洲大蠊背侧不成对中间神经元(DUM)电压依赖性钾电流IK的影响.方法:采用全细胞膜片钳技术研究脱氧鬼臼毒素对美洲大蠊背侧不成对中间神经元电压依赖性钾电流的电流幅度,电流-电压关系以及激活曲线的影响.结果:DOP能够抑制电压依赖性钾通道电流的幅度,而且此抑制作用具有浓度依赖性(5、10、20、40 μmol/L).DOP抑制IK的半数抑制浓度(IC50)值为18.064 μmol/L.20 μmol/L DOP能使IK的电流-电压关系曲线下移,并能使IK的激活曲线向去极化方向移动.结论:DOP对美洲大蠊背侧不成对中间神经元(DUM)电压依赖性钾电流具有抑制作用,这可能是其杀虫作用的机制之一.%Objective: To investigate the effects of deoxypodophyllotoxin (DOP) on voltage-gated potassium current Ikin Periplaneta Americana Dorsal Unpaired Median (DUM) Neurons. Methods: Ik was obtained in DUM neurons by the whole-cell patch clamp technique,and the effects of deoxypodophyllotoxin on Ik were observed. Results: Deoxypodophyllotoxin at the concentrations of 5,10,20, 40μmol/L inhibited Ik in DUM neurons cells significantly, with the IC50 value of 18.064 μmol/L.Current-voltage relationship curve decreased obviously after adding 20 μmol/L DOP, and activation curve of Ik shifted toward a depolarizing direction. Conclusion: Deoxypodophyllotoxin has inhibitory effects on Ik in Periplaneta Americana Dorsal Unpaired Median Neurons, which may be one mechanism of its insecticidal effect.