葛根素对蟾蜍离体坐骨神经干电生理特性的影响

Effects of Puerarin on Electrophysiological properties of Sciatic Nerve Stem of Toad

目的:应用电生理方法观察葛根素对蟾蜍离体坐骨神经干电生理特性的影响,为探讨葛根素对外周神经系统的作用及其机制提供理论依据。方法:将制备好的神经干置于标准任氏液中浸泡20min(作为对照组)后;随机再分3个实验组,分别为葛根素25、40、50mg浸泡组,各组又分别浸泡5、10、15、20、25min。用BL-420E+生物信号分析系统测定各组各浸泡时间点神经干动作电位的阈强度、最适强度和不应期等电生理指标。结果:经不同浓度葛根素处理后,引起神经干动作电位的阈强度除25mg组和40mg组各浸泡5min后无变化外,其余各实验组的阈强度、最适强度和不应期均随浸泡时间的延长而增大或延长,与浸泡前(对照组)相比,差异极其显著(P<0.05,P<0.01)。3组浓度间比较:葛根素50mg组对神经干动作电位电生理特性的影响明显大于葛根素25mg组和40mg组(P<0.05,P<0.01)。3组神经干动作电位消失后置新鲜任氏液浸泡均可再现。结论:葛根素能降低蟾蜍坐骨神经干的兴奋性,可逆性阻滞动作电位的产生。

Objective：The electrophysiological techniques were used to detect the effect of puerarin on electrophysiological properties of sciatic nerve stem of toad,thus to provide a theoretical basis for the study of puerarin in peripheral nerve system and its mechanism of action.Methods：After the prepared toad＇s sciatic nerve was soaked in standard Ringer＇s solution for 20 min （as a control group）,we divided it into three experimental groups,puerarin 25,40,50 mg group,and each group was soaked for 5,10,15,20, 25 min respectively.The determination of electrophysiological indices of the different time point with threshold intensity,the optimal stimulus intensity and refractory period of action potential of the sciatic nerves from each group were measued respectively by BL-420 E＋biological function experimental signal analysis system.Results：After treatment with different concentrations of puerarin solution,we discovered that the threshold intensity of the nerve trunk action potential positive,wave width,the eptimun strength and refractory period increased with the increase of soaking time,except for 25 mg and 40 mg groups soaked for 5 min.The threshold intensity of the nerve trunk action potential positive,ware width,the eptimum stength and refractory.The influence of nerve action potential electrophysiological properties of puerarin 50 mg group significantly greater than puerarin 25 mg and 40 mg group（P〈0.05,P〈0.01）.Comparison among three different concentration groups,we found that the higher voncentration of puerarin liquid the greater impact on neural stem electrophysiological indicators（P〈0.05,P〈0.01）.Three groups of nerve action potential disappear after all can reappear in the new＇s soaking liquid.After soaked in the Ringer＇s solution,the action potential of three groups which has been disappearance can still be restored. Conclusion：Puerarin injection can decrease the excitability of toad＇s sciatic nerve stem,and reversibly block the generation of the action potential.