柴胡皂苷d对蟾蜍离体坐骨神经干电生理特性的影响

Effects of Saikosaponin d on Electrophysiological Properties of Isolated Sciatic Nerve Stem of Toads

目的:应用电生理方法观察不同浓度的柴胡皂苷d(saikosaponind,SSd)对蟾蜍离体坐骨神经干动作电生理特征的影响。方法:将制备好的蟾蜍离体坐骨神经干置于标准任氏液中浸泡15 min后,随机分为SSd 18、36、72μmol/L组和任氏液组,应用BL-420F生物机能实验系统引导神经干复合动作电位,测定神经干复合动作电位的阈强度、幅度、传导速度及不应期。结果:药物处理后与加药前进行比较,不同浓度(18、36、72μmol/L)SSd均可减小蟾蜍离体坐骨神经干动作电位的阈强度,增大其动作电位幅度,加快神经干的传导速度,且呈现较明显的浓度依赖性,差异有统计学意义(P<0.05或P<0.01)。在同一浓度下,随着处理时间的延长,动作电位的阈强度不断减小,幅度不断增大,神经传导速度不断增快,与作用时间呈现明显的正相关关系。此外,SSd具有小幅度缩短蟾蜍离体坐骨神经干动作电位不应期的药理作用,但差异无统计学意义(P>0.05)。结论:SSd可增强蟾蜍离体坐骨神经干的兴奋性,加速其神经动作电位的传导。

Objective:To detect the effect of different concentrations of saikosaponin d(SSd)on electrophysiological properties of isolated sciatic nerve stem of toads using electrophysiological method.Methods:After soaked in standard Ringer's solution for 15 minutes,the prepared toads′isolated sciatic nerve were randomized into SSd 18μmol/L,36μmol/L and 72μmol/L groups,and Ringer′s solution group,threshold intensity,amplitude,conduction velocity and refractory period of action potential of the isolated sciatic nerves guided with BL-420F biological function experimental system were measured respectively.Results:After comparing medicinal processing and before dosing,different concentrations of SSd(18,36 and 72μmol/L)could reduce threshold intensity of action potential of the isolated sciatic nerves,increase its amplitude,accelerate conduction velocity,which presented in a notable concentration-dependent manner,and the difference had statistical meaning((P<0.05 or(P<0.01)).Under the same concentrations,as the processing time prolonged,threshold intensity of action potential of the isolated sciatic nerves reduced gradually,while amplitude and conduction velocity increased,it showed a positive correlation with processing time.Besides,SSd can slightly shorten refractory period of the action potential of isolated sciatic nerve stem of toad,while the difference had no statistical meaning(P>0.05).Conclusion:SSd could enhance the excitability of isolated sciatic nerve trunk of toad and accelerate the conduction of nerve action potentials.