槐果碱的心脏电生理效应

目的研究中药单体槐果碱对心脏快、慢反应动作电位和离体心脏心电图的影响,初步探讨其抗心律失常的机制。方法应用细胞内微电极技术和Langendorff离体心脏灌流的方法,研究槐果碱对心肌细胞快、慢反应动作电位和离体心脏心电图的影响。结果槐果碱可使豚鼠心室乳头肌快反应动作电位的时程(APD50,APD90)和有效不应期(ERP)延长,0期上升速率(Vmax)降低,且呈剂量依赖性变化;可使家兔窦房结慢反应动作电位4期自动除极速率(SDVP4)、自律性兴奋频率(SEF)和动作电位幅值(APA)明显减小,此效应亦呈浓度依赖性;在豚鼠离体心电图实验中,槐果碱能对抗肾上腺素诱发的快速性心律失常。结论根据槐果碱对动物心脏电生理活动的影响,初步推测其可能通过抑制钠、钾和钙离子通道而产生抗心律失常效应。

Cardiac electrophysiological effect of sophocarpine

Objective To explore effect of sophocarpine on fast and slow response action and isolated cardiac electrocardiogram(ECG) and the anti-arrhythmia function. Methods Conventional microelectrode technique was emplogyed to record the fast and slow response action potenitals of the isolated papillary muscles of guinea pigs and sinus node tissue of rabbits,respectively.In vitro ECGs were documented from the Langendorff-perfused hearts. ResultsSophocarpine could dose-dependently prolong action potential duration(APD50 and APD90) and effective refractory period(ERP) in the fast response action potential of the guinea pigs.The maximum ascending velocity(Vmax) of 0 phase decreased.In the experiments of slow response action potential,sophocarpine inhibited effectively the spontaneous depolarization rate(SDVP4),spontaneous heart rate(SHR),and action potential amplitude(APA) in sinus node tissue of rabbit.In vitro ECGs showed that sophocarpine reversed the tachyarrhythmia induced by epinephrine. ConclusionSophocarpine may carry out its anti-arrhythmia function by inhibiting sodium,potassium and calcium channels.