【摘要】 目的观察黄芪甙Ⅳ对豚鼠心电图(ECG)及心室肌动作电位的影响。方法分别在麻醉豚鼠和Langendoff心脏灌流模型上记录体表ECG和离体心脏ECG,采用细胞内微电极技术记录豚鼠右心室乳头肌的动作电位。结果黄芪甙Ⅳ能延长豚鼠体表ECG和离体心脏ECG的RR间期,这一效应具有剂量依赖性。黄芪甙Ⅳ还能缩短动作电位的时程(APD),但对静息电位、动作电位幅度和最大去极速度没有明显影响。结论黄芪甙Ⅳ具有负性变时作用,能缩短心肌细胞APD,其作用机制可能与慢钙通道有关。更多还原

【Abstract】 Objective To observe the effects of astragalosideⅥon electrocardiogram(ECG) and action potential of ventricular myocytes in guinea pigs.Methods ECG was recorded in vivo and ex vivo by using conventional ECG recording method from anesthetic guinea pigs and Langendoff perfusion model of hearts.Action potentials were recorded from isolated papillary muscles of right ventricles of guinea pigs by using microelectrode techniques.Results RR interval was prolonged by AstragalosideⅣin a dose-dependent manner both in vivo and ex vivo.AstragalosideⅣshortened action potential duration(APD),while had no effects on resting potential,action potential amplitude and maximal rate of depolarization.Conclusion AstragalosideⅣexerts a negative chronotropic effect on heart and shortens APD of cardiac myocytes,which may be involved with calcium channels.更多还原