杜鹃花总黄酮对豚鼠心室肌细胞生物电的影响

目的观察杜鹃花总黄酮(total flavones of rhododen-dron,TFR)对离体豚鼠右心室乳头肌细胞生物电的影响,以探讨其抗心肌缺血的作用机制。方法采用标准玻璃微电极技术记录心肌细胞的静息电位以及动作电位。结果25、50mg·L-1的TFR可明显缩短动作电位复极50%、90%时程(APD50、APD90),但100、200、400mg·L-1却可明显延长APD50和APD90,200、400mg·L-1的TFR可明显降低0期的动作电位峰值(APA)及动作电位去极化最大速率(Vmax),400mg·L-1的TFR使静息电位减小,200mg·L-1TFR能延长心室肌细胞有效不应期(ERP)。结论低浓度的TFR可能有钙阻滞作用,高浓度的TFR可能对钾通道有一定的阻断作用,200mg·L-1TFR能延长心室肌细胞有效不应期。

Effects of total flavones of rhododendra(TFR)on bioelectricity of ventricular myocytes in guinea pig

Aim To study the effect of total flavones of Rhododendra(TFR)on bioelectricity changes of ventricular myocytes in guinea pigs. Methods Conventional microelectrode technique was used to record action potentials (AP) , resting potentials (RP) and effective refractory period (ERP). Results TFR 25,50 mg·L-1 decreased the action potential duration at 50%,90% repolarization (APD50,APD90) while TFR 100,200,400 mg·L-1 prolonged APD50 and APD90Significantlg. TFR 200,400 mg·L-1markedly decreased action potentials amplitude (APA) and velocity maximum of depolarization (Vmax). TFR 400 mg·L-1decreased resting potential. TFR 200 mg·L-1 prolonged ERP. Conclusion TFR may antagonize Ca2+ inward flow at lower concentration and block K+ inward flow at higher concentration.