Effects of total flavones of rhododendra (TFR) on bioelectricity of ventricular myocytes in guinea pig / 中国药理学通报

ABSTRACT

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.