The Electrophysiological Effects of Qiliqiangxin on Cardiac Ventricular Myocytes of Rats

Qiliqiangxin, a Chinese herb, represents the affection in Ca channel function of cardiac myocytes. It is unknown whether Qiliqiangxin has an effect on Na current and K current because the pharmacological actions of this herb's compound are very complex. We investigated the rational usage of Qiliqiangxin on cardiac ventricular myocytes of rats. Ventricular myocytes were exposed acutely to 1, 10, and 50 mg/L Qiliqiangxin, and whole cell patch-clamp technique was used to study the acute effects of Qiliqiangxin on Sodium current (I (Na)), outward currents delayed rectifier outward K(+) current (I (K)), slowly activating delayed rectifier outward K(+) current (I (Ks)), transient outward K(+) current (I (to)), and inward rectifier K(+) current (I (K1)). Qiliqiangxin can decrease I (Na) by 28.53% ± 5.98%, and its IC(50) was 9.2 mg/L. 10 and 50 mg/L Qiliqiangxin decreased by 37.2% ± 6.4% and 55.9% ± 5.5% summit current density of I (to). 10 and 50 mg/L Qiliqiangxin decreased I (Ks) by 15.51% ± 4.03% and 21.6% ± 5.6%. Qiliqiangxin represented a multifaceted pharmacological profile. The effects of Qiliqiangxin on Na and K currents of ventricular myocytes were more profitable in antiarrhythmic therapy in the clinic. We concluded that the relative efficacy of Qiliqiangxin was another choice for the existing antiarrhythmic therapy.