【摘要】 目的　研究苄基四氢巴马汀 (BTHP)的抗心律失常机理。方法　采用全细胞膜片钳技术记录心室肌细胞慢激活延迟整流钾电流 (IKs)及其尾电流(IKs ,tail)。结果　BTHP在 1～ 10 0 μmol·L- 1的范围内以浓度依赖性、电压依赖性和频率依赖性方式阻滞IKs ,tail,其IC50 为 9.3μmol·L- 1(95 %可信限 :7.8～11.8μmol·L- 1)。BTHP 30 μmol·L- 1可使IKs 及IKs,tail分别降低 (40± 6 ) %和 (39± 5 ) % (P <0 .0 1)。BTHP可以抑制IKs ,tail。该药主要使IKs ,tail的失活时间常数缩短 ,从而使IKs ,tail 失活速度增加 ,而对IKs,tail的激活动力学影响不大。结论　BTHP对IKs有明显的抑制作用。更多还原

【Abstract】 AIM To clarity the antiarrhythmic mechanisms of benzyltetrahydropalmatine (BTHP). METHODS Delayed rectifier potassium current (I Ks ) was recorded by using whole-cell patch clamp technique. RESULTS I Ks was blocked by BTHP (1-100 μmol·L -1 ) in concentration-, voltage- and frequency-dependent fashion with an IC 50 9.3 μmol·L -1 (95% confidence range: 7.8-11.8 μmol·L -1 ). BTHP 30 μmol·L -1 reduced I Ks and its tail current( I Ks,tail ) by (40±6)% and (39±5)% (P <0.01). Time constants of deactivation of I Ks,tail were reduced by BTHP, with accelerating deactivation course of I Ks,tail . CONCLUSION BTHP inhibited I Ks in isolated guinea pig ventricular myocytes.更多还原