苦参碱对豚鼠心肌细胞钾电流的抑制作用(英文)

Inhibition of matrine on potassium currents in guinea pig ventricular myocytes

目的研究苦参碱对豚鼠心肌细胞动作电位时程和钾电流的影响,探讨其抗心律失常作用的可能机制。方法应用全细胞膜片钳技术记录心室肌细胞的动作电位时程和钾电流。结果在频率0.1Hz时,苦参碱100μmol.L-1以非频率依赖方式延长动作电位复极90%的时程达40%,在-120mV抑制内向整流钾电流(IK1)接近47%,减少快激活延迟整流钾电流的尾电流达50%,对慢激活延迟整流钾电流的尾电流无影响。结论苦参碱抗心律失常的机制可能与其抑制多种钾电流和延长动作电位时程有关。

AIM To elucidate the possible antiarrhythmic mechanism of matrine. METHODS Whole-cell patch-clamp technique was used to record ionic currents in ventricular myocytes. RESULTS In guinea pig ventricular myocytes, matrine 100 μmol· L^- 1 prolonged 90% action potential duration （APDgo） by 40% at a stimulation of 0.1 Hz in a frequency-independent manner, inhibited IK1 by 47% at the test potential of - 120 mV, reduced Ikr,tail by 50% and had no effect on Iks,tail. CONCLUSION Matrine prolonged APD through blockade of multiple potassium currents, which may relate to its antiarrhythmic efficacy.