葛根素对大鼠心肌细胞离子通道的影响

目的: 探讨葛根素对大鼠心肌细胞离子通道的影响及其抗心律失常的电生理学机制. 方法: 采用Langendoff胶原酶灌注加浸泡法分离大鼠心室肌细胞,据不同细胞外灌流液将实验分5组:对照组;葛根素1.2, 2.4, 4.8和9.6 mmol/L组. 分别用膜片钳全细胞记录各组内向整流钾通道(Ik1)、瞬时外向钾通道(Ito)的电流. 结果: 在500 ms去极化的实验条件下,葛根素使不同去极化水平时的Ik1瞬间电流及稳态电流均明显下降. 随着药物剂量的增加,这种抑制作用也增强. 结论: 葛根素对大鼠心肌细胞离子通道的作用主要是抑制Ik1,且抑制呈浓度依赖性.

Puerarin inhibits ionic channel current Ik1 in rat cardiac myocytes

AIM: To explore the effect of puerarin on the inhibition of ionic channel current I_ k1 in rat cardiac myocytes and the related mechanism of puerarin. METHODS: Ionic channel currents (I_ k1 , I_ to ) of isolated adult rat ventricular myocytes were investigated by using whole-cell path-clamp technique. Isolated adult rat ventricular myocytes were randomly divided into 5 groups: control group, the group of 1.2 mmol/L puerarin, the group of 2.4 mmol/L puerarin, the group of 4.8 mmol/L puerarin and the group of 9.6 mmol/L puerarin. RESULTS: Puerarin decreased I_ k1 instantaneou current and steady-state current elicited by 500 ms duration of pulses depolarized to different membrane potential in a dose-dependent manner. CONCLUSION: Puerarin blocks I_ k1 of ionic channel in rat cardiac myocytes in a dose- dependent manner.