白藜芦醇对H9C2心肌细胞Kv2.1钾通道的影响

The effect of resveratrol on Kv2.1 potassium channels in cardiac myocytes

目的研究白藜芦醇对H9C2大鼠心肌细胞Kv2.1钾通道电流及蛋白的影响,探讨其抗心律失常的离子机制。方法实验采用H9C2大鼠心肌细胞,分为实验组(白藜芦醇干预)和对照组(未加入白藜芦醇)。全细胞膜片钳技术观察白藜芦醇对Kv2.1钾电流密度和电流特性的影响,Western blot检测白藜芦醇对Kv2.1钾通道蛋白的作用。结果白藜芦醇对Kv2.1钾电流有增强作用,呈时间依赖性和浓度依赖性,半数最大效应浓度为14.02μmol/L。白藜芦醇使Kv2.1电流密度增大(P<0.05),减少了Kv2.1钾通道的激活时间常数,加快该通道的激活。与对照组相比,实验组半失活最大电压V1/2由(-28.60±2.23)mV变为(-13.34±1.15)mV(P<0.05),通道失活曲线明显向正向移动15.26mV,而k值无明显变化(P>0.05)。同时实验组Kv2.1钾通道蛋白表达增强(P<0.05)。结论白藜芦醇能增大Kv2.1钾通道电流大小,加快该通道的激活,减慢通道电流的失活过程。

Objective To investigate the effect of resveratrol on Kv2.1potassium channels in H9C2cardiac myocytes.Methods The whole-cell patch-clamp technique was used to assess the effect of resveratrol on the electrophysiological characteristics of Kv2.1channel currents.Western blot was done to investigate the expression of Kv2.1channel protein.Results Resveratrol was shown to enhance the expression of Kv2.1channel currents in time-dependent and concentration-dependent with EC50(concentration for 50%of maximal effect)of 14.02μmol/L.Resveratrol also shortened the time course of activation and significantly delayed the duration of inactivation of Kv2.1 currents in a voltage-dependent manner.Interestingly,the half-maximum inactivation potential(V1/2)of Kv2.1currents was(-28.60±2.23)mV in control and became(-13.34±1.15)mV after application of Resveratrol.Resveratrol shifted the inactivation curve toward positive potentials by 15.26mV.Resveratrol was also shown to significantly enhance the expression of Kv2.1channel protein.Conclusion Resveratrol can effectively enhance Kv2.1currents,accelerate the duration of activation and delay the duration of inactivation of Kv2.1currents.[Chinese Journal of Cardiac Pacing and Electrophysiology,2020,34(5):484-487]