不同浓度的乙醇对离体豚鼠心肌动作电位的影响

目的 观察不同浓度的乙醇对豚鼠心肌电生理特性的影响。方法 采用标准玻璃微电极细胞内记录技术，记录离体豚鼠心肌细胞的动作电位。观察12.5，25.0，50.0，100.0及200.0 mmol/L乙醇对心房肌和心室乳头肌动作电位各参数的改变。结果 12.5~100.0 mmol/L 乙醇对心室乳头肌细胞的细胞膜静息电位（RMP）、动作电位幅值（APA）、动作电位时程（APD）、AP复极至50%的时程（APD50）及AP复极至90%的时程（APD90）等参数无明显影响；而200.0 mmol/L乙醇可显著降低APA（P<0.05），50.0~200.0 mmol/L乙醇可明显延长心房肌细胞APD，APD50和APD90（P<0.05或P<0.01）。结论 乙醇对离体豚鼠心房肌、心室乳头肌电生理特性的影响有着明显差异。心房肌APD的延长可能与心房肌中分布的特殊离子通道被阻滞有关。

Effects of ethanol at different concentrations on action potential of guinea pig myocardium

AIM To observe the effects of ethanol at different concentrations on electric-physiological characteristics of isolated guinea pig myocardium. METHODS Standard microelectrode technique was used to record the action potentials (AP) of isolated guinea pig myocardium and the variations of 12.5, 25.0, 50.0, 100.0 and 200.0 mmol/L ethanol on AP parameters in atrium and papillary were analyzed. RESULTS Resting membrane potential (RMP), action potential amplitude (APA), action potential duration (APD), action potential duration of 50% repolarization (APD50) and action potential duration of 90% repolarization (APD90) in isolated papillary were not affected with 12.5-100.0 mmol/L ethanol but APA decreased with 200 mmol/L（P<0.05）. APD, APD50 and APD90 in isolated atrium were significantly prolonged with 50.0-200.0 mmol/L ethanol （P<0.05 or P<0.01） and APA was reduced with 200 mmol/L （P<0.05）. CONCLUSION Ethanol at different concentrations has significant different effect on electric-physiological characteristics of isolated guinea pig myocardium. The prolonged effect of APD on atrium may be related to the inhibition of special ion channels.