【摘要】 目的:本研究主要通过细胞内微电极技术研究白藜芦醇对豚鼠左心室流出道自律组织的电生理效应。方法:选取体重250～300g豚鼠,应用玻璃微电极技术记录动作电位并观察给药前后动作电位的变化。观察指标:MPD、APA、Vmax、VDD、RPF、APD90。结果:(1)白藜芦醇可抑制左心室流出道自律细胞的电活动,白藜芦醇可显著降低左心室流出道自律细胞的APA、Vmax、VDD、RPF(P<0.01);而对MDP和APD50及APD90无明显作用(30、60μmol/L)。(2)白藜芦醇对L-Ca2+通道的影响,预先应用L-Ca2+开放剂BayK8644灌流标本可取消白藜芦醇对流出道起搏细胞的电生理效应;预先应用L-Ca2+阻断剂Verapamil灌流标本可加强白藜芦醇对流出道起博细胞的电生理效应。结论:白藜芦醇可抑制左心室流出道自律细胞的电活动,这些效应可能与其抑制钙离子内流有关,同时提示白藜芦醇与Verapamil对流出道起搏细胞有相似的抑制Ca2+通道电生理作用。更多还原

【Abstract】 AIM:To study the electrophysiological effects of resveratrol from grape and polygonum cuspidate on autorhythmicity organization in left ventricular outflow tract of guinea pig and its intracellular mechanism.METHODS:In choosing guinea pig weighing 250~300 g,the action potential,including its MDP(maximal diastolic potential),APA(amplitude of AP),Vmax(maximal rate of zero phase depolarization),VDD[velocity of diastolic(phase 4)depolarization],RPF(rate of pacemaker firing)and APD_ 50,APD_ 90(the duration of 50% and 90% repolarization of action potential),were observed and recorded by means of the intracellular microelectrode technique.RESULTS:(1)Resveratrol could reduce the electric activity of left ventricular outflow tract.Resveratrol(30、60、120 μmol/L)not only significantly decreased APA and Vmax,but also decreased VDD and RPF respectivily(P<0.01).While MDP and APD_ 50,APD_ 90 were not affected(30,60 μmol/L).(2)L-type calcium channel inhibitor Verapamil(1μmol/L)could enhance the effects of resveratrol(60 μmol/L),while the specimen were pretreated with L-type calcium channel agonist Bay K8644(0.5 μmol/L),the resveratrol-induced reduction in AP was significantly attenuated.All the results implied that resveratrol had similar effect on pacemaker cells in left ventricular outflow tract to Verapamil.CONCLUSION:Resveratrol can reduce the electric activity of left ventricular outflow tract,which might involve the Ca 2+ influx of membrane like Verapamil.更多还原