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甲磺胺心定对心肌梗塞后狗心室肌与浦氏纤维细胞动作电位的影响

高天礼, J. BRACHMANN, J. SENGES

北京大学生物学系生理教研室. 北京；西德海德堡大学心脏病学系

摘要

结扎冠脉左前降支3—5d的狗左心室外壁标本(EPI)和心内壁标本(ENDO),具有正常区(NZ)和梗塞区(IZ)。用两根微电极在两区同时记录EPI心室肌细胞(VM)和ENDOPurkinje 纤维(PF)的动作电位(AP)。 甲磺胺心定(Sotalol; 5×10~(-5)—2×10~(-4)M)对12个ENDO标本NZ与IZ PF的静息电位(RP)、动作电位振幅(APA)、O 相最大上升速度(V_(max))以及传导速度(CV)均无显著影响。在12个EPI标本上,Sotalol 除轻度延缓两区CV外,对VM的RP、APA、V_(max)也无显著影响。Sotalol显著延长NZ与IZ区VM及PF的动作电位时程(APD_(95))和有效不应期(ERP),并且延长ENDO的APD_(95)与ERP的程度超过EPI。

关键词： 甲磺胺心定; 心肌梗塞; 浦氏纤维; 心室肌细胞; 动作电位

Effects of sotalol on action potentials of canine ventricular muscle fibers and purkinje fibers in postmyocardial infarction period

Gao Tianli, Johannes Brachmann, Jochen Senges

Section of Physiology, Department of Biology, Peking Universiy. Beijing, China；Department of Cardiology, University of Heidelberg. West Germany

Abstract

Mongrel dogs were anesthetized with sodium pentobarbital. A leftside thoracotomy was performed and the left anterior descending coronary artery was ligated in two stages. After 3-5 days, the dog was reanesthetized, the chest was opened to excise the heart. A preparation consisting of roughly equal portion of normal and infarcted areas was removed. The effects of sotalol (5×10~(-5) to 2×10~(-4)M) on normal (NZ) and abnormal (IZ) myocardial tissues were analyzed. Intracellular action potentials (AP) were recorded from ventricular muscle fibers (VM) and Purkinje fibers (PF) in 12 isolated epicardial (EPI) and endocardial (ENDO) preparations respectively. Sotalol has no significant effect on RP, APA, V_(max) and conductive velocity (CV) of PF in the NZ and IZ, however, only the CV of VM in both zones were slightly lengthened. APDas and ERP of PF and VM could be prolonged markedly by sotalol Increase in APD, after sotalol was significantly greater in NZ than IZ fibers, whereas ERP was more prolonged in IZ than in NZ fibers. This means post-repolarization refractoriness selectively increased in infarcted myocardium. In another series of experiments we have found that beta-receptor blockade metoprolol could not significantly increase the APDaS and ERP of both infarcted and non-infarcted myocardium tissues, suggesting that beta-blockade sotalol also has the effect of class III antiarrhythmic drugs-prolongation of myocardium repolarization and refractoriness.

Key words: Sotalol;Myocardial infarction;Purkinje fiber;Ventricular muscle fiber;Action potential

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引用本文：

高天礼, J. BRACHMANN, J. SENGES. 甲磺胺心定对心肌梗塞后狗心室肌与浦氏纤维细胞动作电位的影响[J]. 生理学报 1986; 38 (3): .

Gao Tianli, Johannes Brachmann, Jochen Senges. Effects of sotalol on action potentials of canine ventricular muscle fibers and purkinje fibers in postmyocardial infarction period . Acta Physiol Sin 1986; 38 (3): (in Chinese with English abstract).