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家兔急性缺血早期心室肌细胞跨膜电位的变化及迷走神经的保护作用

王云翔, 金嘉步, 王复周

第四军医大学生理教研室. 陕西, 西安

摘要

以在体家兔的心脏为对象,应用浮置微电极技术研究了急性缺血早期心室肌细胞跨膜电位的变化及迷走神经的保护作用。 冠状动脉的一个分支阻断后 1—5min,静息电位(RP)、动作电位振幅(APA)和 0相最大上升速率(dv/dt)_(max)均减小(P<0.01)。动作电位时程APD_(30)、APD_(50)和APD_(90)均缩短(P<0.01)。反映 2相平台时程的 APD_(30)和 APD_(50)缩短较总时程 APD_(90)的缩短更明显。 在自然心率的条件下,左颈迷走神经电刺激,可使急性缺血的心肌电位的变化有所恢复:RP、APA、(dv/dt)_(max)均增加,APD_(30)、APD_(50)、APD_(90)延长(P_(均)<0.01)。

关键词： 浮置玻璃微电极技术; 心肌细胞胯膜电位; 急性心肌缺血; 迷走神经刺激

Changes in transmembrane potentials of cardiac ventricular fibers during the early stage of acute cardiac ischemia and protective effects of vagal stimulation in rabbits

Wang Yunxiang, Jin Jiabu, Wang Fuzhou

Department of Physiology, Fourth military Medical College

Abstract

This study was carried out on rabbit hearts. Floating glass microelectrode was used to record the transmembrane potentials of cardiac ventricular fibers in situ. Resting potential (RP), action potential amplitude (APA) and maximum upstroke velocity of phase 0 (dv/dt)_(max) were decreased (P<0.01) 1-5 min after coronary occlusion. The duration of action potential, especially the time required for 30% and 50% of recovery (APD_(30), APD_(50)), was shortened, and the duration of the plateau was shortened even more markedly. These changes in potentials of the ventricular cells during acute ischemia were abolished by vagal stimulation, RP, APA, and (dv/dt)_(max) were increased (P<0.01). Vagal stimulation lengthened APD_(30), APD_(50) and APD_(90) under condition of natural heart rate, it was suggested that the lengthening of the APD during vagal stimulation was due to the decrease in heart rate. These results suggested that recovery of the transmembrane potentials of the ischemic ventricular cells during vagal stimulation was beneficial to impulse conduction in the ventricular muscles and to lengthening of the effective refractory period, which might play an important role in prevention of ventricular arrhythmia in early stage of acute ischemia.

Key words: Floating glass microelectrode;Myocardial transmembrane potential;Acute myocardial ischemia;Vagal stimulation

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引用本文：

王云翔, 金嘉步, 王复周. 家兔急性缺血早期心室肌细胞跨膜电位的变化及迷走神经的保护作用[J]. 生理学报 1986; 38 (3): .

Wang Yunxiang, Jin Jiabu, Wang Fuzhou. Changes in transmembrane potentials of cardiac ventricular fibers during the early stage of acute cardiac ischemia and protective effects of vagal stimulation in rabbits. Acta Physiol Sin 1986; 38 (3): (in Chinese with English abstract).