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肌苷对缺氧心肌跨膜电位和收缩强度的影响

朱平军, 李震元, 俞德章

浙江医科大学生理教研室. 浙江

摘要

本工作在正常和缺氧情况下,观察肌苷对豚鼠心室乳头肌跨膜电位和收缩强度的影响。结果表明肌苷使正常心肌细胞动作电位时间[APD_(10)、APD_(50)]延长。在缺氧心肌,肌苷使细胞静息电位增大,动作电位去极化幅度增高,零期最大去极化速度加快和动作电位时间延长。肌苷增加正常心肌收缩力,使缺氧心肌收缩的衰减显著缓和,亦即使收缩功能改善,且表现剂量-依从性。肌苷对心肌细胞跨膜电位的影响提示它很可能有抗心律失常作用,特别是在缺氧心脏。肌苷对离休乳头肌收缩的影响,证明其对心肌有直接的强心作用。

关键词： 肌苷; 缺氧心肌; 跨膜电位; 心肌收缩力

Effects of inosine on the transmembrane potential and contractility of hypoxic cardiac muscle

Chu Pingchun, Li Zhenyuan, Yu Tehchang

Department of physiology, Zhejing Medical University

Abstract

Effects of inosine on transmembrane potential and contractility were observed
in guinea pig papillary muscle. The results indicated that in normal, ventricular muscle, inosine prolonged the action potential duration [APD_(10), APD_(50)]，especially at the early phase of repolarization. In the hypoxic muscle, it caused anincrease in resting potential, action potential amplitude, maximum upstroke velocity of 0 phase depolarization and prolongation of APD. Inosine increased the contractility of normal myocardium and retarded the decline of contractility following hypoxia, which showed in a dose-dependent manner. The effects of inosine on the transmembrane potential of hypoxic cardiac muscle suggested that it might have an anti-arrhythmic action, especially in the hypoxic heart. The influence of inosine on the contractility of isolated papillary muscle indicated that it had a direct, positive inotropic action on the myocardium.

Key words: Inosine;Hypoxic cardiac muscle;Transmembrane potential;Cardiac contractile force

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引用本文：

朱平军, 李震元, 俞德章. 肌苷对缺氧心肌跨膜电位和收缩强度的影响[J]. 生理学报 1987; 39 (4): .

Chu Pingchun, Li Zhenyuan, Yu Tehchang. Effects of inosine on the transmembrane potential and contractility of hypoxic cardiac muscle. Acta Physiol Sin 1987; 39 (4): (in Chinese with English abstract).