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[Cardioprotection by the inhibitory effect of nitric oxide.] [Article in Chinese]

YUE Zhi-Jie, YU Zhi-Bin^*

Department of Aerospace Physiology, the Fourth Military Medical University, Xi’an 710032, China

Abstract

Endothelial and neuronal nitric oxide synthases (eNOS and nNOS) are constitutively expressed in cardiomyocytes under the physiological condition, while inducible nitric oxide synthase (iNOS) is only expressed in cell stress. Nitric oxide (NO) derived from the constitutive isoforms of eNOS and nNOS plays four kinds of inhibitory effects on the myocardium: reducing the contractile frequency of cardiomyocyte, slightly attenuating cardiac contractility, accelerating relaxation and increasing distensibility of cardiomyocyte, and slightly inhibiting mitochondrial respiration and improving the efficiency of myocardial oxygen consumption. In conditions of enhanced cardiac reserve and cardiac hypertrophy, NO derived from eNOS, which forms a complex with a certain kind of receptor on the sarcolemma, modulates receptor-mediated signaling and generates an “accentuated antagonism” by moderate inhibition of cardiac contractility. NO derived from the complex of nNOS-ryanodine receptor (RyR) stabilizes RyR calcium release and increases the efficiency of Ca2+ cycling in sarcoplasmic reticulum by the inhibitory effects. However, besides the above-mentioned inhibitions of NO derived from eNOS and nNOS, NO derived from iNOS generally prevents mitochondrial permeability transition pore opening by inhibiting mitochondrial respiration under the conditions of the myocardial ischemia-reperfusion injury and heart failure. Therefore, both in the physiological condition and in the pathological condition, NO exhibits a moderate inhibition in cardiac function, and eventually produces cardioprotection.

Key words: Nitric oxide; cardioprotection; inhibition

Received: 2010-12-18　　Accepted: 2011-04-01

Corresponding author: 余志斌　　E-mail: yuzhib@fmmu.edu.cn

Citing This Article：

YUE Zhi-Jie, YU Zhi-Bin. [Cardioprotection by the inhibitory effect of nitric oxide.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (3): 191-197 (in Chinese with English abstract).