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缺血预处理和外源性左旋精氨酸减小家兔心肌梗塞范围

丁延峰, 李玉龙, 何瑞荣

(河北医科大学基础医学研究所生理室，石家庄050017)

摘要

在麻醉家兔心肌缺血一再灌注(IR)模型上，观察NO前体左旋精氨酸(L-arg)、缺血预处理Up)对血流动力学和心肌梗塞范围的影响，旨在阐明外源性L-arg对家兔IR心肌有无保护作用，并探讨L-arg-NO通路是否参与IP的心肌保护效应。所得结果如下:(1)在单纯缺血(30 min)再灌注(180 min)过程中，血压、心率和心肌耗氧量呈进行性降低，心肌梗塞范围占左心室的33.9士2.4000 (2)静注L-arg (300 mg/kg)后再进行IR时，心肌梗塞范围为20.1士2.20o，较单纯IR时明显减小((P<0. 01)，预先静注NO合成酶抑制剂硝基左旋精氨酸(L-NNA )，得以取消上述L-arg对心肌的保护作用，说明外源性L-arg对IR心肌的保护作用是通过L-arg-NO通路实现的。(3) IP时心肌梗塞范围为21.9士2. loo，较单纯IR组的显著缩小((P<0. 01)，表明IP对IR心肌有明显保护效应。L-NNA不能阻止IP的心肌保护作用，提示心脏内的L-arg-NO通路不参与IP的效应。(4)外源性L-arg得以加强IP的心肌保护效应。以上结果表明:外源性L-arg对IR心肌的保护是通过L-arg-NO通路实现的，而IP的心肌保护机制可能无该通路的参与。

关键词： 缺血一再灌注; 缺血预处理; 左旋精氨酸; 硝基左旋精氨酸; 心肌梗塞范围

ISCHEMIC PRECONDITIONING AND EXOGENOUS L-ARGININE REDUCE INFARCT SIZE IN RABBIT HEART

DING YAN-FENG, LI YU-LONG, HO SHIU-YONG

Departnent of Physiology，Institute of Basic Medicine, Hebei Medical University，Shijiazhuang 050017)

Abstract

The effects of NO donor一L-arginine (L-arg) and ischemic preconditioning (IP)on the hemodynamics and myocardial infarct size were examined in the anesthetized rabbit subjected to myocardial ischemia- repefusion to define whether exogenous L-arg could exert a beneficial effect in this pathological model，and whether the L-arg-NOpathway was involved in the cardioprotection provided by IP. The results obtained were as follows:(1)During the course of ischemia(30 min)-reperfusion(180 min)，blood pressure，heart rate and myocardial oxygen consumption decreased progressively，and the myocardial infarct size occupied 33. 9士2. 4%of the whole left ventricle: (2)The
myocardial infarct size could be reduced to 20. 1士2. 2%(P<0. 01)by pretreatment with L-arg (300 mg/kg).This myocardial protective effect of L-arg was abolished by NO synthesis inhibitor一Nitro- L- arginine (L- NNA )，thereby indicating the involv& ment of L-arg-NO pathway.(3)IP significantly reduced the infarct size to 21 .9士2. 1%(P< 0. 01)，indicating the prominent cardioprotective effect of such an intervention. Since L-NNA showed no effect on the cardioprotection afforded by IP .

Key words: ischemia-reperfusion;ischemic preconditioning;L-arginine;nitro-L-arginine;myocardial infarct size

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引用本文：

丁延峰, 李玉龙, 何瑞荣. 缺血预处理和外源性左旋精氨酸减小家兔心肌梗塞范围[J]. 生理学报 1996; 48 (6): .

DING YAN-FENG, LI YU-LONG, HO SHIU-YONG. ISCHEMIC PRECONDITIONING AND EXOGENOUS L-ARGININE REDUCE INFARCT SIZE IN RABBIT HEART. Acta Physiol Sin 1996; 48 (6): (in Chinese with English abstract).