吗啡后处理对大鼠心肌缺血再灌注损伤的保护作用

目的探讨吗啡后处理对在体大鼠心肌缺血／再灌注损伤的保护作用。方法32只健康雄性SD大鼠随机分配至4个组（n=8）。假手术组（Sham组）：冠脉左前降支只套线，不结扎；缺血再灌注组（I／R组）：再灌注前5min给盐水1ml／kg；吗啡后处理组（MOR组）：再灌注前5min给予吗啡0．3mg／kg；缺血预处理组（IPC组）：先缺血5min再开放5min，反复3次，再进行冠状结扎。建立大鼠心肌缺血30min，再灌注120min动物模型，以血流动力学、心肌酶学、心肌梗死面积、心肌形态学为指标探讨吗啡后处理对再灌注心肌的作用。结果MOR组与IPC组可以降低缺血再灌注损伤引起的心肌酶学增高、显著降低心肌梗死面积（与I／R组比较，P〈0．05）。光学显微镜下I／R组呈现典型的心肌结构病理改变，MOR组和IPC组病理损伤程度较I／R组减轻。结论吗啡后处理可以减轻在体大鼠心肌缺血再灌注损伤，其心肌保护效果与缺血预处理相似。

The protective effects on rat myocardial ischemia and reperfusion injury by post-treatment with morphine

Objective To determine the protective effects of reducing myocardial ischemia and reperfusion injury （MI/R） by morphine adimistered post injury in rats. Methods Thirty-two male Sprague-Dawley（SD） rats were used for in vivo model of ischemia/reperfusion injury. Anesthetized rats were randomly assigned to the following four groups. Sham group in which the chest was opened without ligating the left coronary artery; Ischemia/reperfusion （I/R） group in which the saline was applied 5 min before reperfusion; Morphine （MOR） group in which 0.3 mg/kg morphine was given intravenously 5 min before reperfusion ; Ischemic preconditioning （IPC） group in which 5 rain ischemia and 5 min reperfusion for three cycles were applied before the long time ischemia procedure was administered. The area of infarction in myocardium was determined by tissue staining with Evan＇s blue and TTC. The contents of AST, CK-MB and LDH in the serum taken 120 min after reperfusion were measured to determine the severity of the cardiac infarction. Results Compared with I/R group, the size of infarction and the concentrations of CK-MB, AST and LDH are significantly decreased （P 〈 0.05 ） in MOR and IPC groups.