中文摘要：

目的：采用选择性κ阿片受体激动剂U50488H激活κ阿片受体,观察其对缺血再灌注大鼠心肌梗死面积以及血管紧张素Ⅱ、内皮素和NO的影响.方法：实验于2002-03/2003-05在解放军第四军医大学生理学教研室完成.选用健康雄性成年SD大鼠32只,随机分为4组（n=8）：①对照组：未结扎冠状动脉左前降支.②缺血再灌注组：结扎冠状动脉左前降支,给予心肌缺血45 min,并再灌注15 min.③U50488H组：预先给予U50488H 1.5 mg/kg,15 min后造模,方法同缺血再灌注组.④NorBNI组：在给予U50488H 10 min前先给予选择性κ阿片受体阻断剂Nor-BNI 0.5 mg/kg,余同U50488H组.观察各组大鼠心肌超微结构、心肌梗死面积以及血浆肌酸磷酸激酶、乳酸脱氢酶、血管紧张素Ⅱ、内皮素和一氧化氮等因子的水平.结果：32只大鼠进入结果分析.①心肌梗死面积：U50488H组小于缺血再灌注组和Nor-BNI组[（0.039±0.01）,（0.085±0.01）,（0.077±0.02）cm^2,P＜0.01],后两组差异不显著.②血浆中肌酸磷酸激酶和乳酸脱氢酶活性：缺血再灌注组大鼠高于对照组（P＜0.01）,U50488H组明显低于缺血再灌注组（P＜0.01）.③血管紧张素Ⅱ水平：缺血再灌注组大鼠高于对照组[（305±38）,（134±26）ng/L,P＜0.01],U50488H组明显低于缺血再灌注组[（197±23）ng/L,P＜0.01].④内皮素：缺血再灌注组大鼠高于对照组[（366±32）,（179±24）ng/L,P＜0.01],U50488H组明显低于缺血再灌注组[（242±27）ng/L,P＜0.01].⑤一氧化氮浓度：缺血再灌注组大鼠低于对照组[（21±6）,（58±9）mol/L,P＜0.01],U50488H组明显高于缺血再灌注组[（44±8）mol/L,P＜0.01].结论：U50488H可通过激活心脏κ阿片受体发挥心脏保护作用,并可以减少心肌酶的漏出,下调血管紧张素Ⅱ、内皮素水平以及上调一氧化氮水平.

英文摘要：

AIM： To observe the effects of selective κ-opioid receptor agonist U50488H on the infarction size, angiotensin Ⅱ （AT Ⅱ ）, endothelin （ET） and nitric oxide （NO） in rats with myocardial ischemic reperfusion injury by activating the κ-opioid receptor agonist with U50488H. METHODS： The experiment was conducted in the Department of Physiology, Fourth Military Medical University of Chinese PLA between March 2002 and May 2003. Thirty-two healthy male adult rats were randomly divided into four groups （n=8）： ①control group： the left anterior descending coronary artery （LADCA） of rats was not deligated.②Ischemic reperfusion group： rats were deligated of the LADCA, and received 15-minute reperfusion following myocardial isehemia （MI）.③U50488H group： rats were given 1.5 mg/kg U50488H in advance, and modeling was conducted at 15 minutes later with the same method as the ischemic reperfusion group. ④Nor- BNI group： 10 minutes before the administration of U50488H, rats were administrated with 0.5 mg/kg selective κ-opioid receptor blocking pharmacon Nor-BNI, and the rests were the same as the U50488H group. The myocardial uhrastructure, infarction size and levels of plasma creatine phosphokinase, lactic dehydrogenase （LAD）, AT Ⅱ , ET and NO were observed. RESULTS： A total of 32 rats were involved in the analysis of results. ① Infarction size： That of U50488H group was smaller than the ischemic reperfusion group and Nor-BNI group [（0.039 ±0.01）, （0.085 ±0.01.）, （0.077±0.02） cm^2,P 〈 0.01], while the differences between the latter two groups were not significant. ②The activities of creatine phosphokinase and LAD in plasma： Those in rats of the ischemic reperfusion group were higher than the control group （P 〈 0.01）, and those in the U50488H group were significantly lower than the ischemic reperfusion group （P 〈 0.01）. ③The level of AT Ⅱ ： that in the ischemic reperfusion group was higher than the control group [（305±38）, ?