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目的:探讨小窝蛋白(Cav-3)/细胞外信号调节激酶(ERK)信号通路在吗啡预处理减轻慢性心力衰竭大鼠心肌缺血再灌注损伤中的作用。方法:清洁级健康雄性成年SD大鼠，体重200~250 g，结扎冠状动脉左前降支6周制备慢性心力衰竭模型。取慢性心力衰竭和Langendorff灌注模型制备成功的大鼠心脏36个，采用随机数字表法分为4组(n n＝9)：心肌缺血再灌注组(IR组)、吗啡预处理组(MP组)、吗啡预处理+甲基-β-环糊精组(MP+MβCD组)、甲基-β-环糊精对照组(MβCD组)。采用全心停灌30 min再灌注120 min的方法建立离体心脏全心缺血再灌注损伤模型。MP组于平衡灌注15 min后灌注含1 μmol/L吗啡的K-H液进行预处理，灌注5 min后改为K-H液灌注5 min，3个循环共计30 min，处理结束后全心停灌30 min再灌注120 min。MP+MβCD组于吗啡预处理前10 min灌注含200 μmol/L甲基-β-环糊精的K-H液，其余操作同MP组。MβCD组：于全心停灌前40 min灌注含200 μmol/L甲基-β-环糊精的K-H液，其余操作同IR组。于平衡灌注15 min(Tn 0)、再灌注5 min(Tn 1)、10 min(Tn 2)时收集冠状动脉流出液，采用化学比色法检测LDH活性。再灌注120 min时，测定心肌梗死体积(IS)、缺血危险区体积(AAR)，计算IS/AAR；采用Western blot法检测心肌组织Cav-3、ERK1/2、磷酸化ERK1/2(p-ERK1/2)表达水平，计算p-ERK1/2/ERK1/2比值。n 结果:与IR组比较，MP组IS和IS/AAR降低，冠状动脉流出液LDH活性降低，心肌组织Cav-3表达上调，p-ERK1/2/ERK1/2比值升高(n P0.05)；与MP组比较，MP+MβCD组IS和IS/AAR升高，冠状动脉流出液LDH活性升高，心肌组织Cav-3表达下调，p-ERK1/2/ERK1/2比值降低(n P<0.05)。n 结论:吗啡预处理减轻慢性心力衰竭大鼠心肌缺血再灌注损伤的机制可能与激活Cav-3/ERK信号通路有关。“,”Objective:To investigate the role of Caveolin (Cav-3)/extracellular signal-regulated kinase (ERK) signaling pathway in reduction of myocardial ischemia-reperfusion (I/R) injury by morphine preconditioning in rats with chronic heart failure.Methods:Clean-grade healthy adult male Sprague-Dawley rats, weighing 200-250 g, were used in this study.Chronic heart failure was induced by ligating the left anterior descending coronary artery for 6 weeks.Thirty-six Langendorff-perfused hearts with chronic heart failure were divided into 4 groups (n n=9 each) by a random number table method: myocardial I/R group (group IR), morphine preconditioning group (group MP), morphine preconditioning plus methyl-β-cyclodextrin group (group MP+ MβCD), and methyl-β-cyclodextrin group (group MβCD). Global myocardial I/R was induced by 30 min ischemia followed by 120 min reperfusion.In group MP, after 15 min of equilibration, hearts were subjected to 3 cycles of 5 min perfusion with K-H solution containing 1 μmol/L morphine for preconditioning followed by 5 min perfusion with K-H solution, 30 min in total, and after the end of treatment, hearts were subjected to 30 min ischemia followed by 120 min reperfusion.In group MP+ MβCD, hearts were perfused with K-H solution containing 200 μmol/L methyl-β-cyclodextrin at 10 min before preconditioning with morphine, and the other treatments were similar to those previously described in group MP.In group MβCD, hearts were perfused with K-H solution containing 200 μmol/L methyl-β-cyclodextrin at 40 min before ischemia, and the other treatments were similar to those previously described in group IR.At the end of 15 min of equilibration (Tn 0) and 5 and 10 min of reperfusion (Tn 1, 2), coronary outflow was collected for determination of actate dehydrogenase (LDH) activity by chemical colorimetry.Myocardial infarct size (IS) and area at risk (AAR) were measured, and IS/AAR was calculated at the end of 120 min reperfusion.Myocardial tissues of left ventricle were taken to detect the expression of Cav-3, ERK1/2 and phosphorylated ERK1/2 (p-ERK1/2) by Western blot, and p-ERK1/2/ERK1/2 ratio was calculated.n Results:Compared with group IR, IS, IS/AAR and LDH activity in coronary outflow were significantly decreased, the expression of Cav-3 was up-regulated, and p-ERK1/2/ERK1/2 ratio was increased in group MP (n P<0.05). Compared with group MP, IS, IS/AAR and LDH activity in coronary outflow were significantly increased, the expression of Cav-3 was down-regulated, and p-ERK1/2/ERK1/2 ratio was decreased in group MP+ MβCD (n P<0.05).n Conclusions:The mechanism by which morphine preconditioning reduces I/R injury may be related to activation of Cav-3/ERK signaling pathway in rats with chronic heart failure.