运动预处理对压力超负荷诱导的大鼠病理性心肌肥厚的影响

摘要

Objective: To explore the effect of exercise preconditioning (EP) on pathological cardiac hypertrophy and heart failure (HF) in pressure over-loaded experimental rats. Methods:A total of 60 SD rats at the age of 6 weeks were randomly divided into 3 groups, n=20 in each group. Sham-operation group, Transverse aortic constriction (TAC) group and EP + TAC group. The cardiac function and structure were evaluated by echocardiography, patholgical changes and HF biomarkers were examined for EP effect at 4 and 8 weeks after TAC. Results:Compared with Sham-operation group, the cardiac function and structure had obvious changes in the other 2 groups. Compared with TAC group, the ejection fraction in EP+ TAC group increased 15%, the heart weight index and left ventricular weight index decrease 15.7%and 20%respectively at 8 weeks after TAC, all P<0.05. Compared with Sham-operation group, the mRNA and protein expressions of ANP and BNP increased in TAC group at 4 and 8 weeks after TAC, increased in EP+TAC group at 8 week after TAC. Compared with TAC group, the mRNA expressions of ANP and BNP in EP+TAC group decreased 47%and 62%at 4 weeks after TAC, decreased 44%and 28.1%at 8 weeks after TAC, all P<0.05;the protein expression of ANP and BNP in EP+TAC group decreased 22.3%and 48%at 4 weeks after TAC, decreased 21.5%and 38.3%at 8 weeks after TAC, all P<0.01. Conclusion: EP may improve cardiac pathological hypertrophy in pressure over-loaded rats at the early stage, and delay the heart failure process.%目的：探究运动预处理（EP）对压力超负荷引起的大鼠病理性心肌肥厚和心力衰竭（心衰）的影响。　　方法：雄性6周龄SPF级SD大鼠60只分为Sham组、主动脉缩窄（TAC）组和运动预处理+主动脉缩窄（EP+TAC）组，每组20只。分别在TAC术后4周和8周时行超声心功能评价、病理检查以及心衰标志物检测来探讨EP的作用。　　结果：超声心动图和病理检测提示两个手术组的检测指标相比Sham组均有明显变化，而且两手术组间比较， EP+TAC组的各项指标均优于TAC组，特别是在术后8周时，左心室射血分数增加15%，心脏重量指数减少15.7%和左心室重量指数减少20%（P<0.05）,差异有统计学意义。从心衰标志物心钠肽和脑钠肽信使核糖核酸（mRNA）和蛋白表达来看，与Sham组比较，TAC组在两个时间点表达量均明显升高，EP+TAC组的变化在TAC术后4周时不明显，但在术后8周时升高明显。与TAC组相比，EP+TAC组的mRNA表达量在术后4周时分别下降47%和62%，术后8周时减少44.0%和28.1%（P<0.05）；蛋白表达量术后4周时下降42.3%和48.0%，术后8周时下降21.5%、38.3%（P<0.01），在术后8周时两手术组心衰标志物表达量差异较术后4周时减小。　　结论：EP能改善压力超负荷诱导大鼠病理性心肌肥厚，且在早期的保护作用明显，能够延缓心衰的进程，为进一步探究作用机制提供模型基础。