运动训练对心肌梗死后心室重构及MMP-2,MMP-9表达的影响

目的:观察大鼠心肌梗死(MI)后早期运动训练对左心室(LV)重构、心室功能、心肌间质胶原、基质金属蛋白酶(MMPs)的影响。方法:SD大鼠随机分为假手术组(Sham组)、MI对照组(AMI-Sed组)和MI+运动训练组(AMI-Ex组),结扎前降支建立MI模型。手术后1周Ex组进行8周跑台训练(运动强度相当于45%VO2max),术后第9周测量各组大鼠左心室重量、血液动力学参数,处死大鼠,用Masson染色检测左心室非梗死区心肌胶原容积分数(CVF),RT-PCR检测Ⅰ、Ⅲ型胶原纤维mRNA表达,Westernblot检测非梗死区心肌基质金属蛋白酶-2(MMP-2)及基质金属蛋白酶-9(MMP-9)蛋白表达。结果:与Sham组比较,AMI-Sed、AMI-Ex组左心室重量指数(LVWI)和左心室长轴径(LVLA)均显著增加(P0.05),运动训练对LVWI和LVLA无明显影响;与AMI-Ex组比较,AMI-Sed组RVWI、肺含水率显著增高,左心室压峰值(LVSP)和左心室压力变化最大值(+dp/dtmax)显著降低,左心室压力负最大值(LVEDP)显著升高(P均0.05);与AMI-Sed组比较,AMI-Ex组大鼠左心室非梗死区CVF降低,Ⅰ、Ⅲ型胶原纤维mRNA表达量均降低(P0.05),以Ⅰ型胶原纤维表达降低为著;与Sham组比较,AMI-Sed、AMI-Ex组MMP-2表达均显著升高(P0.05),MMP-9无显著变化;AMI-Ex组MMP-2蛋白表达显著低于AMI-Sed组(P0.05)。结论:AMI后早期运动训练可抑制非梗死区心肌纤维化、改善左心室重构及左心室功能,机制可能与抑制胶原纤维合成有关,MMP-2表达变化对此可能发挥一定作用。

Effects of exercises training on myocardial remodeling and MMP-2 and MMP-9 expressions in post myocardial infarction rats

Objective: To investigate the role of exercises training (ET) on left ventricular (LV) remodeling and dysfunction in post-ischemic failing rats by ligation of the left descending coronary artery. Method: Adult SD male rats were randomly assigned to three experimental groups including sham-operated group, post-MI control group (AMI-Sed) and MI+exercises group (AMI-Ex). Rats were housed under sedentary conditions and assigned to 8-week treadmill exercise protocol. Result: Comparing with AMI-Sed groups, in AMI...