辛伐他汀对心肌梗死后大鼠心肌间质重构的影响

目的探讨HMG-CoA还原酶抑制剂辛伐他汀对心肌梗死后大鼠心肌间质重构的影响。方法结扎大鼠冠状动脉左前降支建立心肌梗死模型,24h后存活大鼠随机分为心肌梗死组(MI组)、辛伐他汀20mg组(20mg·kg-1·d-1)和40mg组(40mg·kg-1·d-1),另单设假手术组(Sham组)。8wk后检测左、右心室重量指数,心肌组织胶原含量,Ⅰ型、Ⅲ型胶原容积分数(CVF)及Ⅰ/Ⅲ比值,同时测定Ⅰ型、Ⅲ型胶原mRNA表达。结果MI组左、右心室重量指数增加,梗死边缘区Ⅰ型、Ⅲ型胶原容积分数及Ⅰ/Ⅲ比值均增加,Ⅰ型、Ⅲ型胶原mRNA表达增加。两个Sim组的心室重量指数均降低,梗死边缘区Ⅰ型、Ⅲ型胶原容积分数及Ⅰ/Ⅲ比值下降,但仍高于Sham组,Ⅰ型、Ⅲ型胶原mRNA表达亦较MI组降低。结论辛伐他汀能减少梗死边缘区胶原沉积,改善心肌梗死后心肌间质重构。

Effect of simvastatin on interstitial remodeling in rats with myocardial infarction

Aim To assess the effect of HMG-CoA inhibitors simvastatin on collagen remodeling in rats after myocardial infarction. Methods Myocardial infarction models were induced by ligation of anterior descending coronary artery. 24 hours later the survivals were randomly divided into 3 groups: (1) MI group; (2) 20 mg Sim group(20 mg· kg-1· d-1); (3) 40 mg Sim group(40 mg· kg-1· d-1). Rats with sham ligation formed into Sham group. After 8 weeks, the ratios of LV and RV weight to body weight (RVWI, LVWI) were examined and the collagen content was detected. The type Ⅰ and type Ⅲ collagen volume fraction (CVF) and Ⅰ/Ⅲ ratio in infarcted and non-infarcted zones were examined with PSR dyeing; also the mRNA expressions of type Ⅰ and type Ⅲ collagen in non-infarcted zone (NIZ) were detected with RT-PCR.Results Comparing with Sham group,the RVWI and LVWI in MI group increased significantly. The type Ⅰ CVF and type Ⅲ CVF in NIZ and the Ⅰ/Ⅲ ratio were increased in MI group. The mRNA expressions of type Ⅰ and type Ⅲ collagen in NIZ in MI group were higher than those in Sham group. Comparing with MI group, the RVWI and LVWI in both Sim groups were decreased significantly. The type Ⅰ CVF and type Ⅲ CVF in NIZ and the Ⅰ/Ⅲ ratio were depressed in both Sim groups, and the mRNA expressions of collagens were also lower than those in MI group, but higher than those in Sham group. Conculusion Simvastatin could attenuate the development of myocardial interstitial fibrosis in non-infarction zone to improve myocardial interstitial remodeling in rats after MI.