辛伐他汀对心肌梗死后大鼠心肌Smad蛋白表达的影响

目的:研究心肌梗死(MI)大鼠心室组织中Smads3及Smads7的表达及辛伐他汀(SIM)对Smads表达的影响。方法:将36只大鼠随机分为SIM(40mg·kg-1)组、心肌梗死(MI,生理盐水)组和假手术(SHAM,生理盐水)组,前2组制作MI模型;各组给以相应药物4周后处死大鼠,采用逆转录聚合酶链反应法分析大鼠非梗死区Smad3及Smad7的mRNA表达水平,采用Western blot法检测Smad3及Smad7蛋白的表达。结果:与SHAM组比较,MI组与SIM组Smad3表达增强,Smad7表达减弱;与MI组比较,SIM组Smad3的mRNA和蛋白表达水平减弱(P<0.05),Smad7的mRNA及蛋白水平增强(P<0.05)。结论:MI后早期,Smad3表达增强、Smad7表达减弱;SIM可下调MI后Smad3及上调Smad7的表达。

Effect of Simvastatin on Smad Protein Expression in Myocardial Infarction Rats

OBJECTIVE： To investigate Smad3 and Smad7 expression in cardiac tissues in myocardial infarction （MI） rats and the effect of simvastatin （SIM） on expression of Smads. METHODS： 36 rats were randomized into SIM （40 mg·kg^-1, n= 12） group, MI group （normal saline, n=12） and SHAM group （normal saline, n=12）. Rats in first two groups were induced MI model. Rats of 3 groups were sacrificed after four weeks administration. The mRNA expressions of Smad3 and Smad7 in non-infarction regions were measured by RT-PCR. Smad3 and Smad7 protein expressions were measured by Western blotting assay. RESULTS： As compared with SHAM group, the expressions of Smad3 in MI group and SIM group were increased while the expressions of Smad7 were decreased. As compared with MI group, the mRNA expression and protein expression of Smad3 in SIM group was decreased while that of Smad7 increased （P〈0.05）. CONCLUSIONS： The levels of Smad3 are up-regulated and the levels of Smad7 are down-regulated in rats in the early stage of MI. Simvastatin could down-regulate the level of Smad3 and up-regulate the level of Smad7.