The role of TGF-β1/ Smads signaling in ventricular remodeling after myocardial infarction in rats

Objective To investigate the role of TGF-β1 /Smads signaling in ventricular remodeling after myocardial infarction in rats treated with simvastatin.Methods Forty rats were randomly divided into four groups:Myocardial infarction group(MI,N=10) was induced by left anterior descending coronary artery ligation in rats,sham-operated rats(Sham,n=10) were used as control,simvastatin(Sim) treatment group(MI+Sim,n=10),Sim control group(Sim,n=10).The rats were cacrificed 8 weeks later.Heart weight/body weight(HW/BW),mean blood pressure,left wentricular end diastolic pressure(LVEDP),collagen content in un-infarcted area were examined.The mRNA levels of transforming growth factor(TGF) β1,Smad3,Smad7 were determined by RT-PCR.Results The level of HW/BW,LVEDP and collagen content,the mRNA expression of TGF-β1 and Smad3 inareas of myocardial infarction and un-infarction were significantly increased and the expression of Smad7 mRNA in these areas was decreased inMI group which compared with sham group and Sim group.(P0.05).Conclusions These results indicated that TGFβ1-Smads signaling was correlated to the ventricular remodeling after myocardial infarction.Smad3 mightpromote the process while Smad7 inhibit the process.Simvastatin may has a protective effect on ventricuar remodeling after myocardial infarction.