Effect of irbesartan on the expression of PPAR-γ and ventricular remodeling in rats with myocardial infarction

Objective:To study the expreesion of PPAR-γ in the left ventricular myocardium in rats with myocardial infarction,and to investiagate whether the mechanism of Irbesartan reversing the ventricular remodeling is related to PPAR-γ.Methods:Myocardial infarction models were successfully induced by ligation of anterior descending coronary artery.24 h later the survivors were randomly divided into 3 groups.① MI group;② Irbesartan group 75 mg/(kg·d);③ The rats with sham ligation formed Sham group.After 6 weeks,the expreesion of PPAR-γ,the ratio of LV weight to body weight(LVWI),cross-section area(CSA)of left ventricular myocardium were examined.The collagen volume fraction(CVF) were analyzed by PSR dyeing.Results:In MI group,compared with those in Sham group,the expreesion of PPAR-γmRNA and protein in the left ventricular myocardium decraced significantly,but the LVWI,CSA and the CVF in non-infarcted zone increased.Compared with those in MI group,in Ire group,the expreesion of PPAR-γmRNA and protein in cadiocyte incraced,while the LVWI 、CSA and the CVF in non-infarcted zone decreased.Conculusion:The expression of PPAR-γ is down-regulated in the left ventricular myocardium with myocardial infarction,Irbesartan reverses the left ventricular remodeling possibly by up-regulating and activating PPAR-γ.