Effect of Carvedilol on Ventricular Remodeling and TGF-β_1 after Myocardial Infarction in Rabbits

Objective To investigate the role of transforming growth factor β1(TGF-β1) in ventricular remodeling after myocardial infarction(MI) in rabbits and effects of carvedilol on it.MethodsThe rabbits were randomly divided into three groups:the MI+carvedilol groups,the MI group and the sham operation group.The model of MI was induced by ligation of left ventricular branch.The sham operation group was made by the same procedure but not ligating.The rabbits were killed at 4 weeks after operation to examine hemodynamic parameters.The collagen volume fraction(CVF)was measured by using VG in noninfarcted region,and the protein expression of TGF-β1 was detected by immunohistochemical analysis in noninfarcted myocardium.Results Compared with the sham operation group,RVW/BW,LVW/BW,LVEDP and CVF were increased significantly(P0.05 or P0.01),and expression of TGF-β1 was enhanced in noninfarcted myocardium of MI group(P0.01).Compared with the MI group,RVW/BW,LVEDP and CVF were decreased significantly(P0.05 or P0.01),and expression of TGF-β1 was declined in the MI+ carvedilol group(P0.05).Conclusion TGF-β1 may be involved in the ventricular remodeling after myocardial infarction. Carvedilol could prevent the ventricular remodeling of noninfarction region,which may be associated with the attenuation of myocardial TGF-β1.