Effects of angiotensin I-converting enzyme inhibitor and angiotensin II type 1 receptor blocker on the right ventricular sarcoglycans and dystrophin after left coronary artery ligation

We examined the effects of trandolapril and candesartan on changes in the levels of sarcoglycans and dystrophin in the right ventricle of rats with the left coronary artery ligation. Hemodynamic and morphological alterations suggested the development of hypertrophy of the right ventricle and chronic heart failure by the 8th week. By the end of the 8th week, alpha- and beta-sarcoglycans and dystrophin were decreased. Increases in mu- and m-calpains in the hypertrophied right ventricle were associated with an elevation of casein-proteolytic activity in the cytosolic fraction. Oral administration of 3 mg/kg/day trandolapril or 1 mg/kg/day candesartan from the 2nd to 8th week after the left coronary artery ligation attenuated decreases in alpha-sarcoglycan and dystrophin and reduced the increased proteolytic activity. The results suggest that attenuation of decreases in sarcoglycans and dystrophin is a possible mechanism underlying trandolapril- and candesartan-mediated improvement of structural and functional alterations of the right ventricle in the coronary artery-ligated rat.