Sildenafil improves right ventricular remodelling in monocrotaline-induced rats by decreasing myocardial apoptosis and activating peroxisome proliferator-activated receptors.

Objectives To assess the effect of sildenafil on monocrotaline-induced right ventricular (RV) remodeling and investigate the possible mechanism. Methods Rats were subcutaneously injected with monocrotaline to establish an RV remodeling model and then administered sildenafil (25 mg/kg) from days 1 to 28. After 28 days of administration, the RV systolic pressure and the RV hypertrophy index (RVHI) were measured. The morphology of the right ventricle was observed by H&E staining. The ultrastructure of the right ventricle was observed using a transmission electron microscope. The myocardial apoptosis of the right ventricle was evaluated by TUNEL staining. The protein expression of apoptosis-related proteins and PPARs were examined by western blotting. Key findings The results indicated that sildenafil decreased the RV systolic pressure and RVHI, and improved the microstructure and ultrastructure of the right ventricle in monocrotaline-induced rats. In addition, sildenafil suppressed myocardial apoptosis and promoted the protein expression of PPARs of the right ventricle in monocrotaline-induced rats. Conclusion Sildenafil inhibits RV remodeling in monocrotaline-induced rats, which might be partially mediated by reducing myocardial apoptosis and activating PPARs. [ABSTRACT FROM AUTHOR]