Resveratrol reverses established pulmonary hypertension and attenuates right ventricular hypertrophy. Rats were injected with saline (Sal) or MCT and followed for 42 days. Resveratrol (R, 3 mg/kg/d) or sildenafil (S, 175 μg/kg/d) was administered via drinking water from 28–42 d post MCT injection. Key indices of pulmonary hypertension, RVSP (A) and RV/LV+S (B) are shown, demonstrating a significant regression in both parameters by resveratrol treatment. Body weights (C) were significantly lower in MCT-treated rats at the end of the study, reflecting a reduction in growth that spanned day 7 to day 21 post-injection. Echocardiographic changes included RV thickening in MCT-treated rats (D), an effect not changed by either resveratrol or sildenafil. Data are expressed as mean RVSP and RV/LV+S ± SEM (n = 8–12 rats). *P < 0.05 versus Sal; #P < 0.05 versus MCT.