Dietary retinol inhibits inflammatory responses of rats treated with monocrotaline

This study was designed to test the effectiveness of dietary retinol in pro tecting the heart and lung parenchyma in a monocrotaline model for lung inj ury and pulmonary hypertension in rats. Male rats were assigned to three gr oups. Two groups were injected subcutaneously with monocrotaline (17 mg/kg body weight) and fed either the control AIN-93G diet (MC) or the control di et supplemented with retinol (17 mg retinyl palmitate/kg diet)(MR). The thi rd group was fed the control diet and injected with the vehicle only (VC). Four weeks after monocrotaline treatment, the MR group had less thickening of the alveolar septal wall, less myocardial inflammation and degeneration of the right ventricle, and less vascular inflammation in the lung compared with the MC group. The supplemented dietary retinol, however, did not prev ent development of right ventricular hypertrophy and did not affect the syn thesis and secretion of surfactant phospholipids in type II pneumocytes. Th e results indicate that dietary retinol suppresses the inflammatory respons es in the heart and lungs of rats treated with monocrotaline.