Effects of prostaglandin E₁ (PGE₁) on pulmonary hypertension and lung vascular remodeling in a rat monocrotaline model of human pulmonary hypertension

Prostaglandin E₁ (PGE₁) has been shown to be a potent pulmonary vasodilator in humans and in many animals. The effects of PGE₁ on the development of pulmonary hypertension and on pulmonary vascular remodeling were studied in a rat monocrotaline (MCT) model of human pulmonary hypertension. By 3 weeks after injection, MCT (80 mg/kg S.C.) had resulted in high values of mean pulmonary arterial pressure and of the ratio of right ventricular weight to left ventricle + septum weight (RV/LV + S). PGE₁ inhibited the development of pulmonary hypertension (300 μg/kg) and right ventricular hypertrophy (300 and 100 μg/kg) induced by MCT. Three weeks after the injection, the media walls of pulmonary arteries in lungs from rats given MCT were significantly thicker than those from lungs of control rats. PGE, (300, 100, and 30 μg/kg) resulted in significantly less of this morphologic change, in a dose-dependent manner. These results indicate that PGE₁ inhibits the development of pulmonary hypertension associated with lung vascular thickening induced by MCT. PGE₁ may be useful for the treatment of pulmonary hypertension in humans.