[Effects of propranolol on pulmonary hypertension, right ventricular hypertrophy and metabolic myocardial changes due to acute hypoxemia due to high altitude].

In rats, a 3-day stay at an altitude of 3454 m (paO2 approximately 55 mm Hg) provokes a 50% increase in pulmonary pressure and a 20% increase in right ventricular weight, edema of both ventricles, particularly the right, and marked alterations in energy metabolism. Propranolol (4 mg/kg/day), administered 1 day before the transfer to high altitude and during the days of stay, prevents the increase in pulmonary pressure and in right ventricular weight and decreases myocardial edema, but has no effect on the metabolic alterations.