Effect of alpha-methyldopa on the pulmonary vascular changes induced by chronic hypoxia in rats

1. Groups of young rats were kept in a hypoxic chamber or in air as control animals for 28 days. 2. Hypoxic and control animals were treated with either alpha-methyl-3,4-dihydroxyphenylalanine (alpha-methyldopa) or distilled water. 3. alpha-Methyldopa significantly reduced the increase in pulmonary artery pressure and right ventricular hypertrophy induced by chronic hypoxia and partially prevented the histological changes in the small pulmonary vessels.