[A model of isobaric hypoxic pulmonary hypertension in rats]

Male Wistar rats were kept in isobaric hypoxic chamber (O2 = 10%) with intermittent hypoxia for 1, 2, 4 weeks (6 hrs/day, 6 days/wk). The pulmonary arterial blood pressures increased significantly after 1 week of hypoxia, reached the maximum at 2 weeks of hypoxia and thereafter plateaued in 4 weeks of hypoxia. The elevated Pap were paralleled by increase in the right ventricular blood pressure. The prolonged exposure to hypoxia also led to the right ventricular hypertrophy, which were presented in the increase in both the weight ratio of right ventricle to the left ventricle plus septum and to the body weight. There were no significant hemodynamic changes in the pulmonary circulation by the 24 hours hypoxia. The result suggested that the intermittent hypoxia can lead to the pulmonary hypertension in the model.