A novel and selective endothelin ETA receptor antagonistYM598 prevents the development of chronic hypoxia-induced pulmonary hypertension in rats

The preventive effects of the novel and selective endothelin ETA receptor antagonist YM598 on the development of pulmonary hypertension (PH) were investigated in chronic hypoxia-induced PH rats. Oral administration of YM598 at a dose of 1 mg/kg was started on the first day of chronic hypoxia exposure for 2 and 3 weeks to investigate the effects of this compound on hemodynamic and arterial blood gas variables, respectively. Cardiopulmonary organ weights were measured at the end of the 2-week administration period.