Effects of dietary oils on pulmonary vascular reactivity and chronic hypoxic pulmonary hypertension in rats.

The effects of dietary oils on pulmonary vasoreactivity and chronic hypoxic pulmonary hypertension were assessed in rats fed on soybean oil (SO), pig oil (PO), soybean oil plus pig oil (SP) or a regular diet (HC) started two months before the onset of chronic normobaric hypoxia (10 +/- 0.5% O2 ventilation, 8 h per day, for 14 days). The mean pulmonary arterial pressure and pulmonary vasoreactivity to acute hypoxia were higher in the SO group than in the PO, SP and HC groups. Hypertrophy of the right ventricle in the SO group was more serious as well. Blood viscosity and hematocrit were augmented by chronic hypoxic in SO, PO, PS and HC groups, but no significant differences were found among them. The findings suggest that dietary soybean oil can potentiate hypoxic pulmonary vasoconstriction, and thereby promote the development of pulmonary hypertension and right ventricular hypertrophy.