Effect of acute hypobaric hypoxia on 32-P incorporation into phospholipids of alveolar surfactant, lung, liver and plasma of rat.

Exposure of adult rats to hypobaric hypoxia caused hypolipidemia, hypotriglyceridemia and hypophospholipidemia. Hypobaric hypoxia produced an increase in liver triglyceride and cholesterol levels and a decrease in lung triglyceride, total phospholipid and phosphatidyl choline. The proportion of phosphatidyl choline in the pulmonary surfactant fraction I phospholipids (responsible for reducing surface tension) decreased (55.2% as compared to 80.4% in control animals). Incorporation of 32-P into liver phosphatidyl ethanolamine was significantly increased, incorporation into lung phosphatidyl choline and phosphatidyl ethanolamine was increased whereas a decreased incorporation into plasma phosphatidyl choline was observed. The data suggest an enhanced lipid synthesis in liver with a probable impairment of mobilization into plasma.