Effects of Prolonged Continuous Exposure to 100% Oxygen at 450 mm Hg in Vivo on Lipid Synthesis in Rat Liver and Adipose Tissue Slices

Abstract

Summary

Male rats, fed ad libitum, were exposed to 100% oxygen at 450 mm Hg for periods of time varying from 1 to 3 weeks. After exposure, blood lipid assays were performed and in vitro incorporation of acetate-2-¹⁴C into CO₂ and fatty acids by slices of liver and epididymal adipose tissue was measured. The oxygen-exposed rats gained a greater amount of weight over the exposure period than did their isocalorically, pair-fed controls. Plasma lipid values obtained from oxygen-exposed rats were higher than those obtained from the pair-fed group. Fatty acid contents in liver and adipose tissue of the oxygen-exposed rats were higher than those obtained from the pair-fed control rats. Conversion of acetate to fatty acids was found to be significantly higher in adipose tissue of O₂-exposed rats than that of nonexposed controls. A similar difference was not found in the case of slices of liver obtained from the same two groups of rats. The possibility that the oxygen-enriched environment alters the utilization of foodstuffs in a manner which more efficiently conserves energy by the storage of greater amounts of fat and/or greater synthesis of lipids is discussed.