In vitro incorporation of [1- 14C]acetate and [1- 14C]palmitate into the aortic phospholipids of non–pregnant and pregnant female rabbits

Abstract

Summary Aortas from non-pregnant and 6 day pregnant rabbits were incubated with [l- 14 C]acetate and [l- 14 C]palmitate. 14 CO 2 was collected, and subsequently the amounts, radioactivities, fatty acid composition and fatty acid radioactivities of individual aortic phospholipids were determined. In aortas from both non-pregnant and pregnant rabbits phosphatidyl choline was present in highest amounts and also showed the highest degree of incorporation of [ 14 C]acetate. Pregnancy seemed to decrease the incorporation of [ 14 C]acetate into aortic phosphatidyl choline and phosphatidyl serine and to slightly increase acetate incorporation into phosphatidyl ethanolamine. The percentage of stearic acid in phosphatidyl choline was lower in aortas from pregnant rabbits than in the non-pregnant group. Among individual fatty acids of phosphatidyl choline and phosphatidyl ethanolamine, palmitic acid showed the highest specific activity and number of μμ moles of [ 14 C]acetate incorporated. Pregnancy decreased the incorporation of [ 14 C]acetate into the major fatty acids of phosphatidyl choline, and slightly increased the radioactivity in the fatty acids of phosphatidyl ethanolamine. The incorporation of [ 14 C]palmitate into all the aortic phospholipid classes was decreased by pregnancy. Oxidation of both the [ 14 C]acetate and [ 14 C]palmitate to 14 CO 2 was lower in the aortas from pregnant rabbits than in those from the non-pregnant group.