PHOSPHOLIPID COMPOSITION AND SYNTHESIS IN MALE RABBIT AORTAS

Aortas from normal male rabbits were incubated with several C14 labelled compounds, after which the individual phospholipids were isolated by thin layer chromatography. The order of degree of incorporation of the precursors was choline-1,2-C14 > ethanolamine-1,2-C14 > glycerol-1-C14 > acetate 1-C14. Results of incubation with ethanolamine-1,2-C14 suggested that the enzyme system for transmethylation of phosphatidyl ethanolamine to phosphatidyl choline, as well as the de novo cytidine nucleotide pathway is operative in the rabbit aorta. Aortas from normal and cholesterol-fed male rabbits were also incubated simultaneously with choline-1,2-C14 and acetate-H3. Cholesterol feeding resulted in significant increases in incorporation of choline-1,2-C14 into phosphatidyl choline and lysophosphatidyl choline and acetate-H3 into phosphatidyl choline. This increased incorporation of acetate-H3 was primarily into palmitic acid. Cholesterol feeding also was found to increase the proportions of linoleic and 8, 11, 14-eicosatrienoic acids and to decrease the proportion of arachidonic acid in aortic phosphatidyl choline. © 1968.