Focal differences in lipid metabolism of the young pig aorta Synthesis from [1 − 14c]acetate and [u− 14c]glucose in vitro

In the pig, focal areas of in vivo aortic Evans Blue accumulation (blue areas) have previously been found to show greater [3H]cholesterol uptake than areas showing no dye accumulation (white areas) 21,25. The present experiments were undertaken to examine lipid synthesis in these blue and white areas in vitro. Blue areas showed a significantly greater incorporation of [1 − 14C]acetate into total lipid than adjacent white areas, an increase which was demonstrable in all neutral lipid and phospholipid fractions. Additionally, blue and white areas differed in the percentage distribution of incorporated labelled acetate among the different lipid classes. In blue areas a significantly greater proportion of label appeared in phospholipid, which was attribut able to a greater percentage of label incorporated in phosphatidyl choline, and sphingomyelin. Blue and white areas showed no significant difference in the incorporation of [U− 14C]glucose into neutral lipid and phospholipid. Further, there was no difference in the percentage distribution of label among individual lipid fractions. The major proportion of [1− 14C]acetate incorporated appeared in the fatty acid moiety of glyceride lipid, while the major proportion of [U− 14C]glucose incorporated appeared in the glycerol moiety of glyceride lipid.