Acetate-1-14C incorporation into polyunsaturated fatty acids of phospholipids of developing chick brain

Abstract

The incorporation of acetate-1-14C into the polyunsaturated fatty acids of glycerophosphatides of chick embryonic brain has been studied. After the injection of acetate-1-14C into the yolk sac, differences were found in the degree of labeling of the major fatty acids of the ω3 and ω6 series. Arachidonic acid (20:4ω6) showed a high degree of radioactivity while docosahexaenoic acid (22:6ω3) was poorly labeled, at a period of brain development when both fatty acids were being actively deposited. Evidence is presented to indicate that the low activity in docosahexaenoic acid is not explicable on the basis of either a low or high rate of turnover of this polyenoic acid. Similar results were obtained whether the rapid early or slower late stage of brain development was examined. It is suggested that the elongation of ω3 and ω6 series acids may be under the control of different regulatory mechanisms.

Keywords

• polyunsaturated fatty acids
• ω3 and ω6
• biosynthesis
• acetate
• developing chick brain
• arachidonic acid