NATURAL AND ACCELERATED DOCOSAHEXAENOIC ACID ACCUMULATION IN THE PRENATAL RAT-BRAIN

The quantity and distribution of docosahexaenoic acid (DHA) in major b rain phospholipids (PL) was examined in the fetal rat brain before bir th, using thin-layer and capillary column gas chromatography. A rapid increment of DHA content of about 187 mu g/g brain/day was observed be tween 17 to 20 days gestation, as opposed to 39.3 +/- 2.9 mu g/g brai n/day prior to that. Single intraamniotic injections of 5 mu L ethyl-d ocosahexaenoate (R-DHA) (12 mu M, 4.25 mg) administered to 17-day-old fetuses were used to examine the uptake of DHA into brain PL. Three da ys following injection, the amount of n-3 polyunsaturated fatty acids increased by 28% compared to ethyl-oleate (Et-Ole) injected fetuses. C ompared to the n-6 fatty acid family, the relative amount of DHA incre ased in the phosphatidylserine (PS), phosphatidylethanolamine and phos phatidylcholine (PC) lipids by 15 (P = 0.02), 13 and 14%, respectively . A major increase in the pool size of phosphatidylinositol and PS (11 0 and 50.3%, respectively), and a decrease in PC (8.2%) were observed 3 d after Et-DHA as compared to Et-Ole administration. The data sugges t that a single intraamniotic administration of Et-DHA can modulate me mbrane PL content and alter PUFA composition.