The Incorporation of Intracranially Injected Glycerol IntoBrain Glycerides of Young Rats Born to Normal andAlcohol-Fed Mothers

Growth alters the ability of rat brain to incorporate [2-3H]glycerol into glycerides; indeed, 12 min after the intracranial administration of the precursor, diglyceride becomes more radioactive in newborn than in 19-day-old brain, the reverse being true for total glycerophospholipid and triglyceride. The ratio between the labeling of phospholipid and that of neutral lipid in the experimental conditions described in this paper is proposed as a marker of brain maturity. The distribution of labeling among phospholipid c1asses also varies with age, and the increase of labeling in total phospholipid occurring with increasing age is almost entirely due to phosphatidylethanolamine and phosphatidy1choline. The metabolism of myelin lipids might be responsible for these age-dependent variations. The administration of ethanol to dams during pregnancy and lactation alters the distribution of the label among neutral glycerolipid and total glycerophospholipid in an age-dependent manner. The labeling distribution among phospholipid classes is also affected.