Dietary fatty acid composition in pregnancy alters neurite membrane fatty acids and dopamine in newborn rat brain

The importance of maternal dietary fatty acids on arachidonic acid [AA; 20: 4(n-6)] and docosahexaenoic acid [DHA; 22:6(n-3)] in fetal brain nerve grow th cone membranes and monoaminergic neurotransmitters was investigated. Rat s were fed purified diets containing 20 g/100 g safflower oil with 74.3% 18 :2(n-6), 0.2% 18:3(n-3), soybean oil with 55.4% 18:2(n-6), 7.7% 18:3(n-3) o r high fish oil with 24.6% 22:6(n-3) through gestation. Tissue for rats wit hin a litter were pooled at birth, brain growth cone membranes prepared and phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylethanolamin e (PE) and phosphatidylinositol (PI) fatty acids quantified by gas-liquid c hromatography. Dopamine, serotonin, and the metabolites 3,4-dihydroxyphenyl acetic acid and homovanillic acid, and 5-hydroxyindolacetic acid were quant ified by HPLC. Growth cone membranes from offspring of rats fed safflower o il had significantly lower, and offspring of rats fed high 22:6(n-3) fish o il had significantly higher 22:6(n-3) in PE, PS and PI than the soybean oil group. The growth cone membrane PC, PE and PS 20:4(n-6) was significantly lower in the fish oil than in the soybean or safflower oil groups. Serotoni n concentration was significantly higher in brain of offspring in the saffl ower oil compared with the soybean oil group. The newborn brain dopamine wa s inversely related to PE DHA and PS DHA (P < 0.001), but positively relate d to PC AA (P < 0.05). These studies show that maternal dietary fatty acids may alter fetal brain growth cone (n-6) and (n-3) fatty acids, and neurotr ansmitters involved in neurite extension, target finding and synaptogenesis . The functional importance, however, is not known at this time.