흰쥐에서 임신, 수유, 성장기 동안 어유의 섭취가 대뇌피질의 지방산 조성과 학습능력에 미치는 영향

Effect of the Supplementation of DHA-Rich Fish Oil during Gestation, Lactation, and Growth on the Fatty Acid Composition of Cerebral Cortex and Maze-Learning Abilities in Rats

This study was designed to investigate the effect of dietary docosahexaenoic acid (DHA) on the tissue fatty acid compositions and learning abilities of rat. Three experimental diets contained 10% (w/w) dietary lipids; corn oil based diet with perila oil (CO), corn oil based diet with fish oil (CF), and fish oil based diet (FO). Sprague Dawley female rats were fed experimental diets for approximately 2 weeks prior to mating and throughout gestation and lactation. Pups were weaned to the same diet of dams at 21 days after birth. Hepatic microsomal membrane fatty acid composition, thiobarbituric acid reactive substance (TBARS) contents and the activities of glucose 6-phosphatase (G6Pase) were measured at 7 weeks in female and 10 weeks in male rats. Cerebral cortex fatty composition and the activities of acetylcholinesterase were measured at 7 weeks. Learning abilities were tested at 8-10 weeks of age with Y water maze. The fatty acid composition of cerebral cortex were minimally, but significantly affected by that of dietary lipid than that of hepatic microsomal membrane; DHA contents were 19.2%, 20.4% and 21.9% in cerebral cortex and 8.92%, 14.2% and 19.4% in hepatic microsomal membrane of 7 week old female rats of CO, CF and FO groups. TBARS contents were the lowest in FO group at 10 weeks, and the activities of G6Pase were not affected by the experimental diets. The activity of acetylcholinesterase and learning abilities were not different among three groups. Therefore, dietary DHA supplementation to the diet with normal n-6/n-3 ratio and adequate amount of n-3 fat did not seem to promote brain functions determined in this study, nor lipid peroxidation and membrane completeness, despite significant small increase of DHA level in cerebral cortex.