Abstract
Weanling rats, suckled by dams fed an essential fatty acid-deficient diet (EFA-DEF diet) during their lactatian period, were classified into five groups based on the ratios of γ-linolenic to α-linolenic acid (1/4-GLA, 4/1-GLA) and linoleic to α-linolenic acid (1/4-LA, 4/1-LA) added to the EFA-DEF diet. After five weeks, the graups shawed similar liver and brain weights. The tatal lipid cantent in the liver of rats fed only the EFA-DEF diet was higher than that of the other groups. Although no significant differences in the contents of total phospholipid, phosphatidylethanolamine and phosphatidylcholine in the liver and brain were shawn among the five groups, the fatty acid composition of liver phospholipids varied with the experimental diets to a certain extent. As to fatty acids in phosphatidylethanolamine of rat liver, a remarkable increase in the proportion of total ω-3-series acids following the 1/4-LA diet, and in ω-6-series acids following the 4/1-GLA diet were observed. Total ω-6-series acids were significantly increased to a greater extent by γ-linolenic acid than by linoleic acid in the diets of each ratio. It was shown that γ-linolenic acid was more readily converted into dihomo-γ-linolenic acid and arachidonic acid than linoleic acid, while a large amount of γ-linolenic acid in the diet caused a decrease of ω-3-series acids in phospholipids, similar to the effect of α-linolenic acid o n ω-6-series acids. The learning ability of rats tested with the water-filled rnultiple T-maze tended to improve during the experimental period, although no statistically significant differenCe was shown among the five groups.
