Dietary manipulation by perilla oil and fish oil of hepatic lipids and its influence on peroxisomal beta-oxidation and serum lipids in rat and mouse.

Rats and mice were fed a diet, prepared with soybean oil (SO), perilla oil (PO) or fish oil (FO), for 4 weeks. Compared with the groups of SO-feeding, FO-feeding increased content of eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and docosahexaenoic acid (22:6 n-3) and PO-feeding elevated the content of alpha-linolenic acid (18:3 n-3), 20:5 n-3 and 22:5 n-3 or hepatic lipids of both rats and mice. FO-feeding increased the activity of peroxisomal beta-oxidation in the livers of both rats and mice. The activities of peroxisomal beta-oxidation in rats and mice that were fed FO diet at a high fat (40% of energy) concentration corresponded to 20% and 30%, respectively, of the maximum activities induced by peroxisome proliferators (4-chlorophenoxyisobutyric acid or perfluorooctanoic acid). To a lesser extent, PO-feeding elevated this activity too. There were significant correlations between peroxisomal beta-oxidation activity and the content of either 20:5 n-3, 22:5 n-3 or 22:6 n-3 in hepatic lipids. FO-feeding decreased effectively serum level of cholesterol of both rats and mice. The reduction in serum cholesterol by feeding PO was less pronounced than that observed with FO-feeding. A high correlation was found between 22:6 n-3 content in hepatic lipids and serum concentration of cholesterol. Although FO-feeding lowered the level of circulating triacylglycerol, PO-feeding produced no change. No substantial correlation was observed between the hepatic content of n-3 fatty acid and the concentration of serum triacylglycerol.(ABSTRACT TRUNCATED AT 250 WORDS)