Effect of Dietary Fat on Lipid Secretion and Ketone Body Production in Rat Liver

Abstract

Perfused livers from rats fed different fats were used to examine the effect of dietary fat on the rate of hepatic hpoprotein synthesis and fatty acid metabolism. Dietary fats (10% level) used were safflower oil (18:2), camellia oil (18:1) and tristearin (18:0). The results were compared with those obtained from rats fed on a low-fat diet (1% safflower oil). When no oleate substrate was infused, triglyceride secretion rates were approximately the same among the different fat groups. Infusion of the fatty acid substrate increased the secretion of triglyceride to a similar extent in 10% fat groups while the magnitude of increase was more pronounced in the low-fat group. The magnitude of increases in ketone body production due to fatty acid supply was dependent either on the amount or the type of fat; the smallest on a low-fat diet and the greatest on a camellia oil diet. Rates of secretion cholesterol and phospholipid were modified by neither the amount nor the type of fat used. It was suggested that dietary fat may alter the rate of fatty acid catabohsm without modifying lipoprotein synthesis. Safflower oil distinctly modified the fatty acid profile of triglyceride secreted. Polyunsaturated fat may exert its potent hypocholesterolemic effect through the modification of the composition of lipoprotein secreted. © 1984, Center for Academic Publications Japan. All rights reserved.