Differential effects of dietary methyl esters of long-chain saturated and polyunsaturated fatty acids on rat liver and adipose tissue lipogenesis (original) (raw)

Four experiments were conducted to investigate what influence methyl esters of Ci«:o, Ci8:o, Ci8:i, C18:2, and Cis-.a fatty acids exert on rat liver and adipose tissue fatty acid synthesis and related enzymes when supplemented to a fat-free diet (FF). A randomized complete block design, in which rats were matched for body weight and food intake, was utilized. Rats previously adapted to a meal-eating regimen (access to food from 0900 to 1200 hours ) were fed a FF-diet for 7 days prior to the addition of the respective dietary fatty acids. In experiments 1 to 3, all esters were supplemented at a level of 3% of the daily FF-diet allotment. The apparent absorbabilities of C18:0 and Ci8:u were determined to be 40% and 35%, while values for Ci8:i, GI«^,and Ci8:3 were 88%, 87%, and 89%, respec tively. In comparison to the FF dietary treatment, polyunsaturated fatty acids (Ci8:2 and C^s) were able in three of four experiments to reduce the rate of hepatic fatty acid synthesis and the activities of hepatic fatty acid synthetase (FAS) and malic enzyme (