INVOLVEMENT OF (N-6) ESSENTIAL FATTY-ACIDS AND PROSTAGLANDINS IN LIVER LIPID-ACCUMULATION IN JAPANESE-QUAIL

Objective-To investigate the involvement of (n-6) essential fatty acid s, such as linoleic acid [18:2(n-6)] or gamma-linolenic acid [18:3(n-6 )], and of prostaglandins on liver lipid accumulation in Japanese quai l. Design-Effects of graded amounts of aspirin, which inhibits prostag landin synthesis, on liver weight were determined in experiment 1. Exp eriment 2 was designed to clarify the effect of dietary essential fatt y acid sources and inhibition of prostaglandin synthesis on the liver fat and fatty acid profile. Animals-Female Japanese quail. Procedure-I n experiment 1, from 1 to 3 weeks of age, birds were fed ad libitum th e essential fatty acids-free or linoleic acid-adequate (2%) diets with graded amounts of aspirin (0, 0.1, 0.2, and 0.4%). In experiment 2, f rom 1 to 4 weeks of age, birds were fed the same amount of essential f atty acids-free, linoleic acid-adequate, or gamma-linolenic acid (0.4% ) diets with (0.2%) or without aspirin. Results-In experiment 1, in gr oups given the essential fatty acids-free diet, liver weight increased with an increase in dietary aspirin concentration. In experiment 2, g amma-linolenic acid completely prevented liver triacylglycerol and cho lesterol accumulation induced by the essential fatty acids-free diet. Aspirin treatment significantly lowered plasma prostaglandin F-2 alpha concentration, but did not affect liver lipid concentrations. In grou ps fed the essential fatty acids-free diets, however, aspirin treatmen t increased liver weight and liver triacylglycerol concentration by 20 and 40%, respectively. Conclusions-gamma-Linolenic acid or its metabo lites, but not linoleic acid itself, are important factors in reducing fatty liver in Japanese quail with the essential fatty acids-deficien t condition.