Influence of Dietary Lipids on the Fatty Acid Composition of Neutral Lipids and Phosphatides in Chick Liver and Bile

Diets in which the fat content was derived from either cottonseed oil, linseed oil, rapeseed oil, a high linoleic acid margarine, butter, or a commercial stock diet were fed to one-week-old chicks for 6 weeks. An additional group of chicks was fed a fat-free diet. The influence of these diets on the fatty acyl content of hepatic and biliary phospholipids and non-phosphatide lipids was determined, and where possible, a direct comparison in the fatty acid content of a liver phosphatide was made with its biliary counterpart. The results demonstrated that phosphatidylethanolamine possessed distinctly different acyl groups in bile when compared with liver, and the differences were similar with all diets. Phosphatidylcholine in bile also had a different fatty acid content than the liver phosphatide but the differences were not as consistent as for phosphatidylethanolamine. Possible explanations for the alterations of the bile compounds are discussed. In general, the fatty acid content of the diet fed was reflected in the composition of liver and bile phospholipids although the patterns were, in some cases, complex to interpret.