Levels of dihomo-gamma-linolenate are depressed in heart phosphatidylcholine and phosphatidylethanolamine in the biotin-deficient chick.

Male broiler chicks were fed a purified diet with 0 or 500 micrograms/kg of added biotin for 21 days posthatch. Fatty acid composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were determined in erythrocytes and in heart mitochondria and microsomes of chicks at 12 and 21 days of age. The biotin-deficient (BD, 0 microgram biotin) chicks had lower body weights, lower feed efficiencies, and higher scores for dermatitis and twisted leg than the biotin-adequate (BA, 500 micrograms biotin) chicks. The erythrocyte arachidonate level in PC was higher in BD chicks compared to the BA controls, and the level increased with age in PC and PE in the erythrocytes. The level of dihomo-gamma-linolenate (20:3 omega 6) in PC and PE in heart mitochondria and microsomes was consistently decreased in BD chicks compared with that in BA chicks. In heart subcellular organelles, the level of arachidonate in PC increased, but the level of dihomo-gamma-linolenate in PE decreased with age. These data demonstrate that biotin deficiency results in dramatic changes in the fatty acid composition of specific phospholipids in chick erythrocytes and heart subcellular organelles.