Fatty acid pattern of tissue phospholipids in copper and iron deficiencies

Because copper and iron have been reported to be essential cofactors in delta 9 desaturation of fatty acids, the effects of different dietary intakes of copper and iron on tissue fatty acids were studied. Male Long-Evans rats (ten per group) were fed diets containing adequate, deficient or excess copper or iron. On day 42 of the dietary regimen, the animals were killed and tissues and blood were removed for analysis of metals and fatty acids of phospholipids. Compared with the copper-adequate rats, the copper-deficient rats showed increased 18:0 in liver and decreased 16:1 omega 7 in liver, heart and serum. There were no differences for 16:0 or 18:1 omega 9. Intake of excess copper did not cause an increase in products of delta 9 desaturation. Comparisons between iron-deficient and iron-adequate rats showed that iron deficiency increased 18:2 omega 6 in liver and serum and decreased 20:4 omega 6 in serum only. Relative percentages of 16:0, 18:0, 16:1 omega 7 and 18:1 omega 9 in liver and serum phospholipids were similar for both groups. Intake of excess iron caused a decrease in 18:2 omega 6; and 16:0 and 18:1 omega 9 were higher in the liver of the iron-excess group than the iron-deficient group. This study did not support the requirement for copper or iron in the delta 9 desaturation of fatty acids as expressed in phospholipids of liver, heart and serum.