Effect of nickel deficiency on fatty acid composition of total lipids and individual phospholipids in brain and erythrocytes of rats

The present investigation was designed to examine the effect of nickel deficiency on fatty acid composition of total lipids and individual phospholipids in brain and erythrocyte membranes of rats. Therefore, a study over two generations was conducted feeding a nickel-deficient diet containing 13 micrograms/kg nickel or a nickel-adequate control diet supplemented with 1 mg/kg nickel. Male 7 week old rat pups from the second offspring were studied. The concentrations of individual brain phospholipids did not differ between the nickel-deficient and the nickel-adequate group, whereas in erythrocyte membranes the concentration of phosphatidylethanolamine (PE) diacyl was reduced in consequence of nickel depletion. Moreover, nickel deficiency slightly altered fatty acid composition of total lipids and individual phospholipids both in brain and erythrocytes. The changes in fatty acids were more marked in erythrocytes than in brain, and mainly concerned phosphatidylcholine (PC). The fatty acid composition in total lipids of brain was hardly affected by nickel. In brain individual phospholipids nickel deficiency slightly, but significantly elevated the proportions of polyunsaturated fatty acids (PUFA), and in the case of PC additionally increased the levels of monounsaturated fatty acids (MUFA) at the extent of saturated fatty acids (SFA). Total lipids of erythrocytes from nickel-deprived rats had a significantly higher proportion of total MUFA than nickel-adequate rats, and a somewhat lower proportion of total (n-6) PUFA. Individual phospholipids in erythrocytes from nickel-deficient pups tended to have lower PUFA levels than nickel-adequate rats, and had additionally inconsistently altered levels of SFA and MUFA in PC and PE plasmalogen, respectively. Moreover, individual erythrocyte phospholipids from nickel-deficient rats tended to have lower 20:4/18:2 ratios than nickel-adequate rats.