NICKEL DEFICIENCY ALTERS LIVER LIPID-METABOLISM IN RATS

The present investigation was designed to examine the effect of nickel deficiency on lipid metabolism in liver and serum lipoproteins of rat s. Therefore, a study over two generations was conducted feeding a nic kel-deficient diet containing 13 mu g/kg nickel or a nickel-adequate d iet supplemented with 1 mg/kg nickel. Male 7-wk-old pups from the seco nd offspring were studied. Pups fed a diet poor in nickel tended to ha ve lower weight gains (P < 0.15), nickel concentrations in liver (P le ss than or equal to 0.1) and iron levels in serum (P < 0.1) than nicke l-adequate rats. They were classified as nickel-deficient on the basis of significantly lower erythrocyte counts, hemoglobin concentrations, hematocrits and nickel concentrations in kidney compared with nickel- adequate rats. Nickel deficiency caused a significant triacylglycerol accumulation in liver, with greater concentrations of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids th an nickel-adequate rats. Nickel deficiency had slight but significant effects on the fatty acid composition of liver total lipids and phosph atidylcholine and phosphatidylethanolamine. Moreover, nickel-deficient rats had significantly lower activities of the lipogenic enzymes gluc ose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malic enzyme and fatty acid synthase than nickel-adequate rats. Nickel-depl eted pups had significantly higher concentrations of triacylglycerols and phospholipids in serum VLDL, and cholesterol in serum LDL than nic kel-adequate pups. Most of these alterations in lipid metabolism are s imilar to those obtained in several iron-deficiency studies. Because n ickel deficiency also slightly compromised iron status, it is possible that at least some of the observed alterations are due to the moderat e iron deficiency.