Immune dysfunction in rats fed a diet deficient in copper.

Rat pups maintained on copper (Cu)-adequate (6ppm), Cu-deficient (2 ppm) or Cu-depleted (0 ppm) diets from parturition were killed at 8-wk. Liver Cu and serum-ceruloplasmin levels confirmed that on the 0- and 2-ppm diets, a Cu-deficient state was induced. Although body weight was unaffected by the deficiency, the liver, heart, and thymus weights (% body weight) were altered. Hepatomegaly occurred in females fed 0-ppm Cu and males fed 2-ppm Cu. Heart weights increased in both sexes fed 0-ppm Cu. Thymus weights decreased in male rats fed 0-ppm Cu. Antibody titers and natural killer-cell cytotoxicity were markedly suppressed in the animals fed 0-ppm Cu. Male rats given 2-ppm Cu showed reduced antibody titer. Delayed-type hypersensitivity and prostaglandin E2 levels were not significantly affected. These studies suggest that certain components of the immune system are Cu dependent.