Amelioration of effects of severe dietary copper deficiency by food restriction in rats.

To test the effect of food restriction on responses to dietary copper deficiency, male weanling rats were fed two amounts of dietary copper via five dietary-intake regimens ranging from ad libitum to 70% of ad libitum intake. Copper-deficient rats exhibited characteristic signs, including depressed organ copper content, reduced activity of copper-dependent enzymes, enlarged hearts, and anemia. Food restriction attenuated the cardiac enlargement, red blood cell defects, and reduction of superoxide dismutase activity in copper-deficient rats. Mineral and enzyme assays suggested that possible mechanisms for this amelioration are the correction of copper status and/or the improvement of antioxidant status. Also, food restriction depressed serum cholesterol and enhanced cytochrome c oxidase activity in both copper-adequate and copper-deficient rats, which compensated for effects of copper deficiency. A second experiment illustrated that the mortality associated with severe copper deficiency was also inhibited by food restriction.