Prior exposure to copper, but not iron, decreases the severity of copper deficiency in growing rats.

The development of Cu deficiency after prior exposure for 8 days to normal and high Cu and to normal and high Fe was examined in weanling male Sprague-Dawley rats. After 28 days of Cu depletion, those with high rather than normal initial Cu stores had less elevation in heart and liver weight; higher hemoglobin and hematocrit (by 17%), Cu,Zn-superoxide dismutase activity in liver (44%), cytochrome c oxidase activity in liver (66%) and heart (19%), and Cu concentration in liver (76%) and heart (37%). In contrast, high initial stores of Fe did not alter Cu status during Cu deprivation. Thus, prior exposure to Cu, but not Fe, decreased the severity of Cu deficiency.