Changes in tissue growth, concentrations of copper, iron, cytochrome oxidase and superoxide dismutase subsequent to dietary or genetic copper deficiency in mice
Journal of Nutrition 113(10): 2048-2058
Experiments were conducted in suckling mice to investigate copper-dependent anemia. Brindled (Mobr/y) mice, which are not anemic, were compared to their normal brothers (Mo+/y) as well as to anemic suckling mice that were copper-deficient (-Cu) because their dams were consuming a diet low in copper and a fourth group of suckling mice that served as dietary controls (+Cu). Compared to +Cu and Mo+/y mice, -Cu mice were smaller and exhibited cardiac hypertrophy and significant atrophy of lymphoid tissues (spleen and thymus), Mobr/y mice were also small and demonstrated modest atrophy of both liver and spleen. Cu levels were decreased in all -Cu mouse tissues studied, whereas Fe levels tended to be unaltered. Mobr/y mice also exhibited lower tissue Cu levels in soft tissues, except for kidney and small intestine; however, Cu levels in Mobr/y mice were greater than in -Cu mice. Functional copper deficiency was demonstrated in -Cu tissues by decreases in cytochrome c oxidase (CO) and cuprozinc-superoxide dismutase (SOD). The magnitude of the change was tissue specific. Mobr/y tissues, which were low in Cu, also exhibited decreased SOD and CO activity. However, the drop in Mobr/y tissue was less than in -Cu tissue. This was most pronounced in bone marrow, where both CO and SOD were four times higher in Mobr/y than in -Cu mice. Both Mobr/y and -Cu mice had low serum ceruloplasmin activities. The presence of anemia in -Cu mice and the absence of anemia in Mobr/y mice may result from a more severe copper-deficient state in erythropoietic tissues in -Cu mice rather than from differences in ceruloplasmin activity.