Effects of Copper, Iron, and Ascorbic Acid on Manganese Availability to Rats:

AbstractFour experiments were done to characterize the interactions of copper, iron, and ascorbic acid with manganese in rats. All experiments were factorially arranged. Dietary Mn concentrations were <1 μg/g (Mn0) and 50 μg/g (Mn+). Dietary Cu was <1 mg/g (Cu0) and 5 μg/g (Cu+); dietary Fe was 10 μg/g (Fe10) and 140 μg/g (Fe140). Ascorbic acid (Asc) was not added to the diet or added at a concentration of 10 g/kg diet. Experiment 1 had two variables, Mn and Cu; in Experiment 2, the variables were Mn and Asc. In Experiment 3, the variables were Mn, Cu, and Asc; in Experiment 4, they were Mn, Cu, and Fe. Definite interactions between Mn and Cu were observed, but they tended to be less pronounced than interactions between Mn and Fe. Cu depressed absorption of 54Mn and accelerated its turnover. In addition, adequate Cu (Cu+), compared with Cu0, depressed liver, plasma, and whole blood Mn of rats. Absorption of 67Cu was higher in animals fed MnO diets than in those fed Mn+. Ascorbic acid depressed Mn superoxi...