Interdependence of Vitamin B 1 and Manganese. III. Manganese,Copper and Iron Metabolism in Normal Rats

Abstract

The studies presented in this communication form part of an extended investigation of the metabolic interdependence of manganese and vitamin B₁. 1 , 2 , 3

Sixteen male and female rats (Wistar strain) were used. Care of the animals, precautions to avoid unknown Cu intake and methods used in the chemical determinations of Mn, Cu and Fe were the same as those referred to in a previous publication. 3 Feces and food were analyzed for Mn, Cu, and Fe; urine for Mn only. 4 The animals received our stock diet, supplemented with 10% of whole milk powder and 3% of dry brewers' yeast. The Mn content of this diet was 7 y per g. The rats were studied for a control period of 5 weeks. Then followed 4 periods of one month each, when they received (1) small additions of Mn, (2) large additions of Mn, (3) large additions of Mn plus vitamin B₁, and (4) vitamin B₁. Details about Mn and vitamin B₁, administration are given in the preceding paper. 3

Since changes in Fe metabolism were not significant, protocols for Mn and Cu metabolism only are presented.

During the control period when the rats were given a normal diet, supplying about 100 γ of Mn daily, they did not store any Mn. When, however, the Mn content of the food was raised about 50%, 25% of the intake was retained. The addition of 1 mg of Mn per g of food, though raising the intake to over 13 mg of Mn, did not change the percentage of retention. If, however, 400 γ of vitamin B₁ daily were given, the large amount of Mn offered in the diet was utilized to a greater extent.