DISTRIBUTION AND EXCRETION OF RADIOMANGANESE ADMINISTERED TO THE MOUSE

In order to elucidate the physiological meaning of trace elements in living organism, studies on radiomanganese were carried out in the mouse with special reference to its distribution and excretion. After the nuclear reaction 52 Cr(d, 2n) 52 Mn by the cyclotron, 52 Mn was separated by the radiocolloid method. Carrier‐free 52 MnC1 2 was dissolved in 0·9 per cent NaCl solution (F‐solution), and purified MnCl 2 was added as carrier to the above solution (C‐solution). Each solution was injected into a tail vein of an adult male mouse. In both experiments with F ‐ and C‐solution, the amount of radiomanganese found in the various tissues after 24 hr. was in decreasing order as follows: kidney, pancreas, liver, intestine, skin, muscle, brain and blood. As the carrier manganese included in C‐solution increased, the amount of radiomanganese in tissues was generally lowered. Such a carrier‐effect was dependent on the concentration of administered carrier. In bone the carrier‐effect was not apparent. The amount of radiomanganese in all the tissues appeared to attain its maximum within 2 hr. after administration in all experiments. However, in the experiment with F‐solution, the elimination of radiomanganese from the tissues proceeded more rapidly. The excretion of radiomanganese mainly proceeded through the feces, and the rate of excretion reached its peak about 10 hr. after administration. Such a rapid excretion probably takes place through a pathway from the intestinal epithelium into the alimentary canal. The amount of excretion for 7 days was 93 and 60 per cent of administered radiomanganese for the experiments with F ‐ and C‐solution, respectively.