AUTORADIOGRAPHIC OBSERVATIONS OF MANGANESE IN ADULT AND EMBRYO MICE

Abstract

In connection with the previous work, autoradiographic studies on the distribution of radiomanganese in the mouse tissues were carried out on the adult and the embryo. Results from the adult are summarized as follows. In the kidney, 52 Mn is accumulated more abundantly in the cortex than in the medulla. On precise examinations, 52 Mn is detected remarkably within the epithelial cells of renal tubules but scarcely in the lumen. In the intestinal villi, 52 Mn is found conspicuously in the epithelium and in the mucus cohering to its free surface, which fact may offer a reasonable ground for manganese excretion through intestinal epithelium. 52 Mn is retained in the exocrine portion of the pancreas but not in the islets of Langerhans, and in the liver it is uniformly distributed over the tissues except the lumens of blood vessels. 52 Mn‐retention in the blood is extremely small. In the early embryos, 52 Mn‐concentration is less than in the placental tissues. In the late embryos, 52 Mn‐accumulation in the bone proceeds in parallel with the progress of ossification and 52 Mn‐concentration in the kidney is less than in the liver, conversely in the case of the adult. From the present autoradiographic observations, the physiological meaning of manganese found in tissues has been discussed with reference to the previous work.