Incorporation of uranium. I. Distribution of intravenously and intraperitoneally injected uranium.

The distribution of uranium in mice following intravenous and intraperitoneal injections of uranyl nitrate and uranyl tricarbonate was studied by autoradiographic and fluorometric methods at different times after administration. The investigations revealed a higher retention of uranium in the spleen and bone than in other organs, including the kidneys. We have been able to show that even very small amounts of uranium give rise to ischaemia in the kidney. A higher initial uptake was found in the juxtamedullary zone than in the more peripheral parts of the renal cortex. The retention, however, was higher in the peripheral cortex. This may explain the fact that the first observable damage in the kidney appears in the juxtamedullary zone. The connexion between blood supply and uranium uptake and retention in different zones of the renal cortex is discussed with special regard to the toxicological consequences of uranium incorporation and to the possibility of accelerating the excretion of uranium.