Etude Comparee du Métabolisme du Cérium 144 en Fonction de Son État Physico-chimique Chez le Rat

Abstract

The metabolism of ionic and colloidal Ce after intravenous injection in rats was studied over 275 days. Initial tissue distribution and the redistribution during the later phases show considerable differences, particularly in hepatic and bone tissue. While ionic Ce is fixed initially by the hepatocytes, excreted by the bile duct, without secondary transfer into the bone tissue, colloidal Ce is fixed by the cells of the reticulo-endothelial system; after a short period it is returned to circulation and undergoes secondary fixation in the bone tissue and transference to the hepatocytes. These results contradict the hypothesis of the transformation to the colloidal state of Cerium injected into the blood. They emphasize the importance of physico-chemical factors in Ce metabolism, and provide new data on the biological mechanisms involved in the metabolism of this fission product.