The Fate of Inhaled and Ingested Tritiated Terphenyls in Mice

Abstract

Inhalation and ingestion of tritiated reactor coolant (hydrogenated terphenyls HB-40) have been used to study, by scintillation counting, the clearance of terphenyls from mice, and to identify, by autoradiography, the cellular distribution of labeled coolant in various organs. Following inhalation, particles deposited in the lung were rapidly cleared; pulmonary radioactivity was always lower than that of gut, probably because larger particles trapped and cleared from the upper respiratory tract were swallowed. After ingestion, radioactivity in gut, liver, and kidney was maximal at four to five hours, fell dramatically by one day, and had almost disappeared by one week. Isotopic uptake was low and diffuse in hepatocytes; whereas in kidney, label was found in tubules rather than in glomeruli. This pattern of labeling corresponds to the known differential susceptibility of these cells to large doses of ingested coolant.