DISPOSITION OF TETRACHLORO-(C-14)-ETHYLENE FOLLOWING ORAL AND INHALATION EXPOSURE IN RATS

Tetrachloro[14C]ethylene (Perc) was administered to adult, male Sprague-Dawley rats by gavage (1 or 500 mg/kg) or by inhalation (10 or 600 ppm, 6 hr duration). Within 72 hr following oral administration of 1 mg/kg or inhalation of 10 ppm [14C]Perc, approximately 70% of the body burden of radioactivity was excreted in expired air as Perc, 26% as 14CO2 and nonvolatile metabolites in urine and feces, and 3 to 4% remained in the carcass. After oral administration of 500 mg/kg or inhalation of 600 ppm [14C]Perc, 89% of the radioactivity was recovered in expired air as Perc, 9% as 14CO2 and urinary and fecal metabolites, and 1 to 2% remained in the carcass. The major urinary metabolite of Perc was identified as oxalic acid. Pulmonary elimination of Perc was monophasic with a half life (t 1 2) of approximately 7 hr independent of dose or route of administration. Radioactivity remaining in the carcass 72 hr after exposure by either route was primarily distributed within liver, kidney and fat tissue. In liver, 85 to 90% of the total radioactivity was cleared within 72 hr following inhalation exposure to 10 or 600 ppm. Nonextractable radioactivity, either bound or incorporated into hepatic macromolecular material, was cleared at a slower rate. The tissue concentration of nonextractable radioactivity was dependent upon body burden and metabolic capacity but apparently not upon route of administration. Thus, the data indicate that disposition of Perc is a saturable, primarily dose-dependent process in rats. © 1979.