Single exposure, 14 day, 13 week, and 2 year inhalation studies were performed in F344-rats and B6C3F1-mice to investigate the toxicology and carcinogenicity of tetrachloroethylene (127184) (TCE). In single exposures, doses were 2,445 to 5,163 parts per million (ppm) for 4 hours to rats and 2,328 to 3,786ppm to mice. In 14 day studies, doses were 100 to 1,750ppm 6 hours a day, 5 days a week. In 13 week studies, doses were 100 to 1,600ppm on the same schedule. In 2 year studies, doses were 200 or 400ppm. In 13 week studies, 20 to 70 percent of the animals died at doses of 1,600ppm, and final body weights of survivors were decreased; in 2 year studies, body weights were not affected. Microscopic kidney and liver changes were detected at higher doses in the 13 week study. In 2 year studies, the highest dose reduced the survival of male rats only. There was a correlation between the incidence of mononuclear cell leukemia and the rate of early mortality in high dose rats. Dose related increases in the incidence of hepatocellular carcinomas contributed to the early death rate in mice. Rats exhibited the usual nephropathy associated with aging, as well as renal tubular cell karyomegaly in both sexes. Renal tubular cell adenomas, adenocarcinomas, and testicular interstitial cell tumors were also diagnosed in male rats. Dose related increases were found in the incidences of thromboses and squamous metaplasia in rats of both sexes. Six exposed rats developed gliomas of the brain. In male mice, TCE induced degeneration, necrosis, and nuclear inclusion in the liver. Mice exhibited a dose related increase in renal tubular cell karyomegaly. Ten to 20 percent of mice manifested acute passive congestion of the lungs. Neoplasia increased in all animals. The authors conclude that there is clear evidence of carcinogenicity in male rats, some evidence in female rats, and clear evidence in mice.
10; 6; < ANIMAL >; Activation; Adenoma; Carcinogenesis; carcinogenicity; Carcinogens; Carcinoma; Carcinomas; Cells; Drosophila; Drosophila melanogaster; Exposure; Female; genetic toxicity; Hepatocellular; hepatocellular carcinoma; INCIDENCE; Inhalation; Inhalation Exposure; Inhalation studies; Lethal; Leukemia; Liver; Lymphoma; Male; Males; Metabolic activation; Mice; Mutation; Neoplasm; Neoplasms; Ovary; Rats; Salmonella; Salmonella typhimurium; Sister Chromatid Exchange; Solvents; Sprague-Dawley; Tetrachloroethylene; Toxicology
