Carcinomas of the liver in rats ingesting kepone.

Young male and female albino rats ingested 0, 1, 5, 10 or 25 ppm Kepone, an organochlorine pesticide, in the diet for two years. Carcinomas of the liver, as well as hyperplastic nodules and moderate and severe diffuse hyperplasia were observed in Kepone-treated rats. Such hepatic lesions were not seen in control rats. Female rats ingesting Kepone were more susceptible than male rats to hepatic carcinogenesis. Rats ingesting 50 or 80 ppm Kepone developed severe diffuse hepatic hyperplasia and did not survive beyond 26 weeks.