Hepatic changes in male ACI/N rats on low dietary levels of sterigmatocystin

Three groups, each consisting of 36 male ACI/N rats, were fed a diet containing 10, 1, or 0.1 ppm sterigmatocystin for life span. There was no dose--effect relationship on tumor incidence or mean survival time. Toxic and preneoplastic changes of the parenchyma such as hyperplastic foci were observed in the liver of experimental groups with dose--effect relation, but hepatocellular carcinoma was observed only in one rat of 10 ppm group. In addition to these lesions, hemangiosarcomas of the liver were also observed in the highest and middle-dose groups, 3/26 and 1/29, respectively. There was not significant difference in the incidence of other tumors in experimental or control groups.