Production of Cirrhosis and Liver Tumors in Male Rats Using High Dosages of 2-Acetylaminofluorene.

Abstract

(1) Histological changes in the liver during the administration period of 2-acetylaminorluorene were studied by means of repeated partial hepatectomies. (2) It was observed that malignant liver tumors produced by 2-AAF are preceded by a certain pattern of changes in liver structure, beginning with subacute necrosis, nodular hyperplasia, and cirrhosis. (3) Although these findings confirm the frequency of hyperplasia preceding malignant tumor formation, the actual conversion to malignancy does not seem to follow necessarily the condition of hyperplasia and/or benign neoplasia. (4) Repeated partial hepatectomies did not increase the incidence or accelerate the occurrence of hepatic tumors. (5) The percentage of liver tumors was considerably higher in males, which were found to be more susceptible than female rats to the hepatotoxic action of 2-AAF. (6) The incidence of liver tumors apparently depends on the production of hepatic damage, which has a localizing effect on the carcinogenic action of 2-AAF.