Interindividual differences in the activation of two hepatic carcinogens to mutagens by human liver

The possibility that the presence of malignant disease can influence the metabolic activation of two carcinogens, 2-acetylaminofluorene and aflatoxin B1, has been investigated in a group of patients with secondary carcinoma of the liver. Mutagenic activation by subcellular fractions from biopsy samples from the patients was determined in the Ames/Salmonella test and the results compared with those obtained from a group of control patients. No significant differences were observed between the groups of patients in their ability to activate the two compounds to mutagenic metabolites. A tenfold range in ability to activate aflatoxin B1 was observed whereas only a threefold range was obtained with 2-acetylaminofluorene. Human liver activates aflatoxin B1 approximately 100 times more efficiently than 2-acetylaminofluorene, a proven carcinogen in many species. This raises the question of the true risk to man from hepatocarcinogenicity from aflatoxin B1.