The Reaction of Specific Antibody with 2-Acetylaminofluorene Fixed in Liver Cells1

Rabbit antibody specific to the 2-azofluorenyl group (anti2-AzF antibody) was used to investigate the behavior of cellular components capable of binding 2-acetylaminofluorene (2-AAF) in rat livers during the chemical carcinogenesis. The fixation of the anti-2-AzP antibody in vitro by liver sec tions of rats fed or injected with fluorenyl derivatives was quan titatively measured by the radioiodine-labeled antibody technic. The anti-2-AzF antibody was fixed to a higher extent at earlier stages of 2-AAF feeding than at later stages. No definite fixation of the antibody was observed 2 weeks after completing the feeding schedule of 16 weeks. When rats on normal diet after completing the 2-AAF feeding were injected with 2-AAF and assayed, the antibody reacted more weakly with hepatomatous nodules than with preneoplastic or normal liver, indicating the presence of carcinogen-binding components at the preneoplastic stage. The concentration of these components in hepatomatous nodules was much lower. Cellular distribution of the carcinogen in the livers of these rats was determined by fluorescent antibody technic. The results clearly demonstrated that carcinogen-binding components of hepatic cells are present at a particularly high concentration in the cell boundary and the perinuclear zone and that these com ponents are partially deleted in cells of hyperplastic nodules which appear at the later stage of the 2-AAF feeding, and almost completely deleted in hepatomatous cells.