THE ROLE OF NONGENOTOXIC MECHANISMS IN ARYLAMINE CARCINOGENESIS

The growth of preneoplastic nodules during the feeding of a carcinogen ic 2-acetylaminofluorene (2-AAF) regimen is preceded by several altera tions in the physiologic homeostasis. Many of these alterations can be considered adaptive responses to the drug exposure. One property of A AF could be identified that clearly distinguishes this complete rat li ver carcinogen from at least two other, incomplete rat liver carcinoge ns. Highly specific redox cycling in mitochondria was demonstrated in vitro, and this observation could well contribute an explanation of th e morphologic and histochemical observations in vivo, it is emphasized that nongenotoxic effects may play an important role in the generatio n of tumors by genotoxic carcinogens.