ROLE OF RECEPTORS IN HUMAN AND RODENT HEPATOCARCINOGENESIS

The liver is a major target organ in rodent carcinogenicity assays. Am ongst the agents that are effective in producing rodent liver tumours are many chemicals which are not mutagenic, but are believed to mediat e their effects by promoting the clonal outgrowth of initiated cells. Some of these chemicals, such as dibenzo-p-dioxins and certain PCBs, h ave been demonstrated to interact with specific cellular receptors and receptor binding appears crucial for their tumourigenic activity. Enz yme-altered foci in rat liver may serve as a sensitive means to estima te the promoting activity of these agents in rodents. Mechanistic cons iderations are of relevance when extrapolating these data from rodents to humans.