alpha-fetoprotein-containing cells in the early stages of liver carcinogenesis induced by 3'-methyl-4-dimethyl-aminoazobenzene and 2-acetylaminofluorene.

The morphology of rat liver cells containing alpha-feto-protein (AFP) during early stages of carcinogenesis induced by 3'methyl-4-dimethylaminoazobenzene and 2-acetylaminofluorene was investigated. Indirect immunofluorescence was used to detect AFP. AFP was not found in the cells of hyperplastic nodules but was present in the cells located in areas of transitional cell proliferation. A large proportion of the AFP-positive cells formed gland-like structures. The cells containing AFP were at various levels of differentiation according to morphological criteria. Poorly differentiated, small, basophilic cells were predominant amont the AFP-positive population. The most highly differentiated AFP-positive cells had the morphology of hepatocytes.