Fig. 4.

Representative macroscopic (A) and microscopic (B) features of the liver in the four groups (G1, G2, G3 and G4) demonstrated that no tumors were observed in the liver of control rats (G1) and that multiple white tumor formation was macroscopically observed in the DEN groups G2, G3 and G4. In the histological analysis, the white nodules induced by DEN were hyperplastic nodules (hematoxylin and eosin staining, Bars express 100 µm). Arrows indicate the representative nodules. DEN, diethylnitrosamine.