Promotive action of 2-acetylaminofluorene on hepatic precancerous lesions initiated by diethylnitrosamine in rats: Molecular study

Table 1 Expression rate of hepatocytes positive for proliferating cell nuclear antigen was calculated as number of positive field expression in 10 fields per rat liver tissue

Group	10 wk duration	16 wk duration
DEN	+	++
DEN + 100 AAF	+	++
DEN + 200 AAF	++	+++
DEN + 300 AAF	++	+++

+: Positive expression found in 1-3 fields; ++: Positive expression found in 4-6 fields; +++: Positive expression found in 7-10 field. DEN: Diethylnitrosamine; AAF: Acetylaminofluorene.