Expression of a 65 kda oncofetal phosphoprotein in the altered hepatic foci of rats fed 2-acetylaminofluorene followed by phenobarbital

The altered hepatic foci (AHF) developed in livers of Sprague-Dawley male rats,by acetylaminofluorene/phenobarbital protocol, were analyzed on paraffin sections for gamma-glutamyl-transpeptidase, glutathione S-transferase P and 65 kDa oncofetal protein (p65). 92% percent of the foci were GST-P-positive, 89% of those were also positive for GGT but only 10-12% were positive for p65. Comparison of tissues from different sources such as fetal and normal liver, foci, nodules, surrounding parenchyma and hepatocellular carcinomas revealed the presence of p65 protein in all tissues except normal rat liver and liver parenchyma surrounding the focal lesions.