DNA Ploidy and S-Phase Fraction in Proliferative Hepatic Lesions of Rat Liver Induced by Dietylnitrosamine and Partial Hepatectomy

ABSTRACT

We have investigated the changes of DNA ploidy and S-phase fraction in proliferative lesions of rat liver. Proliferative lesions were induced by diethylnitrosamine and partial hepatectomy. DNA ploidy was measured by flow cytometer, and S-phase fraction was measured by in situ bromodeoxyuridine(BRdU)-anti BRdU monoclonal antibody techniques. Normal liver and initiated lesion revealed DNA diploidy or DNA tetraploidy. Hepatocyte nodule (NODULE) and hepatocelular carcinoma (HCC) revealed DNA diploidy, tetraploidy or aneuploidy. S-phase fraction was 1.0+/-0.9, 1.0+/-0.9m 3.7+/-2.3, 5.5+/-4.9, and 13.8+/-11.6 in normal liver, initiated lesion, NODULE not associated with HCC, NODULE associated with HCC, and HCC, respectively. In NODULE associated with HCC, it was widely distributed, ranging from 0.8 to 15.5%. In conclusion, S-phase fraction appeared to be increased as the hepatocarcinogenesis proceeded, but DNA ploidy did not. There was a heterogeneity of DNA ploidy and S-phase fraction in the proliferative hepatic lesions.