Studies on the ploidy distributions of the hepatocytes isolated in hepatocarcinogensis of rats

랫드의 간발암화과정에서 분리한 간세포의 ploidy 분포변화에 관한 연구

This study was performed to compare DNA content by flow cytometer (FCM) and glutathione S-transferase placental form (GST-P) positive foci for searching objective and accurated properties of tumor. Sprague-Dawley rats aged six weeks were divided into three groups and group 1 and 2 of rats were given an intraperitoneal injection of diethylnitrosamine at 200mg/kg body weight and group 3 of rats were given saline. Three weeks after beginning of the experiment, all groups were performed partial hepatectomy. Group 1 of rats were begun to feed on diets containing 0.02% 2-acetylaminofluorene as a promoter for six weeks, group 2 and 3 of rats were begun to feed on basal diets. At 4, 6, and 8 weeks after initiation, all groups of rats were killed, livers were extracted for H & E stain, immunohistochemical stain, and DNA ploidy analysis. In quantitative analysis for GST-P positive lesion number and area by using Image Analyzer, group 1 and 2 represented significant difference in comparison with group 3. In ploidy distribution, diploid cells of group 1 and 2 were increased significantly in comparison with those of group 3 at 4, 6, and 8 weeks after initiation, respectively tetraploid cells were reduced. But S-phase cells were not changed significantly. It is concluded that ploidy change by FCM is useful as objective data for early detection in hepatocarcinogenesis. Therefore, methodology and study of DNA content are carried out for more objective and accurate ploidy analysis in liver tumor.