Analysis of DNA Ploidy Patterns and Nuclear Morphometry in Diethylnitrosamine Induced Hepatocyte Nodules and Hepatocellular Carcinoma of Rats

ABSTRACT

This study was designed to answer the question; (1) How does the DNA ploidy pattern change in hepatocarcinogenesis? (2) How does the nuclear morphology change in hepatocarcinogenesis? Diethylnitrosamine(DEN) (16.5 mg per kg) was subcutaneously injected to female Sprague-Dawley rats(150~200g) by weekly interval for 30 weeks. DNA ploidy and parameters of nuclear morphology were measured by image analyser(IBAS 200, Kontron, FRG). The DNA ploidy pattern was divided into three basic patterns(diploid, polyploid, and aneuploid modes). In 8 cases of saline-injected control rats, the DNA histograms showed all polyploid pattern. Inhepatocyte nodules(hyperplastic nodules), DNA diploidy was the most frequent pattern, being followed by polyploid and aneuploid DNA patterns, contrast to hepatocelular carcinomas in which polyploid DNA pattern was most frequently noted being followed by diploid and aneuploid DNA pattern. Although the nuclei of hepatocytes in hepatocyte nodules and hepatocellular carcinomas were larger and more pleomorphic than those of normal hepatocytes, they were as same as those of normal hepatocytes in regard to nuclear hyperchromasia. DNA content, which was increased in hepatocarcinogenesis, was significantly related to the nuclear area.