Nuclearity and BrdU Labeling of Rat Hepatocytes in Cytocentrifuge Preparations of Freshly Isolated Hepatocytes with Cumulative Labeling of Bromodeoxyuridine

抄録

Hepatocytes with 2 or more nuclei are seen at a certain percentage in the normal rat liver and show changes according to mitogenic stimuli including regeneration from injury. In the present study, analysis of nuclearity and cell kinetics of hepatocytes was conducted by combining cytocentrifuge preparations of isolated hepatocytes and bromodeoxyuridine (BrdU) cumulative labeling in 6-week-old female Sprague-Dawely rats at periods of 7, 14, and 28 days, respectively. In cytocentrifuge preparations, hepatocytes with intact cytoplasms were obtained, from which nuclearity was clearly and readily defined. The majority of hepatocytes were mononuclear or binuclear. The percentage of cells with 3 or more nuclei was very low. The percentages of each nuclearity class were similar throughout all labeling periods. The ratio of mononuclear to binuclear cells was approximately 6:4. The BrdU labeling index per total nuclei increased according to the labeling period. For the labeling index of each cell type, the number of BrdU positive mononuclear cells and binuclear cells with 2 positive nuclei (WP) increased according to the labeling period at a ratio of approximately 3:1. In the binuclear cells, WP cells and cells with 2 negative nuclei were dominant, whereas, cells with 1 positive and 1 negative nuclei were very rare. From these observations, the present method was thought to be well suited for analysis of nuclearity and cell kinetics in hepatocytes and may be useful for analysis of changes in the liver induced by various compounds.