Polyploid accumulation associated with hyper-phosphorylation of histone H1 in hepatocytes of LEC mutant rat.

In this study, we analyzed effects of copper toxicity on the process of mitosis by examining polyploid accumulation and histone H1 hyper-phosphorylation, which result from defects in mitotic completion, in regenerated LEC rat liver. The proportion of polyploids with 8c nuclear DNA content in LEC rats was significantly higher than that in normal rats (P < 0.05). The degree of histone H1 phosphorylation was about 2.5-fold higher in LEC rat than normal rat. These results suggest that the accumulated copper in LEC mutant rat causes the block of mitotic completion in cell cycle.