Increased polyploid incidence is associated with abnormal copper accumulation in the liver of LEC mutant rat

Long-Evans Cinnamon (LEC) rats are deleted at the p-type copper transport A TPase gene (Atp7b), so that they exhibit abnormal hepatic copper concentrat ion. In this study, it was confirmed that LEC rat liver possesses a feature of increase in polyploid. Furthermore, a segregation analysis using backcr osses between LEC and F344 normal rats showed that the increased polyploid incidence is strongly associated with excessive copper content in their liv er. These results should demonstrate that copper cytotoxicity leads to the impairment of mitotic progression, resulting in the increase of polyploid i n the liver of LEC rats.