Abstract
Changes of ploidy pattern of the rat liver during postnatal growth and the regeneration after partial hepatectomy are studied.During postnatal growth a rapid development of Tetraploid Class was noted in peripheral and intermediate zones of the hepatic lobules, but the concurrent decrease of binucleate cells (after 5 weeks postnatally) was small.
Ploidy pattern of the regenerating rat liver showed bimodal, transient increase of Higher Ploidy cells (containing more DNA per cell than Tetraploid cells) and the rate of increase was much higher in the two zones mentioned above.There was poor inverse relations between the shifts of mononucleate and binucleate cells.Polyploidization of the hepatic cells may signify the maturity and the activity of the tissue, and there may be some mechanisms of polyploid formation other than the fusion of binucleate cells.
