[Polyploidizing mitoses and the biological meaning of polyploidy in liver cells].
The ontogenetic polyploidization of hepatocytes is regarded, within which normal mitoses are changed to polyploidizing mitoses, and diploid hepatocytes transform into polyploid mono- and binuclear cells. A new hypothesis is put forward of the biological significance of the liver cell polyploidy. The hypothesis takes into account a high level of spontaneous chromosomal aberrations in mitotic hepatocytes. The chromosome structural changes interfere with mitosis resulting in the chromosomal imbalance. Polyploidy bestows for hepatocytes a tolerance towards a chromosomal imbalance. Some implications of the hypothesis are discussed: unbalanced genome of hepatocytes after the treatment with mutagens and mitotic stimulators; the reasons of liver cell polyploidy differences in mammalian species; mechanisms of radioresistance of hepatocytes. Chromosomal imbalance of polyploid hepatocytes is assumed to be the basis for wome chronic liver diseases in man.
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002908:Chronic Disease; D004247:DNA / Q000235:genetics; D004171:Diploidy; D005838:Genotype; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology* / Q000254:growth & development / Q000648:ultrastructure; D008107:Liver Diseases / Q000209:etiology; D008115:Liver Regeneration; D008938:Mitosis; D011123:Polyploidy; D011836:Radiation Tolerance; D013045:Species Specificity
D004247:DNA
Poliploidiziruiushchie mbitozy i biologicheskiĭ smysl poliploidii v kletkakh pecheni.