Hepatic polyploidy and liver growth control

The onset of cellular polyploidy is recognized in all differ entiated mammalian tissntes. Polyploidy has been noted frequently in the normal liver as well as in pathophysiological states of the liver As insights into the significance of polyploidy accumulate gradually it is becoming clear that cells belonging to high ploidy classes exhibit advancement toward terminal differentiation and cellular senescence with greater probabilities of apoptosis. Involvement of specific genetic abnormalities, such as impaired DNA repair, may lead to hepatocellular polyploidy Working models indicate that extensive polyploidy could lead to organ failure, as well as to oncogenesis with activation of precancerous cell clones. (C) 2000 Academic Press.