Oval cells offer the liver a second chance to regenerate. Because human livers have the power to regenerate, a patient’s diseased liver can be replaced by compatible liver tissue from a living donor (usually a genetically close relative, whose own liver grows back). Human livers regenerate more slowly than those of mice, but function is restored quickly (Pascher et al. 2002; Olthoff 2003). In addition, mammalian livers possess a “second line” of regenerative ability. If the hepatocytes are unable to regenerate the liver sufficiently within a certain amount of time, the oval cells divide to form new hepatocytes. Oval cells are a small progenitor cell population that can produce hepatocytes and bile duct cells. They appear to be kept in reserve and are used only after the hepatocytes have attempted to heal the liver (Fausto and Campbell 2005; Knight et al. 2005).
Fausto, N. and J. S. Campbell. 2005. The role of hepatocytes and oval cells in liver regeneration. Mech. Dev. 120: 117–130.
Knight, B., V. B. Matthews, J. K. Olynyk and G. C. Yeoh. 2005. Jekyll and Hyde: Evolving perspectives on the function and potential of the adult liver progenitor (oval) cell. BioEssays 27: 1192–1202.
Olthoff, K. M. 2003. Hepatic regeneration in living donor liver transplantation. Liver Transpl 9: S35–S41.
Pascher, A. and 9 others. 2002. Donor evaluation, donor risks, donor outcome, and donor quality of life in adult-to-adult living donor liver transplantation. Liver Transpl 8: 829–837.