title: Structural analysis of oval-cell-mediated liver regeneration in rats.
abstract: We have analyzed the architectural aspects of progenitor-cell-driven regenerative growth in rat liver by applying the 2-acetaminofluorene/partial hepatectomy experimental model. The regeneration is initiated by the proliferation of so-called oval cells. The oval cells at the proximal tips of the ductules have a more differentiated phenotype and higher proliferative rate. This preferential growth results in the formation of a seemingly random collection of small hepatocytes, called foci. These foci have no clonal origin, but possess a highly organized structure, which shows similarities to normal hepatic parenchyma. Therefore, they can easily remodel into the lobular structure. Eventually, the regenerated liver is constructed by enlarged hepatic lobules; no new lobules are formed during this process. The foci of the Solt-Farber experimental hepatocarcinogenesis model have identical morphological features; accordingly, they also represent only regenerative, not neoplastic, growth.
  
  
  CONCLUSIONS
  Progenitor-cell-driven liver regeneration is a well-designed, highly organized tissue reaction, and better comprehension of the architectural events may help us to recognize this process and understand its role in physiological and pathological reactions.
authors.affiliation: First Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Dezső
authors.forename: Veronika
authors.initials: V
authors.lastname: Papp
authors.forename: Edina
authors.initials: E
authors.lastname: Bugyik
authors.forename: Hargita
authors.initials: H
authors.lastname: Hegyesi
authors.forename: Géza
authors.initials: G
authors.lastname: Sáfrány
authors.forename: Csaba
authors.initials: C
authors.lastname: Bödör
authors.forename: Péter
authors.initials: P
authors.lastname: Nagy
authors.forename: Sándor
authors.initials: S
authors.lastname: Paku
mesh_terms: D015073:2-Acetylaminofluorene / Q000494:pharmacology; D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D001707:Biopsy, Needle; D002454:Cell Differentiation; D049109:Cell Proliferation; D004195:Disease Models, Animal; D006498:Hepatectomy / Q000379:methods; D007150:Immunohistochemistry; D008099:Liver / Q000254:growth & development*; D008113:Liver Neoplasms / Q000473:pathology* / Q000503:physiopathology; D008115:Liver Regeneration / Q000235:genetics / Q000502:physiology*; D008297:Male; D011379:Prognosis; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation; C115011:oval cell marker OV-6; D015073:2-Acetylaminofluorene