title: Antiangiogenic response after 70% hepatectomy and its relationship with hepatic regeneration and angiogenesis in rats.
abstract: BACKGROUND
  The aim of this study was to evaluate the antiangiogenic response and its relation to regeneration and angiogenesis after 70% hepatectomy in a rat model.
  
  
  METHODS
  Sixty-four Wistar albino rats were included in the study. Animals were allocated into 8 groups (n = 8). After a 70% hepatectomy, liver regeneration, angiogenesis, and antiangiogenic response were evaluated in the remnant liver on days 0, 1, 2, 3, 5, 7, 10, and 14. Regeneration and angiogenesis were determined with immunoreactivity to proliferating cell nuclear antigen and vascular endothelial growth factor. Antiangiogenic response was evaluated by detecting collagen 18 m RNA with reverse transcriptase polymerase chain reaction.
  
  
  RESULTS
  We showed that liver regeneration peaked at day 1, whereas angiogenesis in the periportal and perisinusoidal areas reached their peak values on days 3 and 7, respectively. Both regeneration and angiogenic activity around perisinusoidal hepatocytes returned to basal activity on the day 10. Antiangiogenic response first appeared on day 5, reached a peak on day 10, and returned to basal values on day 14.
  
  
  CONCLUSIONS
  Collagen18 mRNA expression is present in the normal liver during the regenerative process. We suggest that the stimulus that causes the cessation of regeneration process may come from hepatocytes, and collagen 18 produced by hepatocytes may modulate this event by inhibiting the angiogenesis.
authors.affiliation: Department of General Surgery, Medical School, Hacettepe University, Ankara, Turkey. ahmetdogrul@yahoo.com
authors.forename: Ahmet Bulent
authors.initials: AB
authors.lastname: Dogrul
authors.forename: Tamer
authors.initials: T
authors.lastname: Colakoglu
authors.forename: Kemal
authors.initials: K
authors.lastname: Kosemehmetoglu
authors.forename: Esra
authors.initials: E
authors.lastname: Birben
authors.forename: Elif
authors.initials: E
authors.lastname: Yaman
authors.forename: Gokhan
authors.initials: G
authors.lastname: Gedikoglu
authors.forename: Osman
authors.initials: O
authors.lastname: Abbasoglu
mesh_terms: D020533:Angiogenesis Inhibitors / Q000378:metabolism; D000818:Animals; D043170:Collagen Type XVIII / Q000378:metabolism; D005260:Female; D006498:Hepatectomy; D022781:Hepatocytes / Q000378:metabolism; D008099:Liver / Q000098:blood supply*; D008115:Liver Regeneration / Q000502:physiology*; D018919:Neovascularization, Physiologic; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D020533:Angiogenesis Inhibitors; D043170:Collagen Type XVIII; D018809:Proliferating Cell Nuclear Antigen; D042461:Vascular Endothelial Growth Factor A