Significance of portal venous VEGF during liver regeneration after hepatectomy.
BACKGROUND
Although some studies have hypothesized portal venous blood is important for liver regeneration, no studies have established organs whose venous effluent flow into the portal vein secrete liver regenerating factors into the portal vein during liver regeneration. The aim of this study was to elucidate up-regulation of vascular endothelial growth factor (VEGF) in the portal vein, and expressions of hepatic regenerating factors in organs whose venous effluent flows into the portal vein during liver regeneration.


METHODS
VEGF protein in systemic and portal venous blood, as well as expression of VEGF, hypoxia-inducible factor-1alfa (HIF-1alpha), hepatocyte growth factor (HGF), and HGF activator (HGFA) mRNA were evaluated in the regenerating liver, spleen, and intestine following 70% partial hepatectomy (PHx) in rats.


RESULTS
The portal VEGF protein level was significantly higher than the systemic level post-PHx (portal/systemic at 72, 120, and 168 h post-PHx: 17.2/13.0, 20.2/12.8, and 24.0/14.7 pg/mL; P = 0.003, P = 0.022 and P = 0.032, respectively). VEGF mRNA expressions were significantly higher in the liver (P = 0.000027: 168 h), spleen (P = 0.000059: 72 h) and intestine (P = 0.01: 24-72 h) post-PHx compared with pre-PHx. HIF-1alpha, HGF, and HGFA mRNA expressions in the liver, intestine, and spleen were also significantly higher post-PHx compared to pre-PHx.


CONCLUSIONS
Portal VEGF was significantly higher than systemic VEGF, and expressions of VEGF, HIF-1alpha, HGF, and HGFA mRNA in the liver, spleen and intestine were also up-regulated during liver regeneration. These results suggest that hepatic regenerating factors derived from the spleen or intestine may contribute liver regeneration.
Yamamoto
Chiduru
C
Department of Hepatobiliary and Pancreatic Surgery, Mie University Graduate School of Medicine, Tsu, Japan.
Yagi
Shintaro
S
Hori
Tomohide
T
Iida
Taku
T
Taniguchi
Kentaro
K
Isaji
Shuji
S
Uemoto
Shinji
S
D000818:Animals; D017931:DNA Primers; D005784:Gene Amplification; D005786:Gene Expression Regulation; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics; D007700:Kinetics; D008099:Liver / Q000502:physiology; D008115:Liver Regeneration / Q000235:genetics / Q000502:physiology*; D016031:Liver Transplantation / Q000502:physiology; D008297:Male; D011168:Portal System / Q000502:physiology; D011169:Portal Vein / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000097:blood / Q000235:genetics*
D017931:DNA Primers; C497444:Hif1a protein, rat; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A