Effect of portal hemodynamics on liver regeneration studied in a novel portohepatic shunt rat model.
BACKGROUND
The role of portal hemodynamics on liver regeneration after partial hepatectomy is not fully understood. The aim of our study was to characterize the effects of portal hemodynamics using a novel rat model.


METHODS
We established a rat model of a portohepatic shunt with a 70% hepatectomy (PHS model), in which the portal pressure remained stable during and after the 70% hepatectomy. To assess the effect of portal hemodynamics on liver injury and regeneration in the first 24 hours, we compared PHS rats with those with a simple 70% hepatectomy.


RESULTS
Biochemical and histopathologic changes were similar between the 2 groups. Liver weight increased in the control, whereas it did not in the PHS group (P = .0021). Hepatocytes were enlarged in the control but not in the PHS group, although DNA synthesis was similar in both groups. Apoptotic hepatocytes increased markedly in PHS at 24 hours, whereas minimal apoptosis was noted throughout the course of the study in the control group. Hepatocyte growth factor increased similarly, except that it was not activated in PHS.


CONCLUSIONS
Our results suggested that a portal hyperdynamic state early after a 70% hepatectomy was necessary for liver regeneration through activation of hepatocyte growth factor, promoting hepatocyte hypertrophy and avoiding apoptosis, while DNA synthesis in hepatocytes was independent of portal hemodynamics.
Marubashi
Shigeru
S
Department of Surgery and Clinical Oncology, Osaka University, Graduate School of Medicine, Osaka 565-0871, Japan.
Sakon
Masato
M
Nagano
Hiroaki
H
Gotoh
Kunihito
K
Hashimoto
Kazuhiko
K
Kubota
Masaru
M
Kobayashi
Shogo
S
Yamamoto
Shinji
S
Miyamoto
Atsushi
A
Dono
Keizo
K
Nakamori
Shoji
S
Umeshita
Koji
K
Monden
Morito
M
D000818:Animals; D017209:Apoptosis; D006439:Hemodynamics / Q000502:physiology*; D006498:Hepatectomy; D008099:Liver / Q000166:cytology / Q000502:physiology / Q000601:surgery*; D008115:Liver Regeneration / Q000502:physiology*; D011168:Portal System / Q000502:physiology*; D011169:Portal Vein / Q000601:surgery*; D011170:Portasystemic Shunt, Surgical / Q000379:methods*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors