Beneficial effects of hyperbaric oxygen pretreatment on massive hepatectomy model in rats.
BACKGROUND
The purpose of this study was to investigate the impact of hyperbaric oxygen (HBO) pretreatment in massive hepatectomy model, a surrogate model of small-for-size graft, using rats.


METHODS
(Experiment I) Rats were divided into the following four groups: HBO (-), HBO-1D (day), HBO-3D, and HBO-5D. Samples were taken after the completion of HBO pretreatment, and the following parameters were evaluated: reverse transcription polymerase chain reaction and immunohistochemical staining for HSP 70 and HO-1; biochemical parameters; and liver weight to body weight ratio (Lw/Bw ratio). (Experiment II) Rats were divided into four groups as follows; 70% hepatectomy (Hx), 70% Hx-HBO, 90% Hx, and 90% Hx-HBO group. Samples were taken 12, 24, 48, and 72 hr after hepatectomy and the following parameters were investigated: biochemical analysis; Lw/Bw ratio; PCNA labeling index; and survival.


RESULTS
(Experiment I) The expression of HSP70 mRNA was significantly increased in the HBO-3D group compared with the HBO (-) group (P<0.05). HSP70- and HO-1-positive hepatocytes were significantly increased in the HBO-3D group compared with the HBO (-) group (P<0.05). (Experiment II) Transaminases were significantly decreased in both 70% and 90% Hx-HBO groups compared with Hx alone group (P<0.05). The Lw/Bw ratio and PCNA labeling index of the 90% Hx-HBO group were significantly increased compared with the 90% Hx group, 24, 48 and 72 hr after hepatectomy (P<0.05). The survival rate in the 90% Hx-HBO group was significantly higher than that in the 90% Hx group (P=0.01).


CONCLUSIONS
HBO pretreatment had beneficial effects in a massive hepatectomy model in rats via the induction of HSP70 and HO-1.
Mori
Hiroki
H
Department of Surgery, Institute of Health Biosciences, The University of Tokushima, Tokushima, Japan.
Shinohara
Hisamitsu
H
Arakawa
Yusuke
Y
Kanemura
Hirofumi
H
Ikemoto
Tetsuya
T
Imura
Satoru
S
Morine
Yuji
Y
Ikegami
Toru
T
Yoshizumi
Tomoharu
T
Shimada
Mitsuo
M
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001663:Bilirubin / Q000097:blood; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D051547:Heme Oxygenase-1 / Q000235:genetics; D006498:Hepatectomy / Q000379:methods*; D006931:Hyperbaric Oxygenation / Q000379:methods*; D008297:Male; D023421:Models, Animal; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D051547:Heme Oxygenase-1; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D001663:Bilirubin