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.
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.