2004 Fiscal Year Final Research Report Summary
Contribution of heme oxygenase-1 to the outcome after partial hepatectomy for ischemically damaged steatotic rat liver
| Project/Area Number |
15591395
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Digestive surgery
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| Research Institution | Hamamatsu University School of Medicine |
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Principal Investigator |
SUZUKI Shohachi Hamamatsu University School of Medicine, Second Department of Surgery, Associate Professor, 医学部, 助教授 (20196827)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Satoshi Hamamatsu University School of Medicine, University Hospital, Director, 医学部, 理事 (00090027)
MITSUOKA Hiroshi Hamamatsu University School of Medicine, Instructor, 医学部附属病院, 助手 (10324360)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Steatotic liver / Hepatic ischemia / Reperfusion injury / Hepatectomy / Liver regeneration / Heme oxygenase 1 |
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| Research Abstract |
Background : The pathophysiologic mechanism for the increased vulnerability of steatotic livers to normothermic ischemia and reperfusion injury during partial hepatectomy is yet insufficiently clarified. Heme oxygenase-1 is an antioxidative enzyme which catabolizes heme into biliverdin, carbon monoxide, and iron. This study was conducted to determine the contribution of HO-1 to the outcome after partial hepatectomy for steatotic liver with ischemic insult.
Methods : Male Wistar rats, 4 weeks of age, undergoing splenic transposion to produce spontaneous portosystemic shunt were fed a fat-enriched diet for 4 or 12 weeks to produce the fatty liver. Animals from each group were subjected to 60 minutes of total hepatic ischemia. A two-thirds hepatectomy was performed just before reperfusion. In addition of 7-day survival rates, the assessment of plasma aspartate transaminase (AST) levels, hepatic HO-1 expression, and liver histology was performed 6 hours after reperfusion.
Results : The exten
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t of hepatic steatosis was mild to moderate in animals fed with a fat-enriched diet for 4 weeks and severe in animals fed with a fat-enriched diet for 12 weeks. Six hours after partial hepatectomy, focal necrosis with sinusoidal congestion and neutrophil accumulation was observed in the livers of the control group. Extensive necrosis was seen in severe steatotic liver at the corresponding time. Significantly less histological damage was seen in mild to moderate steatotic liver, when compared with severe steatotic liver. Plasma AST levels in animals fed with a fat-enriched diet for 4 or 12 weeks reached 5517±685 IU/l and 8305±2684 IU/l, respectively, while those in the control group were 3462±1039 IU/l(P<0.01). HO-1 proteins were hardly detectable before induction of hepatic ischemia in the normal liver as well as in the mild and severe steatotic liver. HO-1 protein expression in the severe steatotic liver 6 hours after I/R injury was significantly weaker than those in the normal and the mild steatotic livers. While 7-day survival rates of animals fed with normal chow and a fat-enriched diet for 4 weeks were 50% and 42%, respectively, that of animals fed with a fat-enriched diet for 12 weeks was 25%.
Conclusions : The deficit of HO-1 expression may be a causal factor on poor functional and structural recovery after partial hepatectomy for severe steatotic liver with ischemic insult. The induction of HO-1 system may serve as a novel therapeutic strategy in liver surgery for steatotic liver. Less
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Research Products
(2 results)
