Immunodepressants ameliorate normothermic ischemia injury to the rat liver by down-regulating tumor necrosis factor, not by alleviation of lipid peroxidative injury.
Mechanisms by which immunodepressants (Cyclosporine, CsA; FK 506, FK; Azanthioprine, AZA) ameliorate warm ischemic injury of the liver were examined. Female Sprague-Dawley rats were subjected to 60-min of normothermic liver ischemia. Animals were assigned to one of four groups: group I, control with vehicle treatment; groups II, III, and IV, treatment with CsA (10 mg/kg), FK (1 mg/kg), and AZA (1 mg/kg), respectively. The immunosuppressive agents were given per os for 4 consecutive days prior to the induction of hepatic ischemia. In addition to a survival study, plasma levels of endotoxin, serum activities of tumor necrosis factor-alpha (TNF), plasma levels of phosphatidylcholine hydroperoxide (PCOOH) as a lipid peroxide, and serum alanine aminotransferase (ALT) were investigated in blood samples collected from the suprahepatic vena cava. A 7-day survival period was significantly higher in the immunosuppressed animals. Serum TNF levels were elevated and peaked at 3 h following reperfusion. When, the peak values were compared, the animals given immunodepressants had significantly lower levels of TNF (217.0 +/- 40.6 pg/ml for group I, 67.6 +/- 13.7 for group II, 87.9 +/- 28.3 for group III and 89.1 +/- 19.9 for group IV; Mean +/- SEM). Plasma PCOOH levels were also elevated following reperfusion, but with no statistical difference among the groups. Our data suggest that immunodepressants ameliorate warm ischemia/reperfusion injury through modulation of TNF production and not through a diminution of lipid peroxidative injury.
Department of Surgery I, Oita Medical University, Japan.
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Ishii
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Kim
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Tatsuma
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Kawano
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Kai
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Kobayashi
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001379:Azathioprine / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007511:Ischemia / Q000503:physiopathology*; D015227:Lipid Peroxidation; D008099:Liver / Q000098:blood supply*; D010713:Phosphatidylcholines / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000503:physiopathology* / Q000517:prevention & control*; D016559:Tacrolimus / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D007166:Immunosuppressive Agents; D010713:Phosphatidylcholines; D014409:Tumor Necrosis Factor-alpha; C057590:phosphatidylcholine hydroperoxide; D016572:Cyclosporine; D000410:Alanine Transaminase; D001379:Azathioprine; D016559:Tacrolimus