Neutrophil elastase inhibitor reduces neutrophil chemoattractant production after ischemia-reperfusion in rat liver

Abstract

Background & aims: Neutrophils are important in the development of tissue injury induced by ischemia-reperfusion. The ability of an inhibitor of neutrophil elastase (ONO-5046) to protect against ischemia-reperfusion injury in rat liver was investigated by measuring serum concentrations of cytokine-induced neutrophil chemoattractant.

Methods: Liver ischemia was induced in rats by occluding the portal vein for 30 minutes, and ONO-5046 or anticoagulants were injected intravenously 5 minutes before vascular clamping.

Results: Serum concentration of cytokine-induced neutrophil chemoattractant increased after reperfusion, reached a maximum at 6 hours, and then gradually decreased. However, pretreatment of animals with heparin (50 U/kg), antithrombin III (250 U/kg), or ONO-5046 (10 mg/kg) resulted in significantly smaller increases in the serum concentration of cytokine-induced neutrophil chemoattractant after reperfusion. Pretreatment with both ONO-5046 and heparin, or both ONO-5046 and antithrombin III, produced additive effects. Pretreatment of rats with both ONO-5046 and heparin or both ONO-5046 and antithrombin III also inhibited the increase in cytokine-induced neutrophil chemoattractant mRNA in liver. These combined treatments significantly reduced the increases in both the number of neutrophils accumulated in the liver and the hepatic activity of myeloperoxidase.

Conclusions: Cytokine-induced neutrophil chemoattractant production after ischemia-reperfusion in the liver is mediated by neutrophil elastase and activation of coagulation within the hepatic microcirculation.