RESUMO
Objective To investigate the effect of ulinastatin (UTI) preconditioning combined with ischemic preconditioning (IPC) on hepatic ischemia-reperfusion (IR) injury in rats and possible mechanism of action.Methods A total of 50 male Sprague-Dawley rats were randomly divided into sham-operation group,IR group,IPC group,UTI group,and UTI-IPC group (UCI group).Blood samples were collected from the inferior vena cava after surgery and liver tissue samples were also collected.The serum levels of aspartate aminotransferase (AST),alanine aminotransferase (ALT),and tumor necrosis factor-o (TNF-α),the levels of myeloperoxidase (MPO) and nuclear factor-kappa B (NF-κB) in the liver tissue,and wet/dry weight ratio were determined,and pathomorphological changes of the liver tissue were observed under a light microscope.A one-way analysis of variance was used for comparison of continuous data between groups,and the LSD-t-test was used for further comparison between two groups.Results The IR,IPC,UTI,and UCI groups had significantly higher serum levels of ALT,AST,and TNF-α,levels of MPO and NF-κB in the liver tissue,and wet/dry weight ratio than the sham-operation group (all P ＜ 0.05);the IPC,UTI,and UCI groups had significantly lower levels than the IR group (all P ＜ 0.05),the UTI group had significantly lower levels than the IPC group (all P ＜ 0.05),and the UCI group had significantly lower levels than the IPC and UTI groups (all P ＜ 0.05).Liver pathological examination showed that compared with the sham-operation group,the IR,IPC,UTI,and UCI groups had significantly greater liver injury (all P ＜0.05),while the IPC,UTI,and UCI groups had a significantly lower degree of liver injury than the IR group (all P ＜ 0.05),the UTI group had significantly slighter liver injury than the IPC group (P ＜ 0.05),and the UCI group had significantly slighter liver injury than the IPC and UTI groups (both P ＜ 0.05).Conclusion Both UTI and UCI have a protective effect against hepatic IR injury,and the combination of UTI and UCI significantly enhances such protective effect,possibly by inhibiting the expression of NF-κB,reducing the release of TNF-α and MPO,and alleviating liver inflammatory response.