Role of inducible nitric oxide synthase in liver ischemia-reperfusion injury in rats

Objective To study the role and mechanism of inducible nitric oxide synthase(iNOS) in liver ischemia-reperfusion injury in rats.Methods An ischemia-reperfusion(IR) process of 1 h ischemia and then 6 h reperfusion was performed on 30 male Sprague-Dawley rats.The rats then were randomly divided into 3 groups: IR(control) group,aminoguanidine(AG) group,and lipopolysaccharide(LPS) group,10 for each.The 3 groups were injected 10 μL/kg of saline,100 mg/kg of AG and 10 mg/kg of LPS through tail vein,respectively.The expression of the iNOS mRNA and protein,the level of alanine aminotransferase(ALT) in serum,malondialdehyde(MDA) and superoxide dismutase(SOD) in liver tissues were determined and histology was observed in 6 hours after reperfusion.Results Compared to the control group,the expression of the iNOS mRNA and protein was lower in the AG group but higher in the LPS group,both with statistically significant difference(P0.05).The level of ALT in serum samples and MDA in liver of the AG group were significantly higher than that of the control group(P0.05) and the level of SOD was lower(P0.05),but the changes of these indices were opposite in the LPS group.Histology showed an edema in the control group.The edema was ameliorated in the AG group,while severed and even degenerated in the LPS group.Conclusion The elevation of iNOS contributes to the severe ischemia-reperfusion injury and the effect may be caused by influencing the oxidation and reduction environment.