Expression and role of inducible nitric oxide synthase in ischemia-reperfusion liver in rats

<正> OBJECTIVE: To investigate the expression and the role of iNOS expression in hepaticischemia-reperfusion (L/R) injury.METHODS: Male Wistar rats were subjected to 30-minute hepatic ischemia, then iNOS protein andiNOS mRNA expression in liver tissue was assessed by Western blot and RT-PCR analysis respectivelyat different time points after reperfusion. The effects of L-NAME (Nω-nitro-L-arginine methyl ester, anonselective NOS inhibitor) or AE-ITU (aminoethytl-isothiourea, a relative selective inhibitor of iNOS)treatment were also evaluated.RESULTS: High levels of iNOS protein and mRNA expression were detected in the liver tissue subjectedto I/R, but not in the sham-operated rats. iNOS protein and iNOS mRNA expression reached a maximumon the first day after reperfusion and decreased later. The levels of iNOS protein and iNOS mRNAdisappeared on 7th, 3rd day after reperfusion respectively. The high iNOS expression was correlated withhepatic dysfunction. L-NAME administration worsened hepatic dysfunction induced by hepatic I/R. Incontrast, AE-ITU administration showed mild protective effects against hepatic dysfunction induced byhepatic I/R.CONCLUSION: Ischemia-reperfusion may induce or up-regulate the expression of iNOS protein andiNOS mRNA, which is detrimental to hepatic I/R injury.