Effects of Postprocessing of Different Dosages of Vitamin C on Renal Ischemia-reperfusion Injury in Rats

Objective To investigate the effects of postprocessing of different dosages of vitamin C on renal ischemia-reperfusion injury and the relevant mechanisms of NF-κB p65 in rats.Methods Thirty adult male SD rats were divided randomly into groups Sham,renal ischemia-reperfusion group (RIR),postprocessing of low-dosage Vitamin C (LVcPO),middle-dosage (MVcPO) and high-dosage (HVcPO),6 in each.Serum was collected to detect blood urea nitrogen (BUN) and creatinine (Cr) at hours 2 after reperfusion,and renal tissues were taken to perform homogenate to determine the levels of superoxide dismutase (SOD) activities,malondialdehyde (MDA) and NO.The NF-κB p65 levels in renal tissue were evaluated by immunohistochemical method.Results The levels of BUN,Cr,renal tissue MDA,NO increased (P0.01)but SOD decreased in group RIR(P0.01)as compared with group Sham;those of groups LVcPO,MVcPO,HVcPO decreased(P0.05),but SOD increased(P0.05),when compared with group RIR.NF-κB p65 of group RIR had remarkable positive expression in renal tubular epithelial cells,with a large number of brown-yelllow granules distributing in a diffusing state.Positive cells were more in groups LVcPO,MVcPO,HVcPO than in group Sham,but fewer than in group RIR,the fewest in group HVcPO.Conclusion NF-κB p65 expression and changes of NO level in renal tisssues are closely related to ischemia-reperfusion-induced renal tissue damage.Postprocessing of different dosages of vitamin C inhibits NF-κB p65 expression and reduces NO level,thus to protect effectively renal tissues.It has been found that postprocessing of high-dosage vitamin C can effect more remarkably.