Effect Of Ischemic Postconditionging On The Ichemia-reperfusion Injury And The Expression Of NF-κB In Rat Kidney

Objective: To investigate the effect of ischemic postconditioning on the ischemia-reperfusion injury and the expression of NF-κB in rat kidney.Methods: After a 3-day acclimatization, 18 male SD rats were randomly divided into three groups as follows: (1)IR group (n=6): After the left kidney revealed, the left renal artery was separated and reversibly occluded for 60 min followed by 6 h of reperfusion. (2)Ischemic postconditioning group (n=6): After 60 min of the left renal artery occlusion, reperfusion was initiated for 10 s of reperfusion followed by 10 s reocclusion, repeated for six cycles, then subjected to 6 h of reperfusion. (3)Sham group (n=6): Rats underwent the same surgical procedure without obstruction. At the end of reperfusion for 6 h, the blood urea nitrogen (Bun), blood creatinine concentrations( Cr) were measured, the ischemic left renal tissue was collected for the determination of the superoxide dismutase (SOD) activity, malondialdehyde(MDA)content, myeloperoxidase(MPO) activity and the expression of NF-κB; the changes of renal tissue were observed by microscope.Results: The Bun, Cr, MDA and MPO activity were lower(P<0.01) whereas SOD activity was significantly higher(P<0.01) in IPO group than that in IR group.The Bun, Cr, MDA and MPO activity were significantly higher(P<0.01) in IR group than that in Sham group. The SOD activity was lower(P<0.01) in IR group than that in Sham group and the Bun, Cr, MPO activity were higher(P<0.05) in IPO group than that in Sham group. The expression of NF-κB in IR group was significantly stronger than that in Sham group(P<0.01). The expression of NF-κB in IPO group was significantly lower than that in IR group(P<0.01).Conclusion: Ischemic postconditioning attenuates renal ischemia- reperfusiong injury and protects the renal function in rats. The underlying mechanism is related to the enhancement of renal tissue antioxidation, attenuating the lipid peroxidation of renal tissue and inhibiting the infiltration of polymorphonuclear neutrophils and the expression of NF-κB.