Effects of ischemic preconditioning and ischemic postconditioning on NO in rats undergoing renal ischemic reperfusion

Objective To investigate the effects of ischemic preconditioning and ischemic postconditioning on renal ischemic reperfusion(I-R) injury.Methods Fifty SD rats were equally randomized into five groups of A(sham-operated),B(I-R),C(ischemic preconditioning) D(ischemic postconditioning) and E(combined ischemic preconditioning and postconditioning).The kidneys underwent ischemia for 45 minutes and reperfusion for 24 hours.The levels of superoxide dismutase(SOD),malondialdehyde(MDA),nitric oxide(NO),nitric oxide synthase(NOS) in the kidneys were examined.The pathological changes of the kidneys were observed with hematoxylin-eosin(HE) staining.The figures of PMN and Paller-grades were counted at the same time.The apoptosis rate of tubular epithelial cells was examined by TUNEL.Results Compared to group B,the levels of SCr,BUN and MDA were lower and the activities of SOD,NO and NOS were higher in groups of C,D and E(P0.01).The apoptosis rate of tubular epithelial cells was significantly lower in groups of C,D and E than that in group B(P0.01).Conclusion The ischemic preconditioning and ischemic post-conditioning could protect the kidney from I-R injury,which may be related to an increase of the NOS expression in the kidneys.