AIMTo probe into the affection and significance of NO on the expression of P-selectin in renal injury following hind limb ischemia/reperfusion in rats.

METHODSIn accordance with the conventional approaches of our department, the model rats were prepared after they were made to undergo 4 hours or ischemia followed by 4 hours of reperfusion of hind limbs. The Wistar rats were divided into four groups randomly: Control group, LI/R group, L-Arg group and L-NAME group. And then in those four groups of Wistar rats, a series of values of measurement were determined such as: Plasma concentrations of nitric oxide (NO), blood urea nitrogen (BUN) and creatinine (Cr). Furthermore, biochemically there came to the assessment of the values including myeloperoxidase (MPO), NO, total nitric oxide synthase (tNOS), inducible NOS (iNOS) and constitutive NOS (cNOS) of renal tissue in different groups. By the methods of electrophoresis and biochemistry, the urine protein was mensurated. The immunohistochemical method was used to detect the expression of P-selectin protein. The morphologic changes were observed with a microscope.

RESULTSAfter hind limbs had suffered from ischemia/reperfusion for 4 hours, there was the occurrence of a series of results such as in the following which were based on the comparison between plasm of LI/R group and control group. The values of NO, BUN and Cr increased significantly, and the trend of indexes such as NO in renal tissue was similar to that in plasma. The values of MPO, tNOS and iNOS in renal tissue all increased significantly after reperfusion, while cNOS decreased distinctly. The urine protein appeared, especially large molecular weight protein. Renal pathology revealed that after LI/R there were edema and infiltration of polymorphonuclear neutrophil (PMN). Immunohistochemically, the expression of P-selectin was upregulated significantly. Compared with LI/R rats, all injury changes were alleviated in L-Arg group. Morphologic changes were mild. Both the content of urine protein and the percentage of apoptosis cell decreased. The expression of P-selectin was downregulated. In L-NAME group, all injury changes got worse. Immunohistochemical results showed strong positive staining of P-selectin.

CONCLUSIONThe renal injury after LI/R may relate to the strong expression of P-selectin. NO may have protective affection by decreasing the expression of P-selectin and alleviating the adhesion, aggregation and infiltration of neutrophils.