Study On Lymphocyte Function Associated Antigen-1 In Renal Ischemia-reperfusion Injury In Rats

Objective1. To investigate the change of CDlla and myeloperoxidase (MPO) content and renal function during rat renal ischemia-reperfusion injury (IRI), as well as the role of lymphocyte function associated antigen-1 (LFA-1) in renal IRI.2. To investigate the change of CDlla and renal function and histopathologic damage in rat renal tissue of different injured extent, as well as the role of LFA-1 in acute rejection (AR) of renal allograft.Materials and methods1. 45 male Sprague-Dawley (SD) rats were randomly divided into nine groups as follows: (1) normal control (n=5); (2) ischemia 30 min reperfusion 0 h (n=5); (3) ischemia 30 min reperfusion 24 h (n=5); (4) ischemia 30 min reperfusion 48 h (n=5); (5) ischemia 30 min reperfusion 72 h (n=5);(6) ischemia 60 min reperfusion 0 h (n=5);(7) ischemia 60 min reperfusion 24 h (n=5);(8) ischemia 60 min reperfusion 48 h (n=5);(9) ischemia 60 min reperfusion 72 h (n=5). The left renal pedicle of the rat in each group was identified and occluded with a nontraumatic vascular clamp for 30 or 60 min or simply exposed. Right nephrectomy was performed and the left kidney was inspected to ensure reperfusion before closure.2. Animals were reanesthetized and the left kidneys were harvested at serial time points in each group. And then the left kidneys were dissected via a midline of longitudinal section. One section wassnap frozen in liquid nitrogen for assaying the level of GDI la and MPO, the others were fixed with 10% formaldehyde for light microscopy examination. The level of CDlla was measured by labelled streptavidin biotin method (LSAB), and MPO activities were determined by spectrophotometer. At the same time, blood samples were obtained from the cava vein and the renal functions were measured. Results1. The level of CDlla was very low in normal renal tissue, but was increased significantly in those of ischemia only and ischemia reperfusion groups (P<0.01). And those levels in the ischemia 60 min reperfusion group were significantly high in ischemia 30 min reperfusion group (PO.01).2. The activities of MPO were very low in normal renal tissue and ischemia only group, but was increased significantly in those of ischemia reperfusion group (PO.01). And those levels in the ischemia 60 min reperfusion group were significantly high in ischemia 30 min reperfusion group (PO.01).3. The levels of serum creatinine (Cr) and blood urea nitrogen (BUN) were not statistically different between normal controls and ischemia only group, but were increased significantly in those of ischemia reperfusion group (PO.01). And those levels in the ischemia 60 min reperfusion group were significantly high in ischemia 30 min reperfusion group (PO.01).4. Histopathologic change in rat renal tissue: the ischemia only group presented the most prominent histopathologic damage, and the more longer of reperfusion time the more milder of damage. And those changes in the ischemia 60 min reperfusion group were more severe than in ischemia 30 min reperfusion group at the same time point.Conclusions1. The level of GDI la and MPO in rat renal tissue increased significantly during rat renal IRI. LFA-1 mediated leukocyte adherence plays an important role La renal IRI.2. Up-regulation of CDlla in rat renal ERI further elucidates the mechanism of relation between IRI and acute rejection, LFA-1 also plays an important role in AR of renal allograft.3. CD1 la higher expression is associated with ischemia time, and this maybe indicated the mechanism of acute rejection of renal allograft.