The Studies Of Podocin Expression And Ulinastain Interventionon Podocyte Injury In Renalischemia-reperfusion Rats

ObjectiveTo investigate the expression of the podocin in podocyte and the mechanism of ulinastain induced renal protection after renal ischemia- reperfusion(I/R) rats.It provides rationale to prevent acute ischemia kidney disease for renal ischemia- reperfusion.MethodsSeventy-eight male SD rats were randomly divided into three groups:(C)control group received sham operation have 36 animals;model group(M) consist of (I) renal ischemia and(I/R) renal ischemia- reperfusion group have 36 animals; (U) ulinastain+I/R group have 6 animals.In M and U groups bilateral kidneys were exposed through midline incision and bilateral renal artery were occluded with atraumatic mini-clamp in 60min and open atraumatic mini-clamp.In control group the kidneys were exposed but their pedicles were not clamped. In ulinastatin group ulinastatin 10000U was given i.v. 30min before ischemia and at the beginning of reperfusion. Renel tissue samples were respectively collected at 0,30,60min,3,12h,and 24h of reperfusion in C and M groups and were collected at 60min in ulinastain+I/R group. The distribution of podocin was examined by transmission electron microscope at C,I,I/R60min,24h and U groups . Protein expression and mRNA expression of podocin were examined by immunohistochemistry and semiquantitative reverse transcription PCR respectively.Results1. In I group,the foot processs is lightly damage. The foot processes broadened,the diffuse fusion and effacement of foot processes,even depart, were observed in I/R60min group; The form of podocyte almost recovery in I/R24h group.The foot processes was no significant change in ulinastain+I/R group .2. Podocin staining shows a coarse linearlike pattern along the capillary loops of glomerulus in group (C);it became a coarse linearlike and coarse granular pattern in I and I/R30min; In I/R60min and 3h groups,they show a discontiuous micro linearlike pattern and a micro linearlike pattern in ulinastain+I/R group .In 12h group,it shows coarse granular pattern and coarse and micro linearlike pattern alternate in 24 group.3. In I/R30,60min and 3h groups,podocin mRNA expression was up regulated (p<0.05); In contrast with I group, podocin mRNA expression was up regulated (p<0.05) in I/R30 and I/R60min groups;There was no significant diference in podocin mRNA expression between group C and U. ConclusionThere were severe podocyte damage afte renal ischemia- reperfusion. The expression of podocin protein correlated with podocyte morphosis in renal ischemia- reperfusion .But there no coincidence between the expression of podocin mRNA and podocin protein. It suggest that podocyte switch on it own compensation reaction mechanism. Ulinastain provides remarkable protection on renal podocytes after ischemia-reperfusion of kidney in rats.