Effects Of Hyperbaric Oxygen On The Expression Of Calpain And CPLA₂ In Ischemia Reperfusion Renal Tissues After Renal Transplantation In Rat

Objective:A renal transplantation model was established for ischemia reperfusion injury?IRI?for the same type of rats.Expression of cytosolic phospholipase A2?cPLA₂?and calpain in endoplasmic reticulum pathway during apoptosis and mitogen-activated protein kinase?MAPK?pathway of rat transplanted kidney was detected;The effects of hyperbaric oxygenation?HBO?on Calpain and cPLA₂ expression were observed.The role of endoplasmic reticulum pathway and MAPK pathway in the pathogenesis of renal IRI and the effect of HBO in the treatment of this pathway were discussed.Method:The paraffin specimens of the same SPF male SD to SD rat kidney transplantation model established previously were used,and were subdivided into sham surgery group,kidney transplantation group and kidney transplantation+HBO treatment group?HBO treatment group?.Each group was divided into 3 groups at 1h,3h and 5h after transplantation.In the sham surgery group,right nephrectomy was performed and the abdominal cavity was closed.Kidney transplantation group:allograft kidney transplantation was performed.HBO treatment group:after kidney transplantation,animals were placed in hyperbaric oxygen chamber for 1h at 0h,2h and 4h,respectively.Transplantation group and HBO treatment group were respectively resected at 1h,3h and5h after surgery,and the transplanted kidney specimens were retained.At the same time,the left kidney was excised in the sham suregery group,the left kidney tissue was retained,and the rats were sacrificed.Paraffin tissue blocks prepared from tissue samples were sliced.Histopathological changes were observed by hematoxylin-eosin?HE?staining.Immunohistochemistry?IHC?was used to detect calpain and cPLA₂ expression in tissues.Result:1.HE staining changes of renal tissue:In the sham surgery group,the renal tissue morphology was normal,and there was no significant difference in tissue structure at each time point.In the kidney transplantation group,interstitial vasodilation,mesangial cell proliferation and glomerular volume enlargement,renal tubule lumen dilation and its epithelial cell swelling were observed;With the extension of reperfusion time,neutrophil infiltration appeared in some glomeruli.Albumen and erythrocyte tubules gradually appeared in the lumen of tubules.The epithelium of the tubule was granular and the tissue damage was severe.HBO treatment group:at 1h and 3h,the degree of renal tissue lesion was less different from that of the kidney transplantation group.At 5h,compared with the kidney transplantation group,it was found that neutrophil infiltration,granular changes,protein tubule type and erythrocyte tubule type were significantly reduced,and tissue damage was reduced.2.Expression changes of calpain and cPLA₂ in renal tissue:Expression of calpain and cPLA₂ was detected by immunohistochemistry.Calpain and cPLA₂ were both expressed in the cytoplasm of renal tubular epithelial cells,while no significant expression was observed in glomerular cells.Relative quantitative analysis showed that:in the sham surgery group,there was no significant difference in the expression level between the two groups at each time point?P>0.05?.With the extension of reperfusion time,the expression of both in the kidney transplantation group and HBO treatment group showed a significantly increased trend?P<0.05?,and was significantly higher than that in the sham surgery group?P<0.05?.However,the expression level of both in the HBO treatment group was significantly lower than that in the kidney transplantation group at each time point?P<0.05?.Conclusion:1.Tissue damage occurred early after kidney transplantation;After reperfusion,the expression levels of calpain and cPLA₂ protein in the transplanted renal tissue were significantly increased,which became more obvious with the prolongation of reperfusion time.2.HBO treatment significantly inhibited calpain and cPLA₂ expression in renal IRI tissue;...