Experimental Studies On Protective Effects Of RPM On Renal Ischemia-Reperfusion Injury In Rats

Objective:To investigate the effect of RPM on renal ischemia-reperfusion injury in rats. To demonstrate the mechanism of RPM on renal ischemia-reperfusion injury, in order to research the effective method to cure the ischemia-reperfusion injury in kidney.Methods:The first part: Acute ischemic renal injury model was established(ectomize right kidney,45 min of left renal ischemia and reperfusion for 24 h).Thirty Male Wistar rats were randomly divided into 3 groups: sham operation group (control group or group C,without renal ischemia),renal ischemia-reperfusion group(ischemia-reperfusion group or group I , without RPM) , RPM and ischemia-reperfusion group(RPM+IR ) (RPM group or group U).BUN level,serum creatinine values and renal uhrastructure were measured.The second part: Acute ischemic renal injury model was established(ectomize right kidney,45 min of left renal ischemia and reperfusion for 0h,24 h,48h,72h).Eighty one normal male Wistar rats were randomly divided into 3 groups:sham-operated group (sham,without renal ischemia),ischemia-reperfusion group(IR, without RPM),RPM and ischemia-reperfusion group(RPM+IR);nine phases. Pathomorphological changes of renal ischemia-reperfusion injury were observed by HE stain,the apoptosis rate in renal tissue was measured by TUNEL method and SABC immunohistochemical methods were used to detect the changes of expression of Fas,bcl-2.Results:The first part: Serum creatinine (168±37)μmol/L and BUN concentration(22±6)mmol/L in group 1 were significantly higher than those in group U : serum creatinine(113±17)μmol/L and BUN concentration(13.8±2.3)mmol/L (P<0.05). the renal uhrastructure was greatly injured in group I,meanwhile,it was obviously ameliorated in group U.The second part: The apoptosis index increased in the kidneys of ischemia-reperfusion group (P< 0.05) but these effects were offset by administration of RPM (P< 0.05).bcl-2 and Fas concentration were significantly higher in IR group than those in sham group(P< 0.05),As compared with ischemia-reperfusion group,bcl-2 expression increased and Fas expression decreased significantly in RPM + IR group(P< 0.05).In IR group local necrosis and inflammatory cell infiltration were found by HE stain.while similar changes were scarcely visible in RPM + IR group.Conclusion:The first part: RPM greatly improved renal function and provides remarkable protection on renal ultrastructure after ischemia-reperfusion of kidney in rats.The second part: The results show that Renal ischemia-reperfusion injury can be alleviated by RPM treatment,and the protective effect of RPM may be RPM has significant effect on the up-regulation of bcl-2 and down-regulation of Fas expression in renal ischemia-reperfusion injury.