Protective effect of rhizoma dioscoreae in rats with renal ischemia-reperfusion injury

Objective To investigate the renal protective effect of rhizoma dioscoreae pretreatment in rats with renal ischemia-reperfusion injury.Methods Sixty SD rats(3～4 weeks old) were randomly assigned into normal control(group A,n=6),sham operated control(group B,n=6),intra-gastric pretreatment of Rhizoma Dioscoreae(group C,n=24),and placebo aseptic normal saline lavage pretreatment(group D,n=24).The rats in group C and D were pretreated with rhiizoma dioscoreae and placebo,respectively,for five days before being subjected to bilateral renal vascular occlusion for 45minutes.Six rats of each group were randomly euthanized for blood sampling and kidney harvesting at 2,12,24 and 48h after reperfusion.The blood urea nitrogen(BUN) and serum creatinine(SCr) were measured with automatic biochemistry analyzer.The serum content of malondialdehyde(MDA) was determined with TBA methods.Renal morphologic changes were studied on hematoxylin and eosin(HE) stained sections.Renal tubular cell apoptosis was detected with TUNEL method.PCNA positive renal tubular cells were detected immunohistochemically as proliferation index.Progenitor cells were identified as BrdU and Pax-2 double labeling cell and localized in the kidney by confocal microscopy.Results Scr,BUN and MDA levels in group C were significantly lower than those in group D at 12,24 and 48h after reperfusion.The tubular cell apoptosis was detected in the kidney at 2h after ischemia-reperfusion injury and reached the highest level at 12h.Renal apoptosis score in group C was much less than that in group D.There were more PCNA positive tubular cells in group C than those in group D,and BrdU and Pax-2 double labeling cells were localized in the renal tubules after ischemia-reperfusion injury.Conclusions Renal ischemia-reperfusion injury may result in significant histological damage and renal dysfunction.Rhizoma dioscoreae lavage pretreatment in rats results in the attenuation of oxidative damage and apoptosis,and enhancement of renal tubular cell proliferation.BrdU and Pax-2 double labeling cells were identified as progenitor cells participating in renal repair after ischemia-reperfusion injury.