【作者】 刘婷；

【导师】 武明虎；

【作者基本信息】 山西医科大学 ， 肾脏病学， 2008， 硕士

【摘要】 目的:探讨去铁胺(DFO)对缺血性急性肾衰竭(iARF)大鼠的保护作用及其作用机制,为DFO更好地应用于临床iARF提供实验性理论依据。方法:1、iARF大鼠模型的制备用钳夹大鼠双侧肾蒂45min的方法制成iARF动物模型。2、雄性Wistar大鼠,随机分成3组:假手术组、手术组、DFO+手术组,每组各12只。手术组:用无损伤动脉夹钳夹大鼠双侧肾蒂45min,然后松开动脉夹,实行再灌注。肉眼见肾脏由暗红变为鲜红,表明再灌注成功(实验过程中动物体温维持在37℃左右),关闭腹腔后继续饲养,缺血前24小时给予等体积生理盐水腹腔注射。假手术组同法打开腹腔并找到肾蒂,但不夹闭肾蒂,后关闭腹腔,打开腹腔前24h给予等体积生理盐水腹腔注射。DFO+手术组:缺血前24小时给予DFO (200mg/kg)腹腔注射,其余处理同手术组。于缺血再灌注24h后检测血尿素氮(BUN)、肌酐(Scr)、超氧化物岐化酶(SOD)、丙二醛(MDA)的含量以及进行肾组织光镜形态学观察和采用免疫组织化学法测定低氧诱导因子-1α(HIF-1α)及血红素加氧酶-1(HO-1)蛋白的表达水平。结果:1、肾组织形态学改变大体:假手术组为正常肾组织;手术组肾脏外形肿大,剖面见皮质肿胀,色苍白,髓质呈暗红色;DFO干预组肾脏外观与正常接近。HE染色:假手术组肾小球、肾小管结构大致正常;手术组肾小管上皮细胞均有不同程度的坏死,间质水肿,大量炎细胞浸润,血管渗透性增加,红细胞溢出;DFO干预组病理改变明显减轻,仅肾小管上皮轻度肿胀。2、手术组大鼠于缺血再灌注后24h的BUN、Scr值显著高于假手术组(P﹤0.01),但DFO+手术组与手术组比,BUN、Scr值却明显降低(P<0.01)。3、手术组大鼠肾组织MDA含量显著高于假手术组(P﹤0.01),但DFO+手术组MDA含量与手术组比却明显降低(P<0.01)。手术组大鼠肾组织SOD活力显著低于假手术组(P﹤0. 01),但DFO+手术组SOD活力明显高于手术组(P﹤0.01)。4、HIF-1α阳性表达为肾小管上皮细胞胞核及部分胞浆内出现棕黄色颗粒,HO-1阳性表达为细胞胞浆出现棕黄色颗粒。假手术组未见阳性细胞,手术组、DFO+手术组显示HIF-1α、HO-1有不同程度的阳性表达,手术组大鼠肾小管上皮细胞HIF-1α、HO-1的阳性表达呈弱阳性,但DFO+手术组HIF-1α、HO-1的表达呈强阳性,各组均未发现肾小球及间质细胞染色阳性。图像分析表明:手术组、DFO+手术组大鼠肾小管上皮细胞HIF-1α、HO-1灰度值水平明显低于假手术组(P﹤0.01),DFO+手术组与手术组比灰度值明显降低(P均﹤0.01)。结论:1、DFO预处理能显著减轻iARF大鼠肾功能损害程度,在病理上明显减轻肾小管损伤程度。2、DFO预处理可通过自由基清除和诱导HIF-1α及下游基因HO-1过表达从而对iARF大鼠发挥保护作用。更多还原

【Abstract】 Objective: To explore the protective effects and mechanism of deferoxamine (DFO) in ischemic acute renal failure(iARF) rats and provide experimental theory basis for the DFO’s clinical application of iARF .Methods:1、Establishment of iARF rat model. Bilateral clipping of renal arteries for 45min.2、Thirty-six male Wistar rats were randomly and averagely divided into three groups : sham、surgery and DFO+ surgery groups. In surgery group,ischemic acute renal failure model was established by bilateral clipping of renal arteries for 45min and reperfusion for 24 hours.Observe the color of renal when it from dark red into bright red that means reperfusion success(the temperature of experimental animals maintained at around 37℃in this process), keeping after close abdominal cavity, and injected the rat with the same size saline throuh intraperitoneal 24 hours before the modle was established. In group sham, find renal arteries but not clip,,the other protocals were same as group model. In group DFO+ surgery,DFO was intraperitoneal injected (200mg/kg) to rats 24h before 45 min renal ischemia,the other protocals were same as group model. Activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA), blood urea nitrogen (BUN),serum creatinine (Scr) were examined.Structure of the kidney was observed under optical microscope.The expression of HIF-1α、HO-1 was detected by immunohistochemistry .Results:1、Morphological changes of renal tissue general: In Sham group renal tissue was normal; in surgery group, the appearance of kidney was saw enlargement section ,cortical swelling,pale color, medulla was dark red; the appearance of kidney was almost normal in DFO + surgery group. Histopathological changes(HE): Normal morphology was observed by optical microscopy in group sham. Red blood cells in glomerulus were seen and swelling cells of renal tubules appeared without inflammatory cell infiltrated and necrosis foci in group surgery. Only red blood cells in glomerulus were seen in group DFO + surgery group.2、Twenty- four hour after reperfusion,the levels of BUN and Scr were significantly higher in the surgery group than in the sham group(P﹤0.01),but the levels of BUN and Scr were marked downturn in the DFO + surgey group than in the surgery3、Twenty- four hour after reperfusion,the content of MDA were significantly higher in the surgery group than in the sham group,but the content of MDA were marked downturn in the DFO + surgey group than in the surgery(P﹤0.01).SOD just the opposite(P<0.01).4、Immunohistochemical study showed that the levels of HIF-1αwas positive expression in the nuclear and in the plasma ,and the levels of HO-1 was positive expression in the plasma and surface of cava of renal tubule cells. There is no positive staining in group sham.Tubule cells expressed low levels of HIF-1α、HO-1 protein in group surgery,the highest levels of HIF-1α、HO-1 were detected in group DFO+ surgery.Glomerulus and interstitial cells were not staind. Image analysis showed that difference between the two groups was significant (P<0.01).Conclusion:1、DFO pretreatment can significantly reduce the injury of renal function and the pathological extent of renal tubular injury in iARF rats.2、DFO pretreatment can protect iARF rats by clearing the free radical and inducing the over-expression of hypoxia factor-1αand hemeoxygenase-1.更多还原