中文摘要：

目的观察上调肾脏intermedin（IMD）表达对大鼠肾脏缺血再灌注（I／R）的影响。方法24只健康雄性Wistar大鼠随机分为假手术组、肾脏I／R组、IMD＋I／R组、空质粒＋I／R组，每组6只。所有动物于I／R术24h后杀检，取肾组织进行光镜检查，留取血清测定尿素氮（BUN）和血清肌酐（Scr）的浓度。免疫组织化学方法、半定量RT．PCR、Western印迹检测肾组织IMD表达及部位。Western印迹测定内皮素1（ET．1）、肿瘤坏死因子α（TNF．仪）蛋白的表达。结果HE、PAS染色结果显示，I／R组肾小管及间质病理损伤显著重于假手术组，IMD＋I／R组小管间质损伤程度较肾脏I／R模型组及空质粒＋I／R模型组明显减轻（1．5±0．8比7．6±2．3和7．0±1．8，均P〈0．05】。与假手术组[（BUN3．85±0．21mmol／L，Scr（48．67＋3．61）txmol／L相比，I／R组、IMD＋I／R组以及空质粒＋I／R组BUN（10．13±2．14）mmol／L，（7．73±I．03）mmol／L，（9．77a-1．92）mmol／L和Scr（80．33＋7．15）Ixmol／L，（58．50＋3．27）μmol／L，（75．67±7．58）Ixmol／L均明显升高（均P〈0．05），其中IMD＋I／R组较I／R组以及空质粒＋I／R组BUN和Scr水平显著降低（均P〈0．05）。免疫组化结果显示，假手术组IMD呈弱阳性表达，主要位于肾小管间质细胞胞质内，I／R组肾组织IMD在肾小管上皮细胞和间质表达较假手术组上调；IMD＋I／R组肾组织中IMD表达较I／R组明显上调（P〈0．01）。与I／R组及空质粒＋I／R组相比IMD＋I／R组肾组织IMDmRNA，相对含量分别增加了60．7％、66．1％，蛋白相对含量分别增加了51．4％、55．9％。此外，与I／R组相比，IMD＋I／R组肾组织ET．1、TNF-蛋白表达显著降低（ET．1：0．17±0．02比0．08±0．02；TNF-α：0．35±0．02比0．21±0．04，均P〈0．05）。结论在大鼠肾脏I／R前上调IMD表达可能通过抑制ET-1、TNF-α表达

英文摘要：

Objective To investigate the effect of intermedin （IMD） on renal ischemia/ reperfusion （I/R） injury after the up-regulation of IMD. Methods A total of 24 healthy Wistar male rats were randomly divided into four groups, sham-operated group, I/R group, IMD gene transfection ＋I/R group and empty plamid ＋I/R group. All the animals were killed at the end of 24 h of reperfusion. Histological changes and renal function were estimated. The expression and site of IMD were determined by Immunohistochemistry method, semi-quantitative RT-PCR and Western blotting. The protein expressions of endothelin 1 （ET-1）, tumor necrosis factor ot （TNF-tx） weredetected by Western blotting. Results Compared with sham-operated group, tubulointerstitial pathological injury was significant aggravated in I/R group （7.6±2.3） and empty plamid ＋I/R group （7.0±1.8）, and such injury was improved in IMD＋I/R group （1.5±0.8） （P〈0.05）. Compared with I/R group and empty plamid ＋I/R group, the renal dysfunction of IMD ＋I/R group was obviously lessened [BUN：（7.73±1.03） mmol/L vs （10.13±2.14） mmol/L, （9.77±1.92） mmol/L; Scr： （58.50± 3.27） txmol/L vs （80.33±7.15） mmol/L, （75.67±7.58） Ixmol/L, all P〈0.05]. IMD expression was weak in the plasma of tubulointerstitial cells in sham-operated group, and was up-regulated in I/R group. Compared with I/R group, immunohistochemical IMD expression increased obviously （262.03±67.89 vs 175.57±48.06, P〈0.01）. The mRNA expression of IMD in IMD＋I/R group was up-regulated significantly by 60.7% , 66.1% and the protein expression of IMD in IMD＋I/R group increased significantly by 51.4%, 55.9% as compared to I/R and empty plasmid ＋I/R group. Meanwhile, the protein expressions of ET-1 and TNF-ct in IMD＋I/R group were obviously lower compared with those in I/R group （ET-I： 0.08±0.02 vs 0. 17±0.02; TNF-α： 0.21＋0.04 vs 0.35± 0.02, all P〈0.05）. Conclusion IMD gene transfected into kidneys of rats prior to I/R surge