缺血后处理对肾缺血/再灌注损伤后内皮型一氧化氮合酶表达的影响

目的 观察缺血后处理对大鼠急性肾缺血/再灌注损伤的保护作用及缺血后处理对内皮型一氧化氮合酶（eNOS）表达的影响.方法 将2012年9月购自武汉大学动物实验中心的38只8周龄雄性Wistar大鼠依据随机数字表法分为4组：假手术组（8只）、缺血/再灌注组（10只）、缺血后处理组（10只）、缺血预处理组（10只）.建立原位大鼠单侧肾缺血/再灌注动物模型,摘除右肾后对左肾行缺血后处理,10 s再灌注,10 s缺血,6次循环后再灌注24 h.采用全自动生化分析仪检测血尿素氮、肌酐,比色法测定血浆一氧化氮.免疫组织化学法和反转录聚合酶链反应（RT-PCR）检测eNOS表达.蛋白免疫印迹法（Western blot）检测胞质eNOS水平.结果 肾缺血/再灌注24 h后,缺血/再灌注组中血尿素氮、肌酐、一氧化氮较假手术组显著增高（P＜0.05）,组织中eNOS表达较假手术组升高（P＜0.05）,缺血后处理组和缺血预处理组中的血尿素氮、肌酐较缺血/再灌注组降低（P＜0.05）,血清一氧化氮和组织中eNOS较缺血/再灌注组中升高更显著（P＜0.05）.结论 缺血后处理对大鼠肾缺血/再灌注损伤有保护作用,具有临床应用价值.其保护机制可能与缺血后处理诱导eNOS的合成增多有关.

Effects of Ischemic Postconditioning on eNOS Expression in Rats with Renal Ischemia/Reperfusion Injury

Objective To investigate the protective effect of ischemic postconditioning on rats with acute renal ischemia/reperfusion（I/R） injury and its effect on endothelial nitric oxide synthase（eNOS） and nitric oxide（NO）. Methods A rat I/R model was established with 38 male Wistar rats aged 8 weeks purchased from Wuhan University Animal Experiment Center in September 2012, which were divided into 4 groups according to random number table method：sham group （8）, ischemia/reperfusion group （lO） , postcondition- i ng ischemia group （ 10 ） , preconditioning ischemia group （10）. The renal postconditioning was induced by 6 cycles of left renal reperfusion （ 10 s ） and ischemia （ 10 s ） followed by reperfusion （24 h ） after resection of right kidney. The parameters of renal function were determined by auto-biochemical analyzer. The concentra-tions of NO were measured with chromometry,eNOS in cytoplasm was examined by immunohistochemistry, RT-PCR and Western blot. Results After ischemia and reperfusion injury for 24 h,compared with the sham group, BUN, Cr and NO increased significantly in the rats undergoing I/R procedure （ P 〈 0.05 ）. The release of eNOS increased significantly in the rats undergoing L/R procedure compared with the sham group （ P 〈 0.05 ）. After ischemic postcondtioning and ischemie preconditioning, the levels of BUN, Cr were signifi- cantly decreased （ P 〈 0. 05 ）, NO in the serum and the release of eNOS were significantly increased （P 〈0.05）. Conclusion Isehemie postcondtioning can protect the rats subjected to ischemia and reperfu-sion injury and has the value of clinical application. Its protective mechanism may be related to the increase of the release of eNOS induced by ischemie postconditioning.