热休克蛋白70对肾脏缺血预处理保护作用的研究

目的 :研究缺血预处理对肾脏缺血再灌注损伤的保护作用 ,观察热休克蛋白 70 (HSP70 )的表达变化并探讨其作用机制。方法 :建立大鼠肾脏缺血再灌注损伤模型并进行缺血预处理 ,实验分组 :假手术组 (S组 )、缺血再灌注组 (IR组 )和缺血预处理组 (PC组 )。各组再灌注后检测血清肌酐 (Scr)、肾组织丙二醛 (MDA)含量 ,肾组织石蜡切片苏木精伊红染色以及免疫组化染色。结果 :PC组Scr值、肾小管病理评分、肾组织中MDA含量明显低于IR组 (P <0 .0 5 ) ,PC组与S组比较差异无显著性意义 (P >0 .0 5 ) ;HSP70免疫组化染色 :S组未见明显的阳性反应产物 ,PC组和IR组肾小管上皮细胞胞质可见棕黄色阳性反应产物。计算机图像分析显示PC组灰度值显著高于IR组 (P <0 .0 1)。结论 :缺血预处理对肾脏缺血再灌注损伤有明显保护作用 ,其作用机制可能与HSP70本身的细胞保护作用及HSP70的细胞内抗氧化作用有关

Study the role of HSP70 in the protective mechanisms of ischemic preconditioning to the kidney

Purpose:To investigate the role of heat shock protein 70 (HSP70) in renal ischemia-reperfusion injury in rats after ischemic preconditioning by examining the change of the expression of HSP70.Methods:Forty five Sprague-Dawley rats were randomly divided into three groups: sham-operation(S) group, renal ischemia-reperfusion(IR) group and ischemic preconditioning(PC) group. The serum creatinine (Scr) and morphologic change and content of malondialdehyde(MDA) of the kidney were assessed. Expression of HSP70 in renal cells was analysed by immunohistochemical technique.Results:In the IR group, the level of Scr in the blood, MDA in the renal tissue and the score of tubules were significantly higher than those of the PC group (P< 0.05). In PC and IR groups, HSP70 positive immunoreactive cells could be detected, but the PC group showed higher expression than that of the IP group (P< 0.05), In the S group, HSP70 positive immunoreactive cells were not found in the renal tubules.Conclusions:Ischemic preconditioning could protect the damage of ischemia- reperfusion to the kidney, and the mechanism may be related to the higher expression of HSP70 which can protect the cells directly and decrease the content of oxygen-derived free radidicals.