FK506对大鼠缺血再灌注肾TNF-α,p^(38)MAPK蛋白表达的影响

Effect of FK506 on TNF-α,p^(38)MAPK Protein Expression in Renal Ischemia-reperfusion Injury of Rats

【目的】探讨FK506对肾缺血再灌注不同时间TNF-α,p38MAPK蛋白表达的影响。【方法】SD大鼠90只,随机分为三组:假手术(sham)组,缺血再灌注(IR)组,FK506+缺血再灌注(FK506+IR)组。FK506+IR组于缺血前6 h经尾静脉注射FK506(0.3 mg/kg,用生理盐水稀释至0.1 ml);IR组于缺血前6 h经尾静脉注射等量生理盐水;sham组仅开腹、分离肾动脉,不阻断血流。采用HE染色分析肾组织病理损伤程度,免疫组化二步法检测TNF-α,p38MAPK蛋白表达的变化。【结果】TNF-α蛋白以在近端小管上皮细胞表达为著,缺血45 min,再灌注2h有少量表达,再灌注6 h,12 h及24 h呈阳性表达,12 h达高峰,FK506+IR组肾组织TNF-α蛋白水平显著低于IR组(P<0.05)。p38MAPK蛋白主要在远端小管上皮细胞表达,缺血45 min,再灌注2 h有少量表达,再灌注6 h,12 h及24 h呈阳性表达,6 h达高峰,FK506+IR组肾组织p38MAPK蛋白水平显著低于IR组(P<0.01)。HE染色可见IR组肾小管上皮细胞有不同程度的片状坏死灶和炎性细胞浸润,FK506+IR组肾组织损伤明显减轻。【结论】FK506可能通过下调TNF-α,p38MAPK蛋白表达水平,减轻肾缺血再灌注损伤。

[Objective]To investigate the effect of FK506 on TNF-α,p^38 MAPK protein expression at different ischemia-reperfusion points. [Methods]Ninety normal male Sprague-Dawley rats were randomly divided into 3 groups ： sham-operated （sham） group, ischemia-reperfusion （IR） group, FK506 ＋ ischemia-reperfusion （FK506 ＋ IR）group. FK506 ＋ IR group was subjected to ischemia-reperfusion injury with intravenous adminis- tration of FK506（0. 3 mg/kg）6 h before ischemia. IR group with the same injury was followed by saline administration in the same manner. Sham group was subjected to only anesthetization and laparotomy but not to ischemia. Pathomorphological changes of renal ischemia-reperfusion injury were observed by HE stain and two-step immunohistochemical methods were used to detect the changes of expression of TNF-α,p^38 MAPK. [Results]TNF-αmainly expressed in renal proximal convoluted tubules,gradually upregulated with duration of ischemia-reperfusion and peaked at 12 h of reperfusion, but these effects were offset by administration of FK506（ P （0.05）. p^38 MAPK mainly located at distal convoluted tubules, peaked at 6 h of reperfusion and was decreased significantly by injection of FK506 （ P （0. 01）. In IR group local necrosis and inflammatory cell infiltration were found by HE stain , while similar changes were scarcely visible in FK506 ＋ IR group. [Conclusion]Renal ischemia-reperfusion injury can be alleviated by FK506 treatment.