Tempol, a membrane-permeable radical scavenger, reduces oxidant stress-mediated renal dysfunction and injury in the rat
Tempol, a membrane-permeable radical scavenger, reduces oxidant stress-mediated renal dysfunction and injury in the rat
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DOI：
10.1046/j.1523-1755.2000.00212.x
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发表时间：
2000-08-01
影响因子：
19.6
通讯作者：
Thiemermann, C
中科院分区：
文献类型：
--
作者：
Chatterjee, PK;Cuzzocrea, S;Thiemermann, C
背景活性氧（ROS）的产生参与了肾缺血再灌注损伤的发病机制。本研究的目的是研究tempol在（1）肾缺血/再灌注损伤的体内大鼠模型和（2）暴露于过氧化氢（H2 O2）形式的氧化应激的大鼠肾近端小管（PT）细胞的细胞损伤和死亡中的作用。雄性Wistar大鼠双侧肾蒂钳夹45分钟，然后再灌注6小时。在再灌注之前和整个再灌注期间施用Tempol（30 mg/kg/h）、去铁胺（DEF; 40 mg/kg/h）或Tempol（30 mg/kg/h）和DEF（40 mg/kg/h）的组合。尿素的血浆浓度。测定肌酐、钠离子、γ-谷氨酰转移酶（γ GT）、谷草转氨酶（AST）以及尿钠离子和N-乙酰基-β-D-氨基葡萄糖苷酶（NAG），以评估肾功能和再灌注损伤。检测肾脏髓过氧化物酶（MPO）活性和丙二醛（MDA）水平，分别评估多形核细胞（PMN）浸润和脂质过氧化反应。肾切片用于肾损伤的组织学分级和硝基酪氨酸和聚（ADP-核糖）合成酶（PARS）的免疫组织化学定位。将大鼠PT细胞的原代培养物与H2 O2（1 mmol/L）一起孵育4 h，无论是否存在递增浓度的tempol（0.03 - 10 mmol/L）、DEF（0.03 - 10 mmol/L）或tempol（3 mmol/L）或DEF（3 mmol/L）的组合。PT细胞损伤和死亡分别通过评估线粒体呼吸和乳酸脱氢酶（LDH）释放来确定。在体内，tempol显着降低了由肾缺血/再灌注产生的尿素，肌酐，γ GT，AST，NAG和FENa的增加，表明肾功能和损伤的改善。Tempol还显著降低肾脏MPO活性和MDA水平，分别表明PMN浸润和脂质过氧化作用的减少。Tempol减少了与缺血/再灌注相关的肾损伤的组织学证据，并导致硝基酪氨酸和PARS染色的大幅减少，表明亚硝化和氧化应激减少。在体外，tempol显着衰减H2 O2介导的线粒体呼吸减少和LDH释放增加大鼠PT细胞，表明细胞损伤和死亡减少。在体内和体外实验中，Tempol的作用与使用Fe 2+螯合剂DEF的作用相似，但DEF和Tempol联合使用对肾缺血/再灌注损伤或氧化应激介导的PT细胞损伤/死亡没有产生任何额外的有益作用。我们的研究结果表明，膜渗透性自由基清除剂，tempol，减少肾功能障碍和损伤与缺血/再灌注的肾脏。
Background. The generation of reactive oxygen species (ROS) contributes to the pathogenesis of renal ischemia-reperfusion injury. The aim of this study was to investigate the effects of tempol in (1) an in vivo rat model of renal ischemia/ reperfusion injury and on (2) cellular injury and death of rat renal proximal tubular (PT) cells exposed to oxidant stress in the form of hydrogen peroxide (H2O2).Method's. Male Wistar rats underwent bilateral renal pedicle clamping for 45 minutes followed by reperfusion for six hours. Tempol (30 mg/kg/h), desferrioxamine (DEF; 40 mg/kg/h), or a combination of tempol (30 mg/kg/h) and DEF (40 mg/kg/h) were administered prior to and throughout reperfusion. Plasma concentrations of urea. creatinine, Na+, gamma-glutamyl transferase (gamma GT), aspartate aminotransferase (AST), and urinary Na+ and N-acetyl-beta-D-glucosaminidase (NAG) were measured for the assessment of renal function and reperfusion injury. Kidney myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were measured for assessment of polymorphonuclear (PMN) cell infiltration and lipid peroxidation, respectively. Renal sections were used for histologic grading of renal injury and for immunohistochemical localization of nitrotyrosine and poly(ADP-ribose) synthetase (PARS). Primary cultures of rat PT cells were incubated with H2O2 (1 mmol/L for 4 h) either in the absence or presence of increasing concentrations of tempol (0.03 to 10 mmol/L), DEF (0.03 to 10 mmol/L), or a combination of tempol (3 mmol/L) or DEF (3 mmol/L). PT cell injury and death were determined by evaluating mitochondrial respiration and lactate dehydrogenase (LDH) release, respectively.Results. In vivo, tempol significantly reduced the increase in urea, creatinine, gamma GT, AST, NAG, and FENa produced by renal ischemia/reperfusion, suggesting an improvement in both renal function and injury. Tempol also significantly reduced kidney MPO activity and MDA levels, indicating a reduction in PMN infiltration and lipid peroxidation, respectively. Tempol reduced the histologic evidence of renal damage associated with ischemia/reperfusion and caused a substantial reduction in the staining for nitrotyrosine and PARS, suggesting reduced nitrosative and oxidative stress. In vitro, tempol significantly attenuated H2O2-mediated decrease in mitochondrial respiration and increase in LDH release from rat PT cells, indicating a reduction in cell injury and death. Both in vivo and in vitro, the beneficial actions of tempol were similar to those obtained using the Fe2+ chelator DEF. However, coadministration of DEF and tempol did not produce any additional beneficial actions against renal ischemia/reperfusion injury or against oxidative stress-mediated PT cell injury/death.Conclusion. Our results suggest that the membrane-permeable radical scavenger, tempol, reduces the renal dysfunction and injury associated with ischemia/reperfusion of the kidney.