BACKGROUND Generation of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) may contribute to renal ischemia/reperfusion (I/R) injury. The aim of this study was to investigate the effects of GW274150, a novel, highly selective, potent and long-acting inhibitor of iNOS activity in rat and mouse models of renal I/R. METHODS Rats were administered GW274150 (5 mg/kg intravenous bolus administered 30 minutes prior to I/R) and subjected to bilateral renal ischemia (45 minutes) followed by reperfusion (6 hours). Serum and urinary indicators of renal dysfunction, tubular and reperfusion injury were measured, specifically, serum urea, creatinine, aspartate aminotransferase (AST) and N-acetyl-beta-d-glucosaminidase (NAG) enzymuria. In addition, renal sections were used for histologic scoring of renal injury and for immunologic evidence of nitrotyrosine formation and poly [adenosine diphosphate (ADP)-ribose] (PAR). Nitrate levels were measured in rat plasma using the Griess assay. Mice (wild-type, administered 5 mg/kg GW274150, and iNOS-/-) were subjected to bilateral renal ischemia (30 minutes) followed by reperfusion (24 hours) after which renal dysfunction (serum urea, creatinine), renal myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were measured. RESULTS GW274150, administered prior to I/R, significantly reduced serum urea, serum creatinine, AST, and NAG indicating reduction of renal dysfunction and injury caused by I/R. GW274150 reduced histologic evidence of tubular injury and markedly reduced immunohistochemical evidence of nitrotyrosine and PAR formation, indicating reduced peroxynitrite formation and poly (ADP-ribose) polymerase (PARP) activation, respectively. GW274150 abolished the rise in the plasma levels of nitrate (indicating reduced NO production). GW274150 also reduced the renal dysfunction in wild-type mice to levels similar to that observed in iNOS-/- mice subjected to I/R. Renal MPO activity and MDA levels were significantly reduced in wild-type mice administered GW274150 and iNOS-/- mice subjected to renal I/R, indicating reduced polymorphonuclear leukocyte (PMN) infiltration and lipid peroxidation. CONCLUSIONS These results suggest that (1). an enhanced formation of NO by iNOS contributes to the pathophysiology of renal I/R injury and (2). GW274150 reduces I/R injury of the kidney. We propose that selective inhibitors of iNOS activity may be useful against renal dysfunction and injury associated with I/R of the kidney.

中文翻译：

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GW274150是一种有效且高度选择性的iNOS抑制剂，可减少实验性肾脏缺血/再灌注损伤。

背景技术诱导型一氧化氮合酶（iNOS）产生一氧化氮（NO）可能有助于肾脏缺血/再灌注（I / R）损伤。这项研究的目的是研究GW274150，一种新型，高度选择性，有效和长效的iNOS活性抑制剂在肾I / R大鼠和小鼠模型中的作用。方法大鼠给予GW274150（I / R前30分钟静脉推注5 mg / kg），并进行双侧肾缺血（45分钟），然后再灌注（6小时）。测量了肾功能不全，肾小管和再灌注损伤的血清和尿液指标，尤其是血清尿素，肌酐，天冬氨酸转氨酶（AST）和N-乙酰基-β-d-氨基葡萄糖苷酶（NAG）酶。此外，肾脏切片用于肾脏损伤的组织学评分，并用于硝基酪氨酸形成和聚[二磷酸腺苷（ADP）-核糖]（PAR）的免疫学证据。使用Griess测定法测量大鼠血浆中的硝酸盐水平。对小鼠（野生型，给予5 mg / kg GW274150和iNOS-/-）进行双侧肾缺血（30分钟），然后再灌注（24小时），然后肾功能不全（血清尿素，肌酐），肾髓过氧化物酶（测量了MPO活性和丙二醛（MDA）水平。结果GW274150在I / R之前给药，可显着降低血清尿素，血清肌酐，AST和NAG，表明I / R引起的肾功能不全和损伤减少。GW274150减少了肾小管损伤的组织学证据，并显着减少了硝基酪氨酸和PAR形成的免疫组织化学证据，分别表明过氧亚硝酸盐形成减少和聚（ADP-核糖）聚合酶（PARP）活化。GW274150消除了血浆硝酸盐水平的上升（表明NO生成减少）。GW274150还可以将野生型小鼠的肾功能不全降低到与接受I / R的iNOS-/-小鼠相似的水平。施用GW274150的野生型小鼠和接受肾脏I / R的iNOS-/-小鼠的肾MPO活性和MDA水平显着降低，表明多形核白细胞（PMN）浸润和脂质过氧化减少。结论这些结果表明（1）。iNOS增强NO的形成有助于肾脏I / R损伤的病理生理学和（2）。GW274150减少了肾脏的I / R损伤。