Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, México DF, México.
J Neurosci Res. 2010 Feb 15;88(3):620-9. doi: 10.1002/jnr.22240.
Intrastriatal injection of quinolinic acid (QUIN) to rodents reproduces some biochemical, morphological, and behavioral characteristics of Huntington's disease. NAD(P)H oxidase is an enzymatic complex that catalyzes superoxide anion (O(2).(-)) production from O(2) and NADPH. The present study evaluated the role of NAD(P)H oxidase in the striatal damage induced by QUIN (240 nmol/microl) in adult male Wistar rats by means of apocynin (APO; 5 mg/kg i.p.), a specific NAD(P)H oxidase inhibitor. Rats were given APO 30 min before and 1 hr after QUIN injection or only 30 min after QUIN injection. NAD(P)H oxidase activity was measured in striatal homogenates by O2()(-) production. QUIN infusion to rats significantly increased striatal NAD(P)H oxidase activity (2 hr postlesion), whereas APO treatments decreased the QUIN-induced enzyme activity (2 hr postlesion), lipid peroxidation (3 hr postlesion), circling behavior (6 days postlesion), and histological damage (7 days postlesion). The addition of NADH to striatal homogenates increased NAD(P)H oxidase activity in striata from QUIN-treated animals but not from sham rats. Interestingly, O2()(-) production in QUIN-lesioned striata was unaffected by the addition of substrates for intramitochondrial O2()(-) production, xanthine oxidase and nitric oxide synthase, suggesting that NAD(P)H oxidase may be the main source of O2()(-) in QUIN-treated rats. Moreover, the administration of MK-801 to rats as a pretreatment resulted in a complete prevention of the QUIN-induced NAD(P)H activation, suggesting that this toxic event is completely dependent on N-methyl-D-aspartate receptor overactivation. Our results also suggest that NAD(P)H oxidase is involved in the pathogenic events linked to excitotoxic/prooxidant conditions.
纹状体注射喹啉酸（QUIN）可复制亨廷顿病的一些生化、形态和行为特征。NAD（P）H 氧化酶是一种酶复合物，可催化 O2 和 NADPH 产生超氧阴离子（O2(-)）。本研究通过腹腔注射特异性 NAD（P）H 氧化酶抑制剂 apocynin（APO；5 mg/kg），评估 NAD（P）H 氧化酶在 QUIN（240 nmol/μl）诱导的纹状体损伤中的作用。大鼠在 QUIN 注射前 30 分钟和注射后 1 小时给予 APO，或仅在 QUIN 注射后 30 分钟给予 APO。通过 O2(-)产生测量纹状体匀浆中的 NAD（P）H 氧化酶活性。QUIN 输注到大鼠体内可显著增加纹状体 NAD（P）H 氧化酶活性（损伤后 2 小时），而 APO 处理可降低 QUIN 诱导的酶活性（损伤后 2 小时）、脂质过氧化（损伤后 3 小时）、转圈行为（损伤后 6 天）和组织学损伤（损伤后 7 天）。将 NADH 添加到 QUIN 处理动物的纹状体匀浆中增加了 NAD（P）H 氧化酶活性，但对 sham 大鼠的纹状体匀浆无影响。有趣的是，加入线粒体 O2(-)产生的底物（黄嘌呤氧化酶和一氧化氮合酶）后，QUIN 损伤纹状体中的 O2(-)产生不受影响，这表明 NAD（P）H 氧化酶可能是 QUIN 处理大鼠中 O2(-)的主要来源。此外，MK-801 作为预处理给予大鼠可完全预防 QUIN 诱导的 NAD（P）H 激活，表明这种毒性事件完全依赖于 N-甲基-D-天冬氨酸受体过度激活。我们的结果还表明，NAD（P）H 氧化酶参与与兴奋毒性/促氧化剂条件相关的致病事件。
