COX2 Mediated Inflammation of Cerebral Blood Vessels

描述(由申请人提供)：本申请的总体目标 为脑血管张力调节的变化提供新的洞察力 在脑损伤之后。具体地说，拟议的研究将调查 减轻脑小动脉延迟性扩张的机制 在短暂接触急性血管扩张剂缓激肽或花生四烯酸后 酸。在大脑中，缓激肽和花生四烯酸都会产生急性的、可逆的 活性氧物质(最有可能是氢)介导的血管扩张 过氧化氢。在分离的组织和细胞中已经显示出活性氧物种。 为了引起环氧合酶-2(COX-2)的表达，环氧合酶-2是一种可诱导的亚型 环氧合酶。我们假设大脑对缓激肽的短暂暴露 或者花生四烯酸产生延迟的血管扩张，在几个小时后发生。 我们还假设，这种延迟的血管扩张几乎是通过 仅由COX-2表达，其表达被活性氧上调 物种。本申请中提出的研究将使用颅窗 麻醉大鼠模型。颅窗提供了独特的学习能力 大脑循环，在那里它保持完整的脑组织。首字母 研究将对集中度进行系统的探索-和 急性接触铅引起的延迟性扩张的时间依赖性 缓激肽或花生四烯酸。后续研究将使用药理学 拮抗剂确定COX-2和诱导型一氧化氮合酶在血管内皮细胞生长中的作用 血管扩张延迟。免疫组织化学研究将证实该表达 COX-2蛋白的表达，并鉴定表达COX-2的细胞类型 共聚焦显微镜双标记。最后一系列项目将 探讨活性氧在缓激肽和花生四烯酸反应中的作用 酸介导的环氧合酶-2延迟表达。氢的特殊作用 将对过氧化氢以及过氧化氢的能力进行调查 单独诱导延迟的COX-2依赖的扩张。 这些研究将在大脑中引入一个重要的新概念 循环-急性扩张剂，如缓激肽和花生四烯酸可以 导致延迟血管效应背后的基因表达变化。

DESCRIPTION (provided by the applicant): The overall goal of this application is to provide new insight into changes in the regulation of brain vascular tone following brain injury. Specifically, the proposed studies will investigate the mechanisms that subserve the delayed dilatation of brain arterioles that occurs after transient exposure to the acute vasodilators bradykinin or arachidonic acid. In brain, both bradykinin and arachidonic acid produce acute, reversible vasodilatation mediated by reactive oxygen species, most likely hydrogen peroxide. Reactive oxygen species have been shown in isolated tissues and cells to cause expression of cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase. We hypothesize that transient exposure of brain to bradykinin or arachidonic acid produces a delayed vasodilatation that occurs hours later. We also hypothesize that this delayed vasodilatation is mediated almost exclusively by COX-2, whose expression is upregulated by reactive oxygen species. The studies proposed in this application will use a cranial window model in anesthetized rats. Cranial windows offer the unique ability to study the cerebral circulation where it remains integrated brain tissue. Initial studies will undertake a systematic exploration of the concentration- and time-dependence of the delayed dilatation produced by acute exposure to bradykinin or arachidonic acid. Subsequent studies will use pharmacologic antagonists to establish the role of COX-2 and inducible NO-synthase in the delayed vasodilatation. Immunohistochemical studies will verify the expression of COX-2 protein and also identify the cell type expressing COX-2 by use of double labeling with confocal microscopy. The final series of projects will investigate the role of reactive oxygen species in bradykinin- and arachidonic acid-mediated delayed expression of COX-2. The specific role of hydrogen peroxide will be investigated, as well as the ability of hydrogen peroxide alone to induce delayed, COX-2 dependent dilatation. These studies will introduce an important new concept in the cerebral circulation - that acute dilators such as bradykinin and arachidonic acid can cause changes in gene expression that underlie delayed vascular effects.