TRANSCELLULAR LEUKOTRIENE BIOSYNTHESIS AND INFLAMMATION

白三烯(LT)是肺部炎症的脂质介质 精神错乱。LTB4刺激循环中的中性粒细胞与 血管内皮细胞，引导它们迁移到炎症部位， 并催化其颗粒成分的释放。它可能会产生 痛觉过敏，骨髓生成，并在某些器官发挥肌力作用。 半胱氨基白三烯(LTC4、LTD4和LTE4)收缩心脏和 促进支气管平滑肌和血管通透性。 白三烯的病理生理作用最好的理解是 它们在即刻超敏反应和哮喘中的作用。在慢性疾病中的角色 与肺部疾病相关的炎症是可能的，但不是 完全理解。主宰细胞过程的错乱 生物合成的关键物质LTA4的积累和处置 在白三烯酶途径中的中间体，在 中性粒细胞介导的肺损伤的发病机制。LTA4水解酶，一个速率- 在这种情况下，该途径中的限制性酶是一个关键的决定因素。 我们最近发现了两种类型的LTA4水解酶抑制：i) 一个不可逆的、基于机制的本构过程 伴随催化的失活II)一种药理过程 涉及贝斯汀或卡托普利的可逆抑制。我们建议 LTA4代谢的选择性调节作为一种新的评价指标 减轻肺部炎症的药理策略。我们也 建议确定LTA4累积对以下各项的影响 当LTA4水解酶被抑制时，中性粒细胞。我们的结果是 调查将对治疗产生直接影响 过敏和炎症性肺部疾病的处理。在四年内 我们计划调查的具体目标： I.抑制LTA4水解酶对肺白三烯的影响 离体肺的形成和肺血管压力。 II.LTA4对5-脂氧合酶活性的调节：5-脂氧合酶的失活 脂氧合酶通过不可逆的‘反馈’抑制。 三、LTA4对底物和缓蚀剂结合的要求 水解酶/氨基肽酶活性部位。 四、亲和层析分离催化活性物质 LTA4水解酶/氨基肽酶的自杀性灭活形式： 白三烯跨细胞生物合成检测方法的建立

Leukotrienes (LT) are lipid mediators of pulmonary inflammatory disorders. LTB4 stimulates adhesion of circulating neutrophils to vascular endothelium, directs their migration to sites of inflammation, and catalyzes the release of their granule constituents. It may produce hyperalgesia, myelopoiesis, and exert myotropic effects in some organs. The cysteinyl leukotrienes (LTC4, LTD4, and LTE4) constrict cardiac and bronchial smooth muscle and promote vascular permeability. Pathophysiology actions of leukotrienes are best understood in terms of their roles in immediate hypersensitivity and asthma. Roles in chronic inflammation associated with pulmonary disorders are likely, but not fully understood. Derangements in the cellular processes which govern the accumulation and disposition of LTA4, the pivotal biosynthetic intermediate in the leukotriene enzymatic pathway, are important in the pathogenesis of neutrophil-mediated lung damage. LTA4 hydrolase, a rate- limiting enzyme in the pathway is a critical determinant in the context. We have recently identified two types of LTA4 hydrolase inhibition: i) a constitutive process involving irreversible, mechanism-based inactivation which accompanies catalysis ii) a pharmacological process involving reversible inhibition by bestatin or captopril. We propose to evaluate selective modulation of LTA4 metabolism as a new pharmacological strategy for alleviating pulmonary inflammation. We also propose to determine what are the consequences of LTA4 accumulation on neutrophils when LTA4 hydrolase is inhibited. The results of our investigations will have direct implications for the therapeutic management of allergy and inflammatory pulmonary disorders. In four specific aims we plan to investigate: I. Effect of LTA4 Hydrolase Inhibition on Pulmonary Leukotriene Formation and Pulmonary Vascular Pressure in Isolated, Perfused Lungs. II. Regulation of 5-Lipoxygenase Activity by LTA4: Inactivation of 5- Lipoxygenase via Irreversible 'Feedback" Inhibition. III. Requirements for Substrate and Inhibitor Binding at the LTA4 Hydrolase/Aminopeptidase Active Site. IV. Affinity Chromatography Separation of Catalytically Active and 'Suicide' Inactivated Forms of LTA4 Hydrolase/Aminopeptidase: Development of an Assay to Detect Transcellular Leukotriene Biosynthesis.