LEUKOTRIENES AND SLOW REACTING SUBSTANCE OF ANAPHYLAXIS

白三烯和过敏反应的慢反应物质

• 批准号: 2468194
• 负责人: ROBERT Carl MURPHY
• 金额: $ 28.89万
• 依托单位: NATIONAL JEWISH HEALTH
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-15 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2468194
• 关键词: anaphylaxis; asthma; bronchoconstrictors; chemical structure function; clinical research; eicosanoid metabolism; electrospray ionization mass spectrometry; enzyme activity; enzyme induction /repression; enzyme mechanism; human subject; laboratory rat; leukotrienes; lipoxygenase; liver cells; mass spectrometry; matrix assisted laser desorption ionization; neutrophil; tissue /cell culture; urinalysis

DESCRIPTION: (Adapted from the applicant's abstract). Leukotrienes are lipid mediators derived form arachidonic acid by enzymatic oxidation catalyzed by 5-lipoxygenase (5-LO). Interest in these molecules stems from their potent activities in causing neutrophil chemotaxis (LTB4) and bronchial smooth muscle constriction (LTC4). Fundamental questions remain concerning their biosynthesis and metabolism and these are the focus of the proposed work. This project consists of four major goals. The first goal will be to utilize mass spectrometry (MS) for the structural characterization of the major human urinary metabolites of LTB4. A MS quantitative assay will be developed to asses in vivo biosynthesis and normal entry rate of LTB4 into the circulation. The second goal is to asses LTC4 and LTB4 biosynthesis in asthmatic patients that are intolerant to aspirin by quantitative analysis of urinary metabolites for each eicosanoid. LTB4 biosynthesis involves 5-LO and LTA4 hydrolase that are inactivated through a mechanism based suicide reaction that results in covalent binding of an electrophilic eicosanoid intermediate to the enzyme. LTA4 also binds covalently to human serum albumin, a carrier protein for this triene epoxide. The application's third goal is to utilize electrospray tandem MS and MALDI-TOF MS in order to determine the site of covalent attachment and structure of the protein bound lipid. It is expected that such information will provide insights into the mechanism of suicide inactivation and the importance of specific amino acids to the catalysis event The fourth goal will be to investigate the autocrine and paracrine effects of LTB4 on leukotriene biosynthesis and metabolism. The mechanisms by which extracellular LTB4 can modulate neutrophil LTB4 biosynthesis will be investigated. LTB4 has been suggested to increase LTB4 metabolism through the interaction with the nuclear peroxisomal proliferation activating receptor (PPARalpha) and by this mechanism, limit the proinflammatory properties of LTB4. This putative effect of LTB4 will be investigated in hepatocytes and other cells by analysis of both kinetics and extent of leukotriene metabolism. An understanding of the metabolic events occurring in vivo is essential to an understanding of the role these molecules play in inflammation.

描述：（改编自申请人的摘要）。 白三烯是 通过酶氧化从花生四烯酸衍生的脂质介质 由 5-脂氧合酶 (5-LO) 催化。 对这些分子的兴趣源于 它们在引起中性粒细胞趋化性（LTB4）方面的有效活性和 支气管平滑肌收缩（LTC4）。 基本问题仍然存在 关于它们的生物合成和代谢，这些是研究的重点 拟议的工作。 该项目由四个主要目标组成。 第一个进球 将利用质谱（MS）进行结构分析 LTB4 的主要人类尿液代谢物的表征。 质谱 将开发定量测定法来评估体内生物合成和 LTB4 进入循环的正常进入率。 第二个目标是评估 不耐受的哮喘患者中的 LTC4 和 LTB4 生物合成 通过对每种类二十烷酸的尿液代谢物进行定量分析来获得阿司匹林。 LTB4 生物合成涉及失活的 5-LO 和 LTA4 水解酶 通过基于自杀反应的机制，导致共价结合 酶的亲电子类二十烷酸中间体。 LTA4 也结合 与人血清白蛋白共价，该三烯的载体蛋白 环氧化物。 该应用的第三个目标是利用电喷雾串联 MS 和 MALDI-TOF MS 以确定共价附着位点 蛋白质结合脂质的结构。 预计此类信息 将深入了解自杀失活的机制和 特定氨基酸对催化事件的重要性 第四个目标是研究自分泌和旁分泌效应 LTB4 对白三烯生物合成和代谢的影响。 其机制 细胞外LTB4可以调节中性粒细胞LTB4生物合成 调查了。 LTB4 已被建议通过以下方式增加 LTB4 代谢： 与核过氧化物酶体增殖激活的相互作用 受体（PPARα）并通过这种机制，限制促炎性 LTB4 的特性。 LTB4 的这种假定效应将在 通过分析肝细胞和其他细胞的动力学和程度 白三烯代谢。 了解发生的代谢事件 体内对于了解这些分子在体内所起的作用至关重要 炎。