DIHOMO-Y-LINOLENIC ACID METABOLITES LIPOXYGENASE PATHWAY

花生四烯酸是合成花生四烯酸的主要脂肪酸前体 具有生物活性的二十烷类化合物。二十烷类化合物的关键作用是 生理和免疫机制的调节机制有很好的文献记载， 因此，控制它们的水平在治疗中具有重要意义。 许多疾病的预防措施。其中一个很有希望的策略是 上下文是通过提供替代的方式来调节二十烷类化合物的生产 通过饮食控制进行氧化代谢的底物。 最近，人们的注意力集中在双高-伽马的代谢上。 亚麻酸(DHGLA)，因为它被认为是 报春花油在治疗黄斑狼疮方面的明显疗效 各种疾病。这些包括炎症过程、皮肤病、 免疫紊乱、经前疼痛和恶性肿瘤。 拟议研究的总体目标是了解 DHGLA有益营养作用的潜在机制。这个 研究的前提是膜花生四烯酸取代 DHGLA酸化对花生四烯酸衍生产物的衰减作用 二十烷类激素水平。需要检验的总体假设是DHGLA起作用 作为氧化酶的竞争性抑制剂 花生四烯酸底物，DHGLA的氧化产物是 在生物上不如花生四烯酸代谢物，而且在 在某些情况下，前一种化合物作为细胞的拮抗剂。 二十烷类化合物的受体。拟议项目的中心目标将是 生产和鉴定从DHGLA中衍生的代谢物 5-脂氧合酶途径并检测其相对生物活性 免疫和生理功能分析中已知的分子 受花生四烯酸的脂氧合酶产物调节。 这一假说将通过一些体外实验来解决， 其具体目标如下：1)合成和表征 DHGLA的一次和二次氧化产物的催化性能 电泳法纯化的5-脂氧合酶，其主要焦点将是 关于代谢产物的立体化学分析以及 提纯足以测试其生物活性的数量； 2)花生四烯酸竞争的系统动力学分析 (及其代谢物)和DHGLA(及其代谢物)作为底物 白三烯合成的关键酶，在本例中为5-脂氧合酶，LTA 水解酶和LTC合酶；3)生物相关性的测定 使用一组生理和免疫的DHGLA衍生代谢物 已知受脂氧合酶产物调控的检测 花生四烯酸，以及4)阐明 胞嘧啶和二十烷酸类化合物介导的免疫机制。我们的远程 目的是确定在体内观察到的影响的相关性 体外实验。

Arachidonic acid is the major fatty acid precursor for the synthesis of biologically active eicosanoids. The critical role of the eicosanoids as regulators of physiologic and immune mechanisms is well documented and, therefore, control of their levels is of great interest in the treatment of prophylaxis of many diseases. One of the promising strategies in this context is the modulation of eicosanoid production by providing alternate substrates for oxidative metabolism through dietary manipulations. Recently attention has been focused on the metabolism of dihomo-gamma- linolenic acid (DHGLA) because it is thought to be the agent responsible for the apparent effectiveness of primrose oil in the treatment of a variety of diseases. These include inflammatory processes, skin diseases, immunological disorders, premenstrual pain, and malignancy. The overall objective of the proposed research is to understand the basic mechanisms underlying the beneficial nutritional effects of DHGLA. The research is based on the premise that substitution of membrane arachidonic acid by DHGLA results in an attenuation of arachidonic acid-derived eicosanoid levels. The overall hypothesis to be tested is that DHGLA acts as a competitive inhibitor of oxidative enzymes with respect to arachidonic acid substrate, that the oxidation products of DHGLA are biologically less potent than arachidonic acid metabolites, and that in some cases the former compounds act as antagonists to the cellular receptors of eicosanoids. The central goal of the proposed project will be to produce and characterize the metabolites derived from DHGLA via the 5-lipoxygenase pathway and to test the relative bioactivities of these molecules in assays of immune and physiologic functions which are known to be regulated by the lipoxygenase products of arachidonic acid. The hypothesis will be addressed by a number of in vitro experiments, the specific aims of which are as follows: 1) synthesis and characterization of primary and secondary oxygenation products of DHGLA catalyzed by electrophoretically pure 5-lipoxygenase, the main focus of which will be on stereochemical analysis of the metabolites produced as well as purification of quantities sufficient to test their biological activities; 2) systematic kinetic analysis of the competition between arachidonic acid (and its metabolites) and DHGLA (and its metabolites) as substrates for key enzymes of leukotriene synthesis, in this case 5-lipoxygenase, LTA hydrolase, and LTC synthase; 3) determination of the biological relevance of DHGLA-derived metabolites using a battery of physiological and immune assays which are known to be regulated by the lipoxygenase products of arachidonic acid, and 4) elucidation of the interrelationship between cytosine and eicosanoid-mediated immune mechanisms. Our long-range objective is to determine the in vivo relevance of the effects observed in the in vitro experimentation.