GLYCEROLIPIDS, THEIR DERIVATIVES, AND NEUTROPHILS

人多形核中性粒细胞(PMN)的产生和灭活 血小板活化因子，白三烯B4和5- 羟基二十碳四烯酸酯。这些脂质介质通过以下方式刺激细胞 传统的转导途径，即通过与其结合 分别为N蛋白偶联、质膜受体。与.相比 然而，其他类似作用的刺激(例如，多肽激素)， 介体具有完全不同的物理化学性质和体内 毒物。因此，细胞可以处理和响应介体，使用 新的机制。我们的进展支持这一观点，并表明 追随模特。首先，介体绕过细胞表面。 穿透质膜并到达其胞内位置的受体 新陈代谢。它们通过细胞质的途径可能涉及到可溶性 转运蛋白。第二，调解人刺激他们自己的合成 同时抑制彼此的代谢失活。这些影响 促进介质积累和生物作用。同时， 中介体迅速促进中介体的积累和生物作用。 同时，中介者迅速(&lt；15秒)停用其 感受器。这种效应限制了细胞的反应。这两款车型都是 我们将在PMN和HL-60细胞中测试一系列预测。 拟议的实验使用化学、生物化学和酶 制备和测量不同细胞产量的技术 磷脂和花生四烯酸代谢产物.密度梯度技术 分离PMN细胞器；结合实验测定介质受体； 和几种评价介质作用和受体的生物测定法 功能。实验将检验：介体/介体受体 内化和其他运动；调解人的约束和运输 胞浆载体蛋白；介体代谢；亚细胞 酶的位置、底物特性和活性 使中介物失活；最近定义的中介物的生物作用 (例如，烯基乙酰甘油磷乙醇胺)；以及 受体结合它们的配体和它们的专利细胞 调解人-无反应。我们的研究可能会扩展现有的概念 受体、刺激转导和配基处理。此外， 中介者和PMN对于宿主防御至关重要，但也 导致炎症、过敏、支气管痉挛、过敏、 和震惊的反应。因此，这项提议与细胞 生理学、药理学、血液学、肺部疾病、免疫学、 和临床医学。

Human polymorphonuclear neutrophils (PMN) produce and inactivate platelet-activating factor, leukotriene B 4, and 5- hydroxyicosatetraenoate. These lipid mediators stimulate cells by conventional transduction pathways, i.e., by binding to their respective, N-protein coupled, plasma membrane receptors. Compared to other similarly acting stimuli (e.g., peptide hormones), however, the mediators have radically different physiochemical properties and in vivo toxicities. Thus, cells may process and respond to the mediators using novel mechanisms. Our progress supports this notion and suggests the following models. First, the mediators bypass their cell surface receptors to penetrate plasmalemma and reach their intracellular sites of metabolism. Their passage through cytosol may involve soluble transfer proteins. Second, the mediators stimulate their own synthesis while inhibiting each others metabolic inactivation. These effects promote mediator accumulation and bioaction. Concurrently, the mediators rapidly promote mediator accumulation and bioaction. Concurrently, the mediators rapidly (<15 sec) inactivate their receptors. This effect limits the cell's response. The two models make a series of predictions which we will test in PMN and HL-60 cells. Proposed experiments employ chemical, biochemical, and enzymatic techniques to prepare and measure production of diverse cellular phospholipids and arachidonate metabolites; density gradient techniques to isolate PMN organelles; binding assays to measure mediator receptors; and several bioassays to evaluate mediator actions and receptor function. Experiments will examine: mediator/mediator receptor internalization and other movements; binding and transport of mediators by cytosolic carrier proteins; mediator metabolism; subcellular locations, substrate specificities, and activities of enzymes inactivating the mediators; the bioactions of recently defined mediators (e.g., alkenyl acetyl glycerophosphoethanolamine); and function of the receptors as they bind their ligand and their patent cells become mediator-unresponsive. Our studies may expand existing concepts on receptors, stimulus transduction, and ligand processing. Furthermore, the mediators as well as PMN are crucial for host defenses but also contributors to inflammatory, allergic, bronchospastic, anaphylactic, and shock reactions. This proposal, then, is relevant to cellular physiology, pharmacology, hematology, pulmonary diseases, immunology, and clinical medicine.