GLYCEROLIPIDS, THEIR DERIVATIVES, AND NEUTROPHILS

人多形核中性粒细胞（PMN）产生并分泌 血小板活化因子、白三烯B 4和5- 羟基二十碳四烯酸。 这些脂质介质刺激细胞， 常规的转导途径，即，通过绑定到他们的 各自的N-蛋白偶联的质膜受体。 相比 其它类似作用的刺激（例如，肽激素），然而， 介质具有完全不同的生理化学性质， 毒性 因此，细胞可以利用细胞内的蛋白质来处理和响应介质。 新机制。 我们的进展支持了这一观点，并表明 以下模型。 首先，介质绕过细胞表面 受体穿透质膜并到达其细胞内位点 新陈代谢的过程。 它们通过胞质溶胶可能涉及可溶性 转移蛋白 第二，中介刺激自身的合成 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， 介质迅速促进介质积累和生物作用。 同时，介质迅速（<15秒）降解其 受体。 这种效应限制了细胞的反应。 这两个模型使 我们将在PMN和HL-60细胞中测试一系列预测。 拟议的实验采用化学，生物化学和酶 制备和测量不同细胞的生产的技术 磷脂和花生四烯酸代谢物;密度梯度技术 分离PMN细胞器;结合试验测定介质受体; 和几种生物测定来评估介质作用和受体 功能 实验将检查：介质/介质受体 内化和其他运动;介质的结合和运输 胞质载体蛋白;介质代谢;亚细胞 酶的位置、底物特异性和活性 灭活介质;最近定义的介质的生物作用 (e.g.,烯基乙酰基甘油磷酸乙醇胺）;和功能的 当它们与配体结合时， 调解员无反应。 我们的研究可能会扩展现有的概念， 受体、刺激转导和配体加工。 此外，委员会认为， 介体和PMN对于宿主防御至关重要， 炎症、过敏、支气管痉挛、过敏性、 和休克反应。 这个建议，然后，是相关的蜂窝 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.