GLYCEROLIPIDS, NEUTROPHILS, AND LUNG

该提案试图确定1-0-烷基甘油脂如何 (PAF等)介导细胞功能产生 支气管痉挛和过敏反应。它假定PAF统一行动 通过感受器。为了测试这一点，放射性标记的合成类似物将是 使用。这些类似物刺激细胞的机制与PAF完全一样，但 对广泛存在的降解天然化合物的酶具有抵抗力。 这些无线电标记将用于演示、列举和进一步 鉴定人肺和中性粒细胞中的PAF受体 形态上具有这些受体的肺细胞；以及Track受体 中性粒细胞的运动。这些研究使用了经典的受体结合。 技术加上放射自显影和光电子显微镜相结合。 在相关研究中，PAF诱导的人肺的进一步机制 将探索收缩。内源性介质的释放(例如， 白三烯、血栓烷、组胺等)由这些PAF挑战 将测量组织和选择性介体的影响 将对收缩反应的抑制剂进行评估，以便将 要发挥作用的特定调解人。最后，其他1-0-烷基-甘油脂 将会被评估。许多研究给我们提供了这样的观点，即 中性粒细胞、血小板和肺泡巨噬细胞代谢其储存的 1-0-酰基磷脂(如磷脂酰肌醇等)转化为产品 (例如，磷脂酸等)促进细胞反应和 过敏反应。这些研究没有解释最近的三个发现： 同样的细胞含有相当数量的1-0-烷基甘油脂；某些 1-0-烷基-甘油脂(例如，1-0-烷基磷脂酸酯)大于 生物活性是其1-0-酰基类似物的30倍； 这些细胞的甘油脂在功能上可以分为两部分。 可单独调动的水池。这份提案通过以下方式解释了这些发现 提示1-0-烷基-甘油脂代谢也参与了 调节细胞功能。相应地，它将使用新开发的 脂质分离和放射性标记技术追踪周转和死亡 在上述细胞类型中两种类型甘油脂的新合成；以及， 它将比较产品甘油脂的生物活性 血小板/中性粒细胞聚集和脱颗粒、肺收缩、PAF 受体结合和动物过敏反应。为了做到这一点，它使用了有机 合成、生物分析、各种层析技术(薄层， 高性能，气-液)和质谱学。

This proposal seeks to determine how 1-0-alkyl-glycerolipids (platelet-activating factor (PAF), others) mediate cell function to produce bronchospasm and anaphylaxis. It postulates that PAF uniformly acts through receptors. To test this, radiolabeled, synthetic analogues will be used. These analogues stimulate cells by a mechanism exactly like PAF but are resistent to the widespread enzymes degrading the natural compound. The radiolabels will be used to demonstrate, enumerate, and further characterize PAF receptors in human lung and neutrophils; identify morphologically lung cells with these receptors; and track receptor movements in neutrophils. The studies employ classical receptor-binding techniques plus autoradiography combined with light-electron microscopy. In associated studies, further mechanisms of PAF-induced human lung contraction will be explored. Release of endogenous mediators (e.g., leukotrienes, thromboxanes, histamine, etc.) by these PAF-challenged tissues will be measured and the influences of selective mediator inhibitors on the contractile response will be assessed in order to link specific mediators to function. Finally, other 1-0-alkyl-glycerolipids will be evaluated. Many studies give us the view that stimulated neutrophils, platelets, and alveolar macrophages metabolize their stores of 1-0-acyl-phospholipids (e.g., phosphatidylinositol, etc.) into products (e.g., phosphatidic acids, etc.) that promote cellular responses and anaphylaxis. These studies do not explain three recent findings: these same cells contain appreciable amounts of 1-0-alkyl-glycerolipids; certain 1-0-alkyl-glycerolipids (e.g., 1-0-alkyl-phosphatidates) are greater than 30 times more bioactive than their 1-0-acyl analogues; and the glycerolipids of these cells can be functionally segregated into two separately mobilizable pools. This proposal explains these findings by suggesting that 1-0-alkyl-glycerolipid turnover is also involved in mediating cell function. Accordingly, it will use newly-developed lipid-separating and radiolabeling techniques to trace the turnover and de novo synthesis of both types of glycerolipids in the above cell types; and, it will compare the bioactions of the product glycerolipids in assays of platelet/neutrophil aggregation and degranulation, lung contraction, PAF receptor binding, and anaphylaxis in animals. To do this, it uses organic synthesis, bioassays, various chromatographic techniques (thin layer, high-performance, and gas-liquid) and mass spectroscopy.