GLYCEROLIPIDS, NEUTROPHILS, AND LUNG

该提案旨在确定1-O-烷基-甘油酯如何 （血小板活化因子（PAF），其他）介导细胞功能以产生 支气管痉挛和过敏反应。 它假定PAF一致地作用于 通过受体。 为了测试这一点，放射性标记的合成类似物将被 采用 这些类似物通过与PAF完全相同的机制刺激细胞， 对广泛存在的降解天然化合物的酶具有抗性。 放射性标记将用于证明、计数和进一步 表征人肺和中性粒细胞中的PAF受体;鉴定 在形态学上，肺细胞具有这些受体; 中性粒细胞的运动。 这些研究采用经典的受体结合 技术加上放射自显影结合光电子显微镜。 在相关研究中，进一步探讨了PAF诱导人肺 将探索收缩。 内源性介质的释放（例如， 白三烯、血栓烷、组胺等）这些PAF挑战者 组织将被测量，选择性介质的影响 将评估对收缩反应的抑制剂， 特定的调解人发挥作用。 最后，其他1-0-烷基-甘油酯 将被评估。 许多研究表明， 中性粒细胞、血小板和肺泡巨噬细胞代谢它们储存的 1-O-酰基-磷脂（例如，磷脂酰肌醇等）成产品 (e.g.,磷脂酸等）促进细胞反应， 过敏反应 这些研究没有解释最近的三个发现： 相同的细胞含有可观量的1-0-烷基-甘油脂;某些 1-O-烷基-甘油脂（例如，1-0-烷基-磷脂酸酯）大于 比它们的1-0-酰基类似物的生物活性高30倍; 这些细胞的甘油脂可以在功能上分离成两种 可单独调动的资金池。 该提案解释了这些调查结果， 这表明1-O-烷基-甘油脂质周转也涉及 介导细胞功能。 因此，它将使用新开发的 脂质分离和放射性标记技术，以跟踪周转和死亡 在上述细胞类型中重新合成两种类型的甘油脂;以及， 它将比较产品甘油脂的生物作用， 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， 合成、生物测定、各种色谱技术（薄层， 高性能和气-液）和质谱。

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.