Ingraham L M, Coates T D, Allen J M, Higgins C P, Baehner R L, Boxer L A
Blood. 1982 Jun;59(6):1259-66.
The phospholipid mediator of anaphylaxis, platelet-activating factor (PAF) is chemotactic for polymorphonuclear leukocytes (PMN). We have examined this agent's effects on several other PMN functions. Human PMN were prepared from heparinized venous blood by Ficoll gradient. Metabolic burst was examined by measurement of O2 use and O2.- production in the presence or absence of PAF (10(-6)--10(-9) M). Unless cells were treated with cytochalasin-B (5 micrograms/ml), no significant respiratory burst was demonstrated. However, pretreatment with PAF (10(-7) M) enhanced approximately threefold the O2 utilization found when cells were subsequently stimulated with 10(-7) M FMLP. PAF also stimulated arachidonic acid metabolism in 14C-arachidonic acid-labeled PMN. Thin-layer chromatography analysis of chloroform-methanol extracts showed substances that comigrated with authentic 5-hydroxyeicosatetraenoic acid had a marked increase in radioactivity following PAF stimulation at 10(-7) M. PAF failed to stimulate release of granule enzymes, B-glucuronidase, lysozyme, or myeloperoxidase unless cytochalasin-B were added. PAF from 10(-6) M to 10(-10) M affected PMN surface responses. PMN labeled with the fluorescent dye, chlorotetracycline, showed decreased fluorescence upon addition of PAF, suggesting translocation of membrane-bound cations. Further, the rate of migration of PMN in an electric field was decreased following PAF exposure, a change consistent with reduced cell surface charge. PMN self-aggregation and adherence to endothelial cells were both influenced by PAF (10(-6) M--10(-9) M). Aggregation was markedly stimulated by the compound, and the percent PMN adhering to endothelial cell monolayers increased almost twofold in the presence of 10(-8) M PAF. Thus, PAF promotes a variety of PMN responses: enhances respiratory burst, stimulates arachidonic acid turnover, alters cell membrane cation content and surface charge, and promotes PMN self-aggregation as well as adherence to endothelial cells.
过敏反应的磷脂介质血小板活化因子（PAF）对多形核白细胞（PMN）具有趋化作用。我们研究了该介质对PMN其他几种功能的影响。通过Ficoll梯度从肝素化静脉血中制备人PMN。在存在或不存在PAF（10⁻⁶ - 10⁻⁹ M）的情况下，通过测量氧气消耗和超氧阴离子（O₂⁻）生成来检测代谢爆发。除非细胞用细胞松弛素B（5微克/毫升）处理，否则未显示出明显的呼吸爆发。然而，用PAF（10⁻⁷ M）预处理可使随后用10⁻⁷ M N-甲酰甲硫氨酸-亮氨酸-苯丙氨酸（FMLP）刺激细胞时的氧气利用率提高约三倍。PAF还刺激了用¹⁴C-花生四烯酸标记的PMN中的花生四烯酸代谢。氯仿-甲醇提取物的薄层色谱分析表明，在用10⁻⁷ M PAF刺激后，与 authentic 5-羟基二十碳四烯酸共迁移的物质放射性显著增加。除非添加细胞松弛素B，PAF未能刺激颗粒酶、β-葡萄糖醛酸酶、溶菌酶或髓过氧化物酶的释放。10⁻⁶ M至10⁻¹⁰ M的PAF影响PMN表面反应。用荧光染料氯四环素标记的PMN在加入PAF后荧光降低，表明膜结合阳离子发生易位。此外，PAF暴露后PMN在电场中的迁移速率降低，这一变化与细胞表面电荷减少一致。PAF（10⁻⁶ M - 10⁻⁹ M）对PMN自我聚集和黏附于内皮细胞均有影响。该化合物显著刺激聚集，在存在10⁻⁸ M PAF的情况下，黏附于内皮细胞单层的PMN百分比几乎增加了两倍。因此，PAF促进多种PMN反应：增强呼吸爆发、刺激花生四烯酸周转、改变细胞膜阳离子含量和表面电荷，并促进PMN自我聚集以及黏附于内皮细胞。
