Metabolic, membrane, and functional responses of human polymorphonuclear leukocytes to platelet-activating factor

摘要: 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 were prepared from heparinized venous blood by Ficoll gradient. Metabolic burst was measurement O2 use and O2.- production in the presence or absence PAF (10(-6)--10(-9) M). Unless cells treated with cytochalasin-B (5 micrograms/ml), no significant respiratory demonstrated. However, pretreatment (10(-7) M) enhanced approximately threefold utilization found when subsequently stimulated 10(-7) M FMLP. also arachidonic acid metabolism 14C-arachidonic acid- labeled PMN. Thin-layer chromatography analysis chloroform-methanol extracts showed substances that comigrated authentic 5- hydroxyeicosatetraenoic had a marked increase radioactivity following stimulation at M. failed to stimulate release granule enzymes, B-glucuronidase, lysozyme, myeloperoxidase unless added. 10(-6) 10(-10) affected surface responses. fluorescent dye, chlorotetracycline, decreased fluorescence upon addition PAF, suggesting translocation membrane-bound cations. Further, rate migration an electric field exposure, change consistent reduced cell charge. self-aggregation adherence endothelial both influenced (10(-6) M--10(-9) Aggregation markedly compound, percent adhering monolayers increased almost twofold 10(-8) PAF. Thus, promotes variety responses: enhances burst, stimulates turnover, alters membrane cation content charge, self- aggregation as well cells.