A possible requirement for arachidonic acid lipoxygenation in the mechanism of phagocytic degranulation by human neutrophils stimulated with aggregated immunoglobulin G.
Aggregated immunoglobulin G (AggIgG) caused a concentration-dependent extracellular release of granule-associated lysozyme and myeloperoxidase (MPO) from human neutrophils. Generation of the 5-lipoxygenase product of arachidonic acid (AA) metabolism, 5(S),12(R)-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid [leukotriene B4 (LTB4)], by neutrophils is exposed to AggIgG occurred in the presence but not absence of exogenous AA. U-60,257B (piriprost potassium), an inhibitor of leukotriene synthesis, caused a dose-related suppression of LTB4 production and granule exocytosis by AggIgG-treated cells. These data suggest that a lipoxygenase product of AA metabolism may mediate AggIgG-induced phagocytic release of granule constituents from neutrophils.
D001091:Arachidonate Lipoxygenases; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000494:pharmacology / Q000031:analogs & derivatives; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism; D009113:Muramidase / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology*; D009195:Peroxidase / Q000378:metabolism; D010587:Phagocytosis
D001095:Arachidonic Acids; D007074:Immunoglobulin G; D007975:Leukotriene B4; D016718:Arachidonic Acid; D011464:Epoprostenol; D009195:Peroxidase; D001091:Arachidonate Lipoxygenases; D008084:Lipoxygenase; D009113:Muramidase; C035296:piriprost