Receptor-mediated action of hepoxilin A3 releases diacylglycerol and arachidonic acid from human neutrophils |
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Authors: | S Nigam S Nodes G Cichon E J Corey C R Pace-Asciak |
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Institution: | Department of Gynaecological Endocrinology, Klinikum Steglitz, Free University of Berlin, FRG. |
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Abstract: | We have previously shown that hepoxilin A3 increases the intracellular concentration of Ca+2 in human neutrophils. Herein we address the initial events of hepoxilin action on the neutrophil which precede the rise in intracellular calcium. We show that hepoxilin A3 at 10-1000 nM concentrations releases from 1-14C]-arachidonic acid labeled neutrophils diacylglycerol and unesterified arachidonic acid in a time and concentration dependent fashion. The release of arachidonic acid and diacyglycerol are receptor-mediated events which are blocked by pertussis toxin. This data shows that hepoxilin A3 stimulates phospholipases C and A2 in the cell which may be involved in the rise in cytosolic calcium. Thus, hepoxilins may represent a hitherto unrecognised class of cellular mediators. |
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