Arachidonic acid metabolism in human neutrophils: lack of effect of cyclosporine A.
The metabolism of arachidonic acid (AA) in human neutrophils was studied by incorporation of 1-14C-AA, removal of excess 1-14C-AA, and stimulation of radiolabelled cells with A23187. Radiolabelled lipids were quantitated by extraction, thin-layer chromatography, autoradiography, and laser densitometry. Following 5 h of incubation with 1-14C-AA, the maximum amount of radioactivity was located in triglycerides, 70%, and phospholipids, 30%. Activation of the cells with calcium ionophore A23187 led to release of free AA, 58%, whereas AA-metabolites revealed mainly lipoxygenase (arachidonate 5 lipoxygenase, E.C. 1. 13. 11. 34) activity, 5-HETE 13%, LTB4 5%, with only small amounts of cyclooxygenase (prostaglandin synthase, E.C. 1. 14. 99. 1) metabolites, HHT 2%. Intra-assay coefficient of variation for release of metabolites was approximately 15%. A potent immunosuppressive agent, cyclosporine A (CS-A) was shown to be without any effect in AA-release and metabolism. This method is applicable to studies of both basic cell function in human disease and to further immunopharmacological investigations.
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood*; D000001:Calcimycin / Q000494:pharmacology; D002250:Carbon Radioisotopes; D002396:Catechols / Q000494:pharmacology; D003524:Cyclosporins / Q000494:pharmacology*; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D009637:Masoprocol; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000096:biosynthesis / Q000097:blood; D014280:Triglycerides / Q000096:biosynthesis / Q000097:blood
D001095:Arachidonic Acids; D002250:Carbon Radioisotopes; D002396:Catechols; D003524:Cyclosporins; D010743:Phospholipids; D014280:Triglycerides; D016718:Arachidonic Acid; D000001:Calcimycin; D009637:Masoprocol; D007213:Indomethacin