Kinetics of 5-lipoxygenase activation, arachidonic acid release, and leukotriene synthesis in human neutrophils: effects of granulocyte-macrophage colony-stimulating factor.
The kinetics of 5-lipoxygenase (5-LO) activation in human neutrophils was compared with that of arachidonic acid (AA) release and leukotriene (LT) B4 synthesis, and the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on these processes was examined. The soluble agonists N-formyl-Met-Leu-Phe and platelet-activating factor stimulated 5-LO activity, which peaked within 10 s and then rapidly declined. At all time points investigated, 5-LO activity was greater in GM-CSF-treated neutrophils. The release of AA was detectable only in GM-CSF-treated neutrophils and peaked 1 min after the agonist stimulation. Accordingly, synthesis of LTB4 was detected only in GM-CSF-treated neutrophils. By comparison, 100 nM of ionomycin induced a greater and sustained activation of 5-LO, resulting in a greater synthesis of LTB4. These results show that 5-LO activation is immediate and transient in response to soluble agonists and that temporal dissociation with the release of AA limits LTB4 synthesis.
Krump
E
E
Centre de Recherche en Inflammation, Immunologie et Rhumatologie, Centre de Recherche du CHUL, Québec, Canada.
Borgeat
P
P
D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism*; D016718:Arachidonic Acid / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D015759:Ionomycin / Q000494:pharmacology; D007700:Kinetics; D015289:Leukotrienes / Q000096:biosynthesis*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology; D013997:Time Factors
D015289:Leukotrienes; D010972:Platelet Activating Factor; D016718:Arachidonic Acid; D015759:Ionomycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D001094:Arachidonate 5-Lipoxygenase