Correlation between arachidonic acid oxygenation and luminol-induced chemiluminescence in neutrophils: inhibition by diethyldithiocarbamate.
Neutrophils from allergic subjects were hypersensitive to stimulation by low calcium ionophore concentration (0.15 microM), resulting in an increased formation of leukotriene B4 (LTB4), 5S-hydroxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid (5-HETE), and other arachidonic acid metabolites through the 5-lipoxygenase pathway. In parallel, luminol-dependent chemiluminescence was also higher in neutrophils from allergic patients at the basal state and after stimulation by calcium ionophore, revealing an enhancement of radical oxygen species and peroxide production. The activity of glutathione peroxidase, the main enzyme responsible for hydroperoxide reduction, was lowered in these cells. Diethyl-dithiocarbamate (DTC) induced a concentration-dependent decrease in chemiluminescence and arachidonic acid metabolism after neutrophil stimulation. These data show that the elevation of arachidonic acid metabolism in neutrophils from allergic patients is strongly correlated with oxidative status. This elevation may be the consequence of an increased cellular hydroperoxide known to activate 5-lipoxygenase (5-LOX) activity and/or an increased arachidonic acid availability, due either to phospholipase A2 (PLA2) activation or inhibition of arachidonate reesterification into phospholipids. Lowering this oxidative status was associated with a concomitant decrease of this metabolism. Our results suggest that the effect of DTC may be the consequence of an inhibition of peroxyl radical and cellular lipid hydroperoxide production. Thus, DTC may modulate arachidonic acid metabolism in neutrophils by modulating the cellular hydroperoxide level.
Chabannes
B
B
INSERM U352, Laboratoire de Biochimie et Pharmacologie, Institut National des Sciences Appliquees, Villeurbanne, France.
Perraut
C
C
El Habib
R
R
Moliere
P
P
Pacheco
Y
Y
Lagarde
M
M
D000328:Adult; D016718:Arachidonic Acid / Q000378:metabolism*; D004050:Ditiocarb / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood; D007975:Leukotriene B4 / Q000096:biosynthesis*; D008163:Luminescent Measurements; D008165:Luminol; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects
D007975:Leukotriene B4; D016718:Arachidonic Acid; D008165:Luminol; D004050:Ditiocarb