Regulation of neutrophil activation by oleic acid.
Physiological concentrations of oleic acid inhibited C5a-induced myeloperoxidase release from neutrophils. The inhibition occurred promptly following the addition of oleic acid, was dose-dependent and saturable, and was greater at low concentrations of C5a. Kinetic analysis of the curve for 1/myeloperoxidase release against 1/[C5a] in the presence of oleic acid, was compatible with a cooperative pattern of interaction. The inhibitory effect persisted after repeated washings of cells preincubated with oleic acid. The effect of oleic acid was not specific for C5a-induced neutrophil activation; oleic acid also inhibited myeloperoxidase release induced by the Ca2+ ionophore A-23187, as well as zymosan activated serum-induced chemotaxis. In experiments designed to localize the site of action of oleic acid on neutrophil activation, an intracellular oleic acid-binding protein M(r) = 13,000) was isolated. The results suggest that acute changes in plasma fatty acid levels may have significant effects on neutrophil function under physiological conditions.
Higazi A al-R
Department of Clinical Biochemistry, Hadassah Medical Center, Jerusalem, Israel.
Barghouti
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D015936:Complement C5a / Q000494:pharmacology; D006801:Humans; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism
D009829:Oleic Acids; D019301:Oleic Acid; D015936:Complement C5a; D009195:Peroxidase