Neutrophil chemotaxis, phagocytosis, and generation of reaction oxygen species show a hierarchy of responsiveness to increasing concentrations of N-formyl-Met-Leu-Phe.
We assessed the effect of varying concentrations of N-formyl-methionyl-leucyl-phenylalanine (fMLP) on neutrophil chemotaxis, phagocytosis, and reactive oxygen species generation. Boyden chamber chemotaxis was first elicited at an fMLP concentration of 10(-11) M, reached a peak at 10(-10) M, and declined at higher concentrations. Phagocytosis was first activated at 10(-10) M, reached its highest level at 10(-9) M, and declined at higher concentrations. O2-, H2O2 and OH. generation were elicited to a significant degree only at a fMLP concentration of 10(-8) M, or higher, reaching a peak at 10(-6) M. Thus, a distinct hierarchy was observed in the order of activation of these three neutrophil functions to varying concentrations of a soluble agonist. A teleologic model of neutrophil function that accounts for these observations is proposed.
Iizawa
O
O
Department of Dermatology, Tohoku University School of Medicine, Sendai, Japan.
Akamatsu
H
H
Niwa
Y
Y
D000293:Adolescent; D000328:Adult; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D009240:N-Formylmethionine Leucyl-Phenylalanine