Hydrogen Peroxide Modulation of the Superoxide Anion Production by Stimulated Neutrophils

Abstract

Hydrogen peroxide (H₂O₂) pretreatment of human neutrophils results in a suppression of the superoxide anion (O₂) production in response to surface-acting stimulants such as lipopolysaccharide (LPS) and opsonized zymosan. This effect was not observed when phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) or tumor necrosis factor α (TNF α) were used as a stimuli. Since the response to PMA and other stimuli was unimpaired by preincubation with H₂O₂, we assume that the H₂O₂ modulated O₃ production is probably due to alteration of the LPS receptor conformation rather than effecting directly NADPH-oxidase. The balance of rective oxygen species (ROS) produced by neutrophils in the state of sepsis may thus be autoregulated by negative feedback phenomena of locally produced H₂O₂