Differential effects of platelet-activating factor on superoxide anion production in human eosinophils and neutrophils

Abstract

The effect of platelet-activating factor (PAF) on the generation of superoxide anion (O2-) in human eosinophils and neutrophils was examined. The presence of PAF potentiated O2- production in either opsonized zymosan- or formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated cells. The effect of PAF was prominent in opsonized zymosan-stimulated eosinophils and in FMLP-stimulated neutrophils. We also found that eosinophils generate substantial amounts of O2- when treated with PAF alone. The high responsiveness of unstimulated or opsonized zymosan-stimulated eosinophils to PAF to generate O2- may be relevant to the pathological changes at the loci of allergic reactions where eosinophils and PAF are crucially involved.