Fluoride prevents degranulation of the azurophilic and specific granules in electropermeabilized neutrophils.J

Abstract: The effect of A1F4 on the degranulation pro-cess in human neutrophils was investigated. In intact neutrophils, A1F4 induced degranulation, whereas in electropermeabilized neutrophils A1F4 did not stimulate degranulation. In electropermeabiized neutrophils, fluo-ride ions proved to be inhibitory for the degranulation induced by addition of Ca2 and/or GTP-y-S. Another phosphatase inhibitor, okadaic acid, inhibited degranula-tion induced by Ca2 or by GTP-y-S but not degranula-tion induced by the combination of Ca2 plus GTP--y-S. It is concluded that under suboptimal conditions of stimu-lation with Ca24 or GTP-7-S, protein dephosphorylation plays an important role in the degranulation response in human neutrophils. J. Leukoc. Biol. 55: 489-495; 1994. Key Words: neutrnphils d#{128}granulation ‘ electmpermeabilization fluorid