Role of tyrosine phosphorylation in the signalling of superoxide anion generation in platelet-activating-factor-stimulated peritoneal macrophages

Abstract

The signalling pathway(s) involved in the activation of superoxide anion (O−2) generation by platelet-activating factor (PAF) are not well understood, But elevations of sn-l,2-diacylglycerol and intracellular calcium contribute to activation by stimulating protein kinase C activity. Since recent studies have suggested that tyrosine phosphorylation may also be a component of the signalling of O−2 generation in human neutrophils, we have investigated whether PAF stimulates tyrosine phosphorylation in guinea pig and rat macrophages. PAF (10 nM) stimulated tyrosine phosphorylation within 10−30 s, coinciding with the onset of the O−2 generation in guinea pig peritoneal macrophages. At 30 min afte..