Platelet-derived growth factor promotes human peripheral monocyte activation. Blood

Like in the polymorphonuclear leukocyte (PMN). the plate-let-derived growth factor (PDGF) purified to homogeneity is capable of inducing monocyte activation responses as evaluated by generation of superoxide anion (O ) from membrane-associated oxidase system, release of granule enzymes. and enhanced cell adherence and cell aggrega-tion. Superoxide anion release was maximized at 10 ng/mL PDGF and was comparable to that induced by i07 mol/L formyl-methionyl-leucyl-phenylalanine. The potency of PDGF to induce this response in monocytes was of the same magnitude as that observed in PMNs. Similarly. lysozyme release and monocyte adherence were also I N THE PROCESS of inflammation, a series of biochemi-cal events in leukocyte activation has been described.’ These include the binding ofchemoattractants to specific cel