Modulation of human granulocyte and monocyte chemiluminescence responses: evidence for distinct free radical...

Using a previously described luminol-dependent photometric chemiluminescence (CL) assay we have investigated the relative significance of the free radicals in the CL phenomenon associated with the respiratory burst of granulocytes and monocytes. The O-2 scavenger, superoxide dismutase, quenches approximately 50% of CL emission from resting and stimulated cells of both types. CL production from granulocytes and monocytes, in the presence of catalase, indicates that H2O2 plays a much less significant role in monocyte light emission than in that of granulocytes. Sodium azide, an 1O2 scavenger and potent inhibitor of peroxidase, and sodium benzoate, an OH. scavenger, both induced 90% reductions of light output from both cell types in resting or stimulated states. The distinct effects of cytochalasins on granulocytes and monocytes further suggest distinct CL generating mechanisms for each cell type. No difference was observed between granulocyte and monocyte CL response in chronic granulomatous disease (CGD) and other clinically related but unknown phagocyte metabolic disorders, whereas selective CL response abnormalities were observed in patients with severe isolated phagocyte chemotaxis defects.