Superoxide anion and hydrogen peroxide production by chemically elicited peritoneal macrophages-Induction by multiple nonphagocytic stimuli

The ability of a number of stimulants to activate an oxidative burst (OB) in oil-elicited guinea pig peritoneal exudate macrophages (MPs) was examined. The parameters of the OB were the generation and extracellular release of Superoxide anions (O₂^-) and hydrogen peroxide (H₂O₂). We found that: (1) The cocarcinogen and skin irritant phorbol myristate acetate (PMA) was the most potent OB activator-The weak cocarcinogen 4-O-methyl PMA was a proportionally less effective OB activator; (2) The lectins concanavalin A (Con A) and wheat germ agglutinin (WGA), but not soybean, Lotus, and pokeweed lectins, were also quite effective OB activators-The ability of Con A to stimulate O₂^- production was abolished by succinylation and could be prevented by the presence of α-methyl-D-mannoside; (3) Other stimulators of an OB in MPs were: N-formyl-methionyl peptides, opsonized zymosan, the Ca²⁺ ionophore A23187, phospholipase C, NaF, antimacrophage antibody, microtubule-disrupting drugs, and sodium nitroprusside-O₂^- generation induced by A23187 (but not that stimulated by PMA) was dependent on extracellular Ca²⁺; (4) The amount of O₂^- produced per cell was higher at low cell densities; (5) The addition of Superoxide dismutase (SOD) to the medium totally prevented the detection of O₂^- and augmented twice the amount of H₂O₂ recovered; (6) Pretreatment of MPs with the SOD inhibitor sodium diethyldithiocarbamate had no effect on the release of O₂^- but blocked H₂O₂ release in a dose-dependent manner. These data were interpreted as indicating that the bulk of H₂O₂ was derived by enzymatic dismutation of O₂^-; (7) The common mechanism by which such a variety of stimuli provoke an OB in MPs was not elucidated. No evidence was found to suggest a role for a cyclic nucleotide messenger.