Chemiluminescence from mouse resident macrophages: characterization and modulation by arachidonate metabolites

Oxidative burst dependent chemiluminescence (CL), generated by mouse resident peritoneal and alveolar macrophages obtained by peritoneal and lung lavage, has been studied using a lumanol-dependent assay. Alveolar macrophages generated greater CL in response to opsonized zymosan (OpZ, 0.017-0.67 mg/ml) than did peritoneal cells, but the former were less sensitive to inhibition by joint cyclo-oxygenase/lipoxygenase inhibitors and superoxide dismutase. Responses of peritoneal macrophages to OpZ and calcium ionophore A23187 (0.1-0.5 microM) were small in comparison to responses of C. parvum-elicited cells, while FMLP (2-20 microM) was ineffective. Arachidonic acid alone (40-80 microM) generated slight CL from resident peritoneal macrophages. When added with OpZ (0.017 mg/ml), arachidonate (40 microM) initially enhanced, then inhibited CL, the inhibition being indomethacin (10 microM) sensitive. These data indicate that modulation of resident macrophage CL by arachidonate products differs somewhat from that reported for elicited macrophages.