Macrophages from different sources, their production of chemiluminescence under various stimuli and the effects of PGE2 and drugs.

We are currently characterizing different macrophages sub-populations according to their release of oxygen free radicals (measured as chemiluminescence) under various stimuli and their responses to drugs and mediators. Mouse macrophages were obtained by peritoneal or lung lavage and stimulated in vitro with opsonized zymosan (OpZ) or the calcium ionophore A23187. Chemiluminescence was measured in a luminometer and responses obtained after 5 min expressed as percentages of standard responses to the stimuli. Almost identical dose-response curves to OpZ were obtained with peritoneal and alveolar macrophages, while the dose-response curve of peritoneal macrophages to A23187 was much shallower. The response to A23187 was generally much weaker than that to OpZ and in both types of macrophages PGE2 was a more effective inhibitor of OpZ-induced chemiluminescence than of that induced by A23187. The response to OpZ in peritoneal macrophages was inhibited in a dose-related manner by both PGE2 and superoxide dismutase, but not by indomethacin, d-penicillamine, piroxicam or phenylbutazone. OpZ but not A23187, is a suitable stimulus for pharmacological studies on macrophage chemiluminescence.