COCAINE ALTERS THE RESPIRATORY BURST AND PHAGOCYTIC-ACTIVITY OF MURINE MACROPHAGES

The effects of cocaine on the respiratory burst (RB) and the phagocytic activity of murine macrophages (MΦ) were studied. C57BL/6 mice were injected intraperitoneally with various concentrations of cocaine or appropriate vehicle. Peritoneal and alveolar MΦ were isolated from mice and cultured in vitro. Both alveolar and peritoneal MΦ from cocaine-exposed mice exhibited an increase in the RB when compared with MΦ from saline-injected controls. This increase in the RB was apparent 60 min after injection and persisted for at least 48 hr. Injection of the cocaine metabolites, ecgonine methyl ester hydrochloride and ecgaonine hydrochloride, did not affect the RB. The increase in the RB was correlated with an increase in phagocytosis of opsonized zymosan in vitro. However, an in vivo phagocytic assay using mice injected ip with cocaine, which was subsequently followed by sheep erythrocytes, demonstrated the opposite effect. Fewer peritoneal MΦ from cocaine-injected mice were observed with ingested erythrocytes. These data underscore the complex effects of cocaine on MΦ functions. © 1993 Academic Press, Inc.