Effects of cocaine on the respiratory burst of murine macrophages

Cocaine is a central nervous stimulant with a major potential for abuse. It is used clinically as a local anesthetic and vasoconstrictor. The effects of cocaine on the immune system have not been studied in depth. In this study, we have investigated the effects of cocaine on the respiratory burst (RB) of murine macrophages (M phi). The RB was measured by determining the increase in chemiluminescence. Both peritoneal and alveolar M phi were isolated from cocaine-exposed mice and saline-exposed controls. Cocaine was administered by the intraperitoneal, intravenous, and intramuscular route. Both peritoneal and alveolar M phi from cocaine-exposed mice showed an increase in chemiluminescence when compared with M phi from matched controls. This effect was seen as early as one hour after cocaine exposure and lasted for up to 48 hours. Intraperitoneal injection of cocaine metabolites did not affect the RB. Macrophages exposed to cocaine in vitro failed to respond by an increase in RB. These findings indicate that cocaine induces the production of reactive oxygen intermediates (ROI) and suggests possible changes in M phi functions.