Halothane inhibits the microbicidal oxidative activity of pulmonary alveolar macrophages.

The effect of clinical concentrations of halothane on the microbicidal oxidative activity of pulmonary alveolar macrophages (PAM) was investigated. PAM oxidative activity [generation of the microbicidal oxidative intermediates hydrogen peroxide (H2O2), hydroxyl radicals (OH), and superoxide anions (O2-)] was assessed using luminol and lucigenin chemiluminescence (CL). Whereas luminol CL is an indicator of oxidative activity due to H2O2, OH, or O2-, lucigenin CL provides an ultrasensitive measurement of O2- generation. The use of both chemoluminigenic probes thus enables a detailed analysis of PAM oxidative function. Exposure of PAM to 3, 2, and 1% halothane vaporized in air significantly inhibited both luminol (23-46%) and lucigenin (30-51%) CL responses, P less than 0.01. Halothane-treated PAM exposed to air recovered to the extent that their luminol CL responses were significantly greater than control (no halothane) experiments. Lucigenin reaction mixtures given halothane then air showed less inhibition than PAM treated with halothane only. These results suggest that 1) the generation of O2- and to a lesser extent other oxidative metabolites are decreased following halothane exposure, and 2) this inhibition is reversible.