Catalase-dependent peroxidative metabolism in the alveolar macrophage during phagocytosis

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Abstract

Evidence for the presence of peroxidative metabolism in rabbit alveolar macrophages (AM) has been obtained from the following observations: (a) catalase is present in high concentrations; (b) peroxidase activity could not be detected employing guaiacol as substrate; (c) the irreversible inhibition of AM catalase by aminotriazole served as a detection system for H2O2 and demonstrated increased intracellular H2O2 after phagocytosis; (d) formate oxidation, a marker of catalase-dependent peroxidations, occurs in resting AM and is increased by phagocytosis; (c) measurements of H2O2 accumulation in a dialysate of AM demonstrated twofold increase during phagocytosis; and (f) aminotriazole diminishes O2 utilization and 14CO2 production from labelled glucose and pyruvate. It is concluded that, while catalase-dependent H2O2 metabolism is not essential for particle entry, this pathway represents one of the metabolic pathways stimulated by particle entry in the AM.

Authors

J. Bernard L. Gee, Charles L. Vassallo, Paul Bell, James Kaskin, R. E. Basford, James B. Field