PRODUCTION OF HYDROGEN-PEROXIDE BY ALVEOLAR MACROPHAGES - EFFECT OF BARBITURATES

Production of hydrogen peroxide by rat lung alveolar macrophages repre sents one of the key events in the inflammatory process. For the inter pretation of the in vitro measurements it is important to control all possible interfering influences. The present work documents that the t ype of anaesthesia might critically influence the observed results. H2 O2 production was measured in isolated rat alveolar macrophages by lum inol chemiluminescence catalyzed by horseradish peroxidase. Three diff erent mechanisms of H2O2 production were observed after stimulation of cells with a chemotactic peptide (FMLP), phorbol ester (PMA), and dur ing cell adherence. All these activities were influenced independently by the treatment with barbiturates, which both stimulated or inhibite d the H2O2 production, depending on the barbiturate concentration. As the effective barbiturate concentrations were found to be within the r ange used for the anaesthesia of experimental animals, the presented r esults imply that barbiturates are not suitable for experiments in whi ch the production of reactive oxygen species by phagocytes is measured , and that other anaesthetics should be tested.