Role of superoxide anion radicals in ethanol metabolism by blood monocyte-derived human macrophages

The effects of a number of additives on the rate of conversion of ethanol (1 mg/ml; 21.7 mM) to acetate by monolayers of blood monocyte-derived human macrophages were investigated. The additives studied were superoxide dismutase (SOD; 1,500 U/ml), catalase (1,500 U/ml), tetrahydrofurane (20 mM), and PMA (20 nM), either singly or in various combinations. SOD, catalase, SOD plus catalase, tetrahydrofurane, and tetrahydrofurane plus SOD inhibited ethanol oxidation by 49.2, 12.1, 52.9, 60.4, and 66.8%, respectively. PMA caused a 4.0-8.3-fold increase in the rate of ethanol metabolism and this increase was completely suppressed in the presence of SOD. The data indicate that a substantial proportion of the ethanol metabolism by both unstimulated and PMA-stimulated blood monocyte-derived macrophages was dependent on the generation of superoxide anion radicals.