Decreased Fc-receptor binding in human monocytes exposed to ethanol in vitro.

Human blood monocytes were incubated with or without ethanol (14 mM-220 mM, initial concentration) in non-sealed wells in an atmosphere of 5% CO2 in air for various time periods. The actual ethanol concentration was assayed in the media at the beginning and at the end of each incubation period. No change in ethanol content was found after 5 or 15 min incubation, while a reduction to about 70% of the initial concentration was observed after 6 hr incubation. Binding of IgG-opsonized particles to the Fc-receptors was tested after ethanol exposure of the cells. An initial concentration of 14 or 28 mM ethanol caused no difference from controls, neither did incubation in 55 mM ethanol for 5 min. Monocyte incubated in 55 mM ethanol for 15 min showed reduced binding of particles, and further reduction was obtained by increasing the ethanol concentration. Six hr incubation in 55 mM ethanol caused no further reduction in binding capacity. Reduced binding of test particles to Fc-receptors after ethanol incubation was demonstrated with variable amounts of test particles, as well as variable length of the binding assay period. There was no change in viability, morphology or spreading ability of the monocytes after ethanol treatment.