In vitro effects of ethanol, acetaldehyde and fatty acid ethyl esters on human erythrocytes.

In vitro experiments were performed to determine if ethanol was metabolized by human erythrocytes and to investigate if ethanol or its metabolites, acetaldehyde and fatty acid ethyl esters, affected erythrocyte morphology and stability. No detectable metabolism of ethanol was found in erythrocytes, although ethanol itself caused an elevated rate of spontaneous haemolysis in erythrocyte preparations. Physiologically attainable levels of ethanol were found to stabilize erythrocytes against haemolysis induced by sodium hypochlorite, and the presence of ethanol caused a decrease in erythrocyte reactive oxygen species levels, although the mechanism for such a process is unknown. Both physiologically attainable and higher levels of acetaldehyde had no effects on erythrocyte morphology and stability even after a 16 h exposure. Fatty acid ethyl esters caused structural changes and instability in erythrocytes in vitro, but whether such changes occur in vivo has not been established. The results of these studies suggest that the deleterious effects of ethanol consumption on erythrocytes in vivo may be, at least in part, the result of direct effects of unmetabolized ethanol on erythrocyte components.