Glycoprotein sialyl- and galactosyl transferase activities in erythrocyte membranes in alcoholic patients and healthy controls.

In investigating possible mechanisms underlying carbohydrate deficiencies in serum transferrin and erythrocyte membranes in alcoholics, a total of 27 alcoholic patients and 27 healthy controls were examined for the activities of sialytransferase in serum and erythrocyte membranes and galactosyltransferase in erythrocyte membranes. The enzymes were assayed with endogenous and different exogenous glycoprotein acceptors and with [14C] CMP-sialic acid and [14C] UDP-galactose as substrates. No decrease in enzyme activities were found in alcoholic patients compared to controls, indicating that chronic ethanol abuse does not exert any direct inhibitory effect on these glycosyltransferases in isolated erythrocyte membranes or on sialytransferase in serum. Further studies of the effect of ethanol on the metabolism of complex carbohydrates are clearly necessary.