Platelet uptake of serotonin (5-HT) during ethanol withdrawal in male alcoholics.

Changes in the kinetic variables of the platelet serotonin uptake, Km and Vmax, were studied in 7 male alcoholics, admitted for detoxification and in sex- and age-matched volunteers. On admission the alcoholics had lower Km values than reference subjects (p less than 0.05). During detoxification the Km values normalized. Vmax was normal throughout the study in spite of the changes in platelet count. The results of the study suggest that the affinity of serotonin to its uptake receptor is transiently increased after a period of heavy drinking.