Transient increase in platelet monoamine oxidase B activity during early abstinence in alcoholics: Implications for research

Some earlier studies have suggested that platelet monoamine oxidase (MAO)-B activity should be determined at time points other than early in the abstinence phase. However, the optimal times for blood sampling have not been precise:lp defined. We therefore assessed platelet MAO-B activity repeatedly in 13 male alcohol-dependent patients over the 2 months after the end of a period of heavy alcohol intake. Twelve healthy men were used as controls. In the alcohol-dependent patients, platelet MAO-B activity was transiently increased from 2 to 6 weeks after the end of alcohol intake and the values during this time period were nor different from those of controls. Platelet MAO-B activity was, however, significantly lower in the alcohol-dependent patients at 1 week and at 2 months after the end of alcohol intake, in comparison to controls. It is concluded that the transient increase in platelet MAO-B activity after the end of alcohol intake in alcohol-dependent patients may conceal a difference from a control group. Therefore. it is suggested that when platelet MAO-B activity is determined, the preferential time point for obtaining those values in alcohol-dependent patients is after 2 months of abstinence.