The role of salsolinol in alcohol intake and withdrawal

We studied the urinary excretion of the tetrahydroisoquinoline (TIQ) salsolinol, formed from acetaldehyde and dopamine, in both severely and moderately dependent alcoholics during withdrawal from alcohol and subsequent challenge with an acute dose of alcohol and L-dopa, and compared these results with controls. Plasma acetaldehyde and alcohol levels in a sub-population of severely dependent withdrawn alcoholic and control subjects following an acute dose of alcohol were also determined. Salsolinol excretion during the first 4 days of alcohol withdrawal was variable but 10 out of 14 alcoholics showed an increasing trend from day 1 to day 3 and 4 of alcohol withdrawal. L-dopa administration raised salsolinol excretion in controls and withdrawn alcoholics to a uniform extent. Loading of the withdrawn alcoholics with an acute dose of alcohol did not cause an increase in urinary salsolinol concentration (despite increased plasma acetaldehyde). Indeed, 24 h following acute alcohol administration, salsolinol excretion rates were depressed in the alcoholics but not in the controls.