Reduced 3H-imipramine binding but unaltered 3H-serotonin uptake in platelets of adolescent enuretics

High affinity 3H-imipramine binding and 3H-serotonin uptake to platelets was evaluated in nine untreated adolescent enuretics (ages 13-18) and nine age- and sex-matched controls. A significant decrease in the maximal binding of 3H-imipramine (Bmax) was observed in the enuretics as compared to the controls. No alteration in the affinity of 3H-imipramine to its binding sites (Kd) or in serotonin uptake kinetic parameters (Vmax, Km) was detected. The lack of correlation between Bmax and Vmax values might indicate that the binding sites for imipramine and the sites for serotonin uptake are not identical.