Unaltered platelet [3H]-imipramine binding in dementia of the Alzheimer type.

High-affinity [3H]-imipramine binding to platelets was evaluated in 11 patients suffering from dementia of Alzheimer type (DAT) in comparison to 12 normal controls. The [3H]-imipramine binding values (Bmax and Kd) did not differ between the DAT patients and the controls. Previous studies have demonstrated hypofunction of central serotonergic system in this disease, including reduced imipramine binding to brain. Thus, it seems that the low imipramine binding in DAT is confined to the brain tissue and not reflected in the platelets.