PLATELET MAO-B ACTIVITY AND SEROTONIN CONTENT IN PATIENTS WITH DEMENTIA - EFFECT OF AGE, MEDICATION, AND DISEASE

This study aimed at determining the effect of drug therapy, age and ty pe of dementia on biological markers. Both platelet monoamine oxidase type B (MAO-B) activity and serotonin content of 57 demented patients and 20 control subjects were determined. Platelet MAO-B activity was m easured using [C-14]tyramine as substrate. Serotonin content was deter mined by HPLC-EC method. Increased platelet serotonin content and plat elet count was found in patients with dementia compared to controls. A positive correlation was experienced between platelet MAO-B activity, platelet serotonin content and age. Platelet MAO-B activity was highe r in the haloperidol treated group, compared with patients treated wit h anxyolitics. The main original finding of the present study is that platelet serotonin content is increased in demented patients with delu sions compared to dementia without complications (p = 0.006). It seems , that platelet MAO-B activity is influenced mainly by drug therapy, w hile serotonin content rather reflects clinical characteristics in dem entia.