PLATELET MONOAMINE-OXIDASE-B ACTIVITY IN DE-NOVO AND L-DOPA TREATED PARKINSONIAN-PATIENTS AND CONTROLS

Objective: Previous studies demonstrated controversial results regardi ng monoamine oxidase B (MAO-B) activity in platelets in the periphery in parkinsonian patients (PD). Subjects and Methods: Therefore we dete rmined platelet MAO-B activity in three age- and sex-matched groups of 17 untreated, so called ''de novo'' patients with Parkinson's disease (PD), 17 parkinsonian patients, receiving levodopa, and 17 controls b y a radio enzymatic assay. Results: No significant differences of MAO- B activity appeared. Conclusion: This result suggests that phenotypic determination of MAO-B activity in platelets may not be used as periph eral marker in PD and that levodopa treatment does not alter MAO-B act ivity in the periphery.