Platelet monoamine oxidase B activity in "de novo" and l-dopa treated parkinsonian patients and controls.

OBJECTIVE: Previous studies demonstrated controversial results regarding monoamine oxidase B (MAO-B) activity in platelets in the periphery in parkinsonian patients (PD). SUBJECTS AND METHODS: Therefore we determined 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 by 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 peripheral marker in PD and that levodopa treatment does not alter MAO-B activity in the periphery.