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Updated: May 5, 2026
A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices
Published on: August 11, 2021
Chronic monoamine oxidase-B inhibitor treatment blocks monoamine oxidase-A enzyme activity
Jasmin Bartl1, Thomas Müller, Edna Grünblatt
1Hospital of Child and Adolescent Psychiatry, University of Zurich, Winterthurerstr. 180, Room L84/86, 8057, Zurich, Switzerland, jasmin.bartl@kjpdzh.ch.
Abstract:
Patients with Parkinson's disease receive selective irreversible monoamine oxidase (MAO)-B inhibitors, but their effects on MAO-A activity are not known during long-term application. We determined MAO-A inhibition in plasma samples from patients with MAO-B inhibitor intake or without MAO-B inhibitor treatment and from healthy controls. We detected a 70 % reduction of MAO-A activity in patients with MAO-B inhibitor therapy in comparison to the other groups. Our results suggest that treatment with MAO-B inhibitor may also influence MAO-A activity in vivo, when administered daily.
Insights
Long-term use of monoamine oxidase (MAO)-B inhibitors for Parkinson's disease significantly reduces MAO-A activity. This study reveals an unexpected impact of MAO-B inhibitors on MAO-A levels in patients.
Area of Science:
- Biochemistry
- Neuroscience
- Pharmacology
Background:
- Parkinson's disease treatments often involve monoamine oxidase (MAO) inhibitors.
- Selective irreversible MAO-B inhibitors are commonly prescribed.
- The impact of long-term MAO-B inhibitor use on MAO-A activity remains unclear.
Purpose of the Study:
- To investigate the effect of long-term MAO-B inhibitor therapy on MAO-A activity in Parkinson's disease patients.
- To compare MAO-A activity in patients receiving MAO-B inhibitors versus those not receiving them and healthy controls.
Main Methods:
- Plasma samples were collected from Parkinson's disease patients on MAO-B inhibitor therapy.
- Plasma samples were collected from Parkinson's disease patients not on MAO-B inhibitor therapy.
- Plasma samples were collected from healthy controls.
- MAO-A activity was measured in all plasma samples.
Main Results:
- A significant 70% reduction in MAO-A activity was observed in patients undergoing MAO-B inhibitor therapy.
- MAO-A activity levels were comparable between patients without MAO-B inhibitor treatment and healthy controls.
Conclusions:
- Daily, long-term administration of MAO-B inhibitors may lead to a substantial decrease in MAO-A activity in vivo.
- This finding suggests a potential interaction between MAO-B inhibitors and MAO-A activity that warrants further investigation in Parkinson's disease management.
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