Title

Effect of Tetrabenazine on the Striatal Uptake of Exogenous L-DOPA in Vivo: A PET Study in Young and Aged Rhesus Monkeys

Document Type

Article

Publication Date

6-2002

Department

Physics and Astronomy

Abstract

The effect of tetrabenazine (TBZ) pretreatment on the striatal uptake of exogenous L-DOPA in vivo was assessed noninvasively in rhesus monkeys by positron emission tomography (PET) using the tracer [18F]-FluoroDOPA (FDOPA). Paired studies were done comparing baseline vs. TBZ treatment on the uptake of FDOPA, a measure of aromatic L-amino acid decarboxylase (AAAD) activity. Results show increased AAAD activity with TBZ treatment. These results suggest that the action of TBZ as a dopamine antagonist dominates more than its expected action as a potent vesicular monoamine transporter (VMAT2) inhibitor. Results also showed diminished responsivity of AAAD to TBZ challenge in aged monkey brain.

Publication Title

Synapse

DOI

10.1002/syn.10077