Dopamine modulating drugs influence striatal (+)-[11C]DTBZ binding in rats: VMAT2 binding is sensitive to changes in vesicular dopamine concentration
Article first published online: 21 AUG 2008
Copyright © 2008 Wiley-Liss, Inc.
Volume 62, Issue 11, pages 873–876, November 2008
How to Cite
Tong, J., Wilson, A. A., Boileau, I., Houle, S. and Kish, S. J. (2008), Dopamine modulating drugs influence striatal (+)-[11C]DTBZ binding in rats: VMAT2 binding is sensitive to changes in vesicular dopamine concentration. Synapse, 62: 873–876. doi: 10.1002/syn.20573
- Issue published online: 21 AUG 2008
- Article first published online: 21 AUG 2008
- Manuscript Accepted: 17 JUN 2008
- Manuscript Received: 2 JUN 2008
- vesicular monoamine transporter;
- positron emission tomography
Binding of (+)-[11C]DTBZ (dihydrotetrabenazine) to the striatal vesicular monoamine transporter (VMAT2) is widely considered to be a stable marker of dopamine neurone integrity. However, we now find that specific binding of a tracer dose of (+)-[11C]DTBZ is modestly increased in rat striatum following dopamine depletion with α-methyl-p-tyrosine (α-MPT, +14%) or d-amphetamine (d-AMPH, 20 mg/kg, +12%) and decreased following dopamine elevation with γ-hydroxybutyrate (GHB, −16%) or levodopa (−20%). We suggest that in vivo (+)-[11C]DTBZ binding in imaging studies is subject to competition by vesicular dopamine and, in this respect, is not a “stable” dopamine biomarker as is generally assumed. Synapse 62:873–876, 2008. © 2008 Wiley-Liss, Inc.