Binding of 125I‐iodovinyltetrabenazine to CNS vesicular monoamine transport sites

Abstract
Binding characteristics of a novel radioiodinated tetrabenazine (TBZ) analog (iodovinyltetrabenazine; 125I‐TBZ‐Fraction I) were evaluated. In rat striatal homogenates, 125I‐TBZ‐I displayed a pharmacological profile consistent with specific binding to vesicular monoamine transport (VMAT) sites. In vitro autoradiographic studies using rat brain sections; further demonstrated that 125I‐TBZ‐I labeled the regions rich in VMAT sites, and it may be a useful marker for these sites. This novel radioiodinated ligand, with high specific activity and high binding affinity, may provide a powerful tool for the in vitro assessment of neuronal loss in various neurodegenerative diseases.