PET Imaging of the Adenosine A Receptor in the Rotenone-Based Mouse Model of Parkinson's Disease with [F]FESCH Synthesized by a Simplified Two-Step One-Pot Radiolabeling Strategy.

The adenosine A receptor (AR) is regarded as a particularly appropriate target for non-dopaminergic treatment of Parkinson's disease (PD). An increased AR availability has been found in the human striatum at early stages of PD and in patients with PD and dyskinesias. The aim of this small animal positron emission tomography/magnetic resonance (PET/MR) imaging study was to investigate whether rotenone-treated mice reflect the aspect of striatal AR upregulation in PD. For that purpose, we selected the known AR-specific radiotracer [F] and developed a simplified two-step one-pot radiosynthesis. PET images showed a high uptake of [F] in the mouse striatum. Concomitantly, metabolism studies with [F] revealed the presence of a brain-penetrant radiometabolite. In rotenone-treated mice, a slightly higher striatal AR binding of [F] was found. Nonetheless, the correlation between the increased AR levels within the proposed PD animal model remains to be further investigated.