Synthesis and preliminary pharmacological evaluation of a new putative radioiodinated AMPA receptor ligand for molecular imaging

Abstract

Summary A new (radio)iodinated AMPA receptor ligand has been developed and pharmacologically evaluated in vitro and ex vivo using rodents. The new radioligand was directly labeled by electrophilic radioiodo-destannylation with iodine- 131 in high radiochemical yields of 97% within 2 min. The new radioligand showed an excellent initial brain uptake of 2.1%ID/g at 10 min post injection, but a fast wash-out reduced the uptake by about 10-fold at 60 min post injection. Due to high nonspecific binding accompanied with a uniform distribution in brain tissue, however, the new radiotracer appears not suitable for AMPA receptor imaging in vivo.