BP in anterior and posterior putamen: 1.25 ± 0.17 and 1.20 ± 0.16, respectively (centrum semiovale as reference region) [19] DVR in striatum (clustered gray matter as reference region) 1.674 [141]
Preblocking with Tozadenant or Preladenant reduced total binding (SUV) to the level of extrastriatal (cerebellum) binding at the highest dose in rhesus monkeys. Also <15% reduction in cerebellar with preblocking was observed [146].
SCH442416
= 0.048/selectivity over A1, , A3 >20000-fold [147]
BP 0.99 ± 0.21 (cerebellum as reference region) [15] 2.47 ± 0.84 (cerebellum as reference region) [148]
Preblocking with Preladenant led to dose-dependent receptor occupancy in the striatum (at 200 mg 88–105%), with corresponding decrease in SCH442416 binding () [148]. Preblocking with vipadenant led to approximately 3-4-fold reduction SCH442416 in caudate and putamen and also to an up to 2-fold reduction in cerebellum. Dose-dependent receptor occupancy observed in putamen, caudate, nucleus accumbens, and cerebellum (on average from 74% to 95% with 2.5–100 mg dose), but not in thalamus [149].