TABLE 5

In Vitro and In Vivo Pharmacologic Parameters for σ1 Receptor Ligands (Not Identified as Agonists)

σ1 ligandTissue for Ki assaysKi for σ1* (nM)Ki for σ2† (nM)ED50 in vivo‡ (nmol/kg)
FTC146Rat liver homogenate0.0025 (35,36)3642571
BD1047Guinea pig brain0.9 (40)47>1,000
NE100Guinea pig brain1.03 (41)211>1,000
F3Rat brain homogenate0.79 (42)277138
F4Rat brain homogenate2.30 (42)327>1,000

  • ↵* Reference radioligand 3H-pentazocine, except 18F-FTC146 for FTC146.

  • ↵† Reference radioligand 3H-DTG.

  • ↵‡ For preblocking of 11C-(S)-NR2B-SMe rat whole-brain uptake measured in this study.