Fig. 2.

Displacement of [³H]naloxone binding to MOPr. a–c Competition displacement binding curves for the displacement of ³H-naloxone binding by GSK1521498, naltrexone, and 6-β-naltrexol to membranes prepared from HEK293 cells expressing the human MOPr. d Kinetics of [³H]naloxone dissociation from MOPr in the absence and presence of GSK1521498, naltrexone and 6-β-naltrexol (all at 1 μM). Mean t_1/2 values for [³H]naloxone dissociation in the presence of each drug are given with 95 % confidence limits