Abstract
The relative potencies of a new series of phencyclidine (PCP) analogs for the displacement of [3H]morphine binding from rat brain homogenates are well correlated with the relative antinociceptive potencies in the test of writhing induced by acetic acid (0.6%). One group of compoundss exerts a completely naloxone-reversible analgesic effect, while the effects of a second group are only partially reversed by naloxone. These findings and the structural differences between the two groups suggest that their analgesic activity is mediated through different opiate receptors. opiate receptors.
