Description
PL 017, a morphiceptin analog, is a selective µ opioid receptor agonist (IC50= 5.5 and > 10000 nM for inhibition of 125I-FK 33,824 and 125I-DADLE binding to µ and δ sites respectively). Although the affinity of PL017 for µ-sites is lower than that of morphine, PL 017 is more potent than morphine in all in vitro studies, suggesting a difference in the way in which peptide and alkaloid activate µ-receptors