title: Studies on opioid receptor selectivity of beta-endorphin antagonists.
abstract: Opioid receptor selectivity of several beta-endorphin (beta-EP) analogs which antagonize beta-EP-induced analgesia has been assessed using partially selective binding assays. Although the apparent affinity dissociation constant of beta-EP in these assays varies from 0.2 to 360 nm, the potency of beta-EP antagonists relative to beta-EP remains largely unchanged. It is unlikely that differences in receptor affinities can account for the antagonist properties of these analogs in vivo.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004723:Endorphins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007700:Kinetics; D011817:Rabbits; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D013329:Structure-Activity Relationship; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D011957:Receptors, Opioid; D001615:beta-Endorphin