title: beta-endorphin-(1-27) is an antagonist of beta-endorphin analgesia.
abstract: beta h-Endorphin-(1-27), a naturally occurring fragment of human beta-endorphin (beta h-endorphin), diminishes the analgesic effect of beta h-endorphin when coinjected intra-cerebroventricularly into mice. A parallel shift in the dose-response curve of beta h-endorphin in the presence of beta h-endorphin-(1-27) suggests competition at the same site. The potency of beta h-endorphin-(1-27) in antagonizing analgesia is greater than 4 times greater than that of the opiate antagonist naloxone.
mesh_terms: D000698:Analgesia; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004723:Endorphins / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D009270:Naloxone / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D010446:Peptide Fragments; D011957:Receptors, Opioid; D009270:Naloxone; D001615:beta-Endorphin; C035581:beta-endorphin (1-27)