title: Morphiceptin ( beta-casomorphin (1-4) amide): a peptide opioid antagonist in the field stimulated rat vas deferens.
abstract: The effect of Morphiceptin (H-Tyr-Pro-Phe-Pro-NH2) on opioid inhibition of field stimulated rat vas deferens (RVD) was studied. The morphiceptin was found to produce a weak inhibition of the twitch response of the RVD. In addition morphiceptin antagonized full agonists acting on the same receptor system (i.e. beta-endorphin selective antagonist for the delta receptor system of RVD by virtue of being a weak partial agonist.
mesh_terms: D000818:Animals; D002364:Caseins; D004558:Electric Stimulation; D004723:Endorphins / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology*; D001615:beta-Endorphin
chemical_list: D002364:Caseins; D004723:Endorphins; D009270:Naloxone; D001615:beta-Endorphin; C021968:beta-casomorphins; C028889:morphiceptin