[Phe1psi(CH2-NH)Gly2]nociceptin-(1-13)-NH2 is an agonist of the nociceptin (ORL1) receptor.
[Phe1psi(CH2-NH)Gly2]nociceptin-(1-13)-NH2, a pseudopeptide analog of nociceptin, has been shown to be a selective 'antagonist' of the nociceptin receptor in the isolated guinea pig ileum and mouse vas deferens preparations (Guerrini et al., 1998. Br. J. Pharmacol. 123, 163-165). However, in recombinant chinese hamster ovary cells expressing the human nociceptin receptor, we find that the pseudopeptide is a potent (IC50 = 7.5 nM) and fully efficacious inhibitor of forskolin-induced accumulation of cAMP, thus behaving as a pure 'agonist' rather than an antagonist of the receptor. The contrary behaviour of the pseudopeptide in smooth muscle and transformed cells may suggest that different nociceptin receptor types are being addressed in the two systems.
Unité de Neuropharmacologie Moléculaire, Institut de Pharmacologie et de Biologie Structurale, C.N.R.S. UPR 9062, Toulouse, France.
J L
JL
Butour
C
C
Moisand
C
C
Mollereau
J C
JC
Meunier
D000818:Animals; D016466:CHO Cells; D002461:Cell Line, Transformed; D005576:Colforsin / Q000494:pharmacology; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D018847:Opioid Peptides / Q000378:metabolism / Q000494:pharmacology*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000819:agonists* / Q000096:biosynthesis / Q000378:metabolism; D000094942:Nociceptin Receptor; D000097629:Nociceptin
D005576:Colforsin; D000242:Cyclic AMP; D018847:Opioid Peptides; D010446:Peptide Fragments; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C114149:nociceptin (1-13)-NH2, Phe(1)-psi(CH2-NH)-Gly(2)-