In vitro and in vivo pharmacological characterization of J-113397, a potent and selective non-peptidyl ORL1 receptor antagonist

Eur J Pharmacol. 2000 Aug 18;402(1-2):45-53. doi: 10.1016/s0014-2999(00)00520-3.

Abstract

1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl -1, 3-dihydro-2H-benzimidazol-2-one (J-113397) was found to be the first potent nonpeptidyl ORL1 receptor antagonist (K(i): cloned human ORL1=1.8 nM) with high selectivity over other opioid receptors (K(i): 1000 nM for human mu-opioid receptor, >10,000 nM for human delta-opioid receptor, and 640 nM for human kappa-opioid receptor). In vitro, J-113397 inhibited nociceptin/orphanin FQ-stimulated [35S]guanosine 5'-O-(gamma-thio)triphosphate (GTP gamma S) binding to Chinese Hamster Ovary (CHO) cells expressing ORL1 (CHO-ORL1) with an IC(50) value of 5.3 nM but had no effect on [35S]GTP gamma S binding by itself. Schild plot analysis of the [35S]GTP gamma S binding assay and cAMP assay using CHO-ORL1 indicated competitive antagonism of J-113397 on the ORL1 receptor. In CHO cells expressing mu-, delta- or kappa-opioid receptors, J-113397 had no effects on [35S]GTP gamma S binding up to a concentration of 100 nM, indicating selective antagonism of the compound on the ORL1 receptor. In vivo, J-113397, when administered subcutaneously (s.c.), dose-dependently inhibited hyperalgesia elicited by intracerebroventricular (i.c.v.) administration of nociceptin/orphanin FQ in a tail-flick test with mice. An in vitro binding study using mouse brains indicated that J-113397 possesses high affinity for the mouse ORL1 receptor (K(i): 1.1 nM) as well as the human receptor. In summary, J-113397 is the first potent, selective ORL1 receptor antagonist that may be useful in elucidating the physiological roles of nociceptin/orphanin FQ.

MeSH terms

  • Analgesics, Opioid / metabolism
  • Analgesics, Opioid / pharmacology*
  • Animals
  • Autoradiography
  • Benzimidazoles / metabolism
  • Benzimidazoles / pharmacology*
  • Binding, Competitive / drug effects
  • Brain / drug effects
  • Brain / metabolism
  • CHO Cells
  • Cloning, Molecular
  • Cricetinae
  • Cyclic AMP / metabolism
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
  • Humans
  • Male
  • Mice
  • Mice, Inbred ICR
  • Narcotic Antagonists*
  • Opioid Peptides / metabolism
  • Pain Measurement / drug effects
  • Piperidines / metabolism
  • Piperidines / pharmacology*
  • Receptors, Opioid

Substances

  • Analgesics, Opioid
  • Benzimidazoles
  • J 113397
  • Narcotic Antagonists
  • Opioid Peptides
  • Piperidines
  • Receptors, Opioid
  • nociceptin, Tyr(1)-
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • nociceptin receptor
  • Cyclic AMP