title: Activation of the nociceptin/orphanin FQ system is unable to reverse CRF2 receptor mediated anorexia in the rat.
abstract: Central injection of Nociceptin/Orphanin FQ (N/OFQ), inhibits the anorectic effect of corticotropin-relasing factor (CRF) and stress in rats. Recently, Urocortin II (Ucn II) and Urocortin III (Ucn III), two selective CRF(2) receptor agonists, have been identified. Here, we investigated the effect of intracerebroventricular (ICV) injection of 0.25, 0.75, 1.50 or 3 nmol/rat of Ucn II or Ucn III on food and water intake in food deprived rats. The effect of N/OFQ on Ucn II and UCNIII-induced anorexia was also studied. Results showed a greater inhibition of food consumption by Ucn II than Ucn III. Pretreatment with N/OFQ (0.25-2.0 nmol/rat) did not block the effects of Ucn II and UCNIII. Conversely, injection of N/OFQ (0.25-2.0 nmol/rat) blocked the anorectic effect of CRF (0.1 nmol/rat). These findings suggest that N/OFQ selectively prevent the anorectic effect mediated by activation of the CRF(1) receptor system.
authors.affiliation: Department of Experimental Medicine and Public Health, University of Camerino, Via Scalzino 3, 62032 Camerino (MC), Italy.
authors.forename: Amalia
authors.initials: A
authors.lastname: Fedeli
authors.forename: Federica
authors.initials: F
authors.lastname: Policani
authors.forename: Massimo
authors.initials: M
authors.lastname: Ubaldi
authors.forename: Andrea
authors.initials: A
authors.lastname: Cippitelli
authors.forename: Maurizio
authors.initials: M
authors.lastname: Massi
authors.forename: Roberto
authors.initials: R
authors.lastname: Ciccocioppo
mesh_terms: D000818:Animals; D000855:Anorexia / Q000378:metabolism*; D004326:Drinking / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D018847:Opioid Peptides / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000502:physiology*; D054832:Urocortins / Q000008:administration & dosage / Q000502:physiology; D000097629:Nociceptin
chemical_list: D018847:Opioid Peptides; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; D000097629:Nociceptin; C101531:CRF receptor type 2