Nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the N/OFQ receptor (NOP). In this study using Chinese hamster ovary (CHO) cells expressing the human NOP (CHOhNOP) and GTPg35S binding and cAMP inhibition assays, we have characterised a novel N/ OFQ ligand, [( pF)Phe4]N/OFQ-(1–13)NH2, ([( pF)Phe4]). [( pF)Phe4] was produced by insertion of a fluorine atom into the para position of the phenyl ring of Phe4 of the truncated N/OFQ peptide N/OFQ-(1–13)NH2. In CHOhNOP membranes [( pF)Phe4] and N/OFQ-(1–13)NH2 stimulated GTPg35S binding with pEC50 (meanFS.E.M.) values of 9.55F0.01 and 8.94F0.5 ( P < 0.05), respectively. In whole CHOhNOP cells [( pF)Phe4] and N/OFQ-(1–13)NH2 inhibited forskolin stimulated cAMP formation with pEC50 values of 10.19F0.06 and 9.60F0.04, respectively ( P < 0.05). [( pF)Phe4] was more potent (f4 fold) than N/OFQ-(1–13)NH2. In both assays, the effects of [( pF)Phe4] and N/ OFQ-(1–13)NH2 were pertussis toxin sensitive and reversed by the NOP antagonists J-113397 (pA2/pKB values 7.89–8.53) and III-BTD (pA2/pKB values 7.27–7.96). [( pF)Phe4] is therefore a potent full agonist at NOP receptors that will be useful as pharmacological tool for defining the role of N/OFQ–NOP system in health and disease.
Effects of [(pF)Phe(4)]nociceptin/orphanin FQ-(1-13)NH2 on GTP gamma S-35 binding and cAMP formation in Chinese hamster ovary cells expressing the human nociceptin/orphanin FQ receptor
CALO', Girolamo;GUERRINI, Remo;
2002
Abstract
Nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the N/OFQ receptor (NOP). In this study using Chinese hamster ovary (CHO) cells expressing the human NOP (CHOhNOP) and GTPg35S binding and cAMP inhibition assays, we have characterised a novel N/ OFQ ligand, [( pF)Phe4]N/OFQ-(1–13)NH2, ([( pF)Phe4]). [( pF)Phe4] was produced by insertion of a fluorine atom into the para position of the phenyl ring of Phe4 of the truncated N/OFQ peptide N/OFQ-(1–13)NH2. In CHOhNOP membranes [( pF)Phe4] and N/OFQ-(1–13)NH2 stimulated GTPg35S binding with pEC50 (meanFS.E.M.) values of 9.55F0.01 and 8.94F0.5 ( P < 0.05), respectively. In whole CHOhNOP cells [( pF)Phe4] and N/OFQ-(1–13)NH2 inhibited forskolin stimulated cAMP formation with pEC50 values of 10.19F0.06 and 9.60F0.04, respectively ( P < 0.05). [( pF)Phe4] was more potent (f4 fold) than N/OFQ-(1–13)NH2. In both assays, the effects of [( pF)Phe4] and N/ OFQ-(1–13)NH2 were pertussis toxin sensitive and reversed by the NOP antagonists J-113397 (pA2/pKB values 7.89–8.53) and III-BTD (pA2/pKB values 7.27–7.96). [( pF)Phe4] is therefore a potent full agonist at NOP receptors that will be useful as pharmacological tool for defining the role of N/OFQ–NOP system in health and disease.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
