1
|
Angelico P, Barchielli M, Lazzeri M, Guerrini R, Caló G. Nociceptin/Orphanin FQ and Urinary Bladder. Handb Exp Pharmacol 2019; 254:347-365. [PMID: 30430260 DOI: 10.1007/164_2018_182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Following identification as the endogenous ligand for the NOP receptor, nociceptin/orphanin FQ (N/OFQ) has been shown to control several biological functions including the micturition reflex. N/OFQ elicits a robust inhibitory effect on rat micturition by reducing the excitability of the afferent fibers. After intravesical administration N/OFQ increases urodynamic bladder capacity and volume threshold in overactive bladder patients but not in normal subjects. Moreover daily treatment with intravesical N/OFQ for 10 days significantly reduced urine leakage episodes. Different chemical modifications were combined into the N/OFQ sequence to generate Rec 0438 (aka UFP-112), a peptide NOP full agonist with high potency and selectivity and long-lasting duration of action. Rec 0438 mimicked the robust inhibitory effects of N/OFQ on rat micturition reflex; its action is solely due to NOP receptor stimulation, does not show tolerance liability after 2 weeks of treatment, and can be elicited by intravesical administration. Collectively the evidence summarized and discussed in this chapter strongly suggests that NOP agonists are promising innovative drugs to treat overactive bladder.
Collapse
Affiliation(s)
| | | | - Massimo Lazzeri
- Department of Urology, Istituto Clinico Humanitas IRCCS, Clinical and Research Hospital, Rozzano, Milan, Italy
| | - Remo Guerrini
- Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Girolamo Caló
- Section of Pharmacology, Department of Medical Sciences, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy
| |
Collapse
|
2
|
Tariq S, Nurulain SM, Rashed H, Lotfy M, Emerald SB, Koturan S, Tekes K, Adeghate E. Diabetes-induced changes in the morphology and nociceptinergic innervation of the rat uterus. J Mol Histol 2016; 47:21-33. [PMID: 26589323 DOI: 10.1007/s10735-015-9643-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/08/2015] [Indexed: 10/22/2022]
Abstract
The prevalence of diabetes mellitus (DM) is about 6% across the globe. This prevalence has been reported to increase in the near future. This means that the number of women with DM who would like to get pregnant and have children will also increase. The present study is aimed at investigating the morphological changes observed in the uterus after the onset of DM. The study also examined the pattern of distribution of nociceptin (NC), a neuropeptide involved in the regulation of pain, a major physiological factor during parturition. The study shows a severe atrophy of uteri as early as 15 days post DM and continued until the termination of the eight-week study. This atrophy was confirmed by light microscopy. Electron microscopy study showed atrophy of the columnar cells of the endometrium, reduced myofibril number and destruction of smooth muscle cells in the myometrium of diabetic rats compared to control. Immunofluorescence and immunoelectron microscopy studies clearly demonstrated the presence of NC in the endometrium, myometrium and on the myofibrils of the smooth muscles of both control and diabetic rat uteri. In addition, NC-positive neurons and varicose fibres were observed in the myometrium of both normal and diabetic rats. However, the expression of NC decreased after the onset of DM. Morphometric analysis showed that the number of NC-labeled cells was significantly (p < 0.05) lower in diabetic rat uteri compared to those of control. In conclusion, DM-induced uterine atrophy is associated with a decrease in the expression of NC in cells, neurons and myofibrils of the rat uterus.
Collapse
Affiliation(s)
- Saeed Tariq
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Syed M Nurulain
- Department of Pharmacology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Hameed Rashed
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Mohamed Lotfy
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Starling Bright Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Surya Koturan
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Kornélia Tekes
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
| | - Ernest Adeghate
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates.
| |
Collapse
|
3
|
Calo’ G, Guerrini R. Medicinal Chemistry, Pharmacology, and Biological Actions of Peptide Ligands Selective for the Nociceptin/Orphanin FQ Receptor. ACS SYMPOSIUM SERIES 2013. [DOI: 10.1021/bk-2013-1131.ch015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Girolamo Calo’
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara and National Institute of Neuroscience, Italy
- Department of Pharmaceutical Sciences and LTTA (Laboratorio per le Tecnologie delle Terapie Avanzate), University of Ferrara, Italy
| | - Remo Guerrini
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara and National Institute of Neuroscience, Italy
- Department of Pharmaceutical Sciences and LTTA (Laboratorio per le Tecnologie delle Terapie Avanzate), University of Ferrara, Italy
| |
Collapse
|
4
|
Calo' G, Rizzi A, Cifani C, Micioni Di Bonaventura MV, Regoli D, Massi M, Salvadori S, Lambert DG, Guerrini R. UFP-112 a potent and long-lasting agonist selective for the Nociceptin/Orphanin FQ receptor. CNS Neurosci Ther 2010; 17:178-98. [PMID: 20497197 DOI: 10.1111/j.1755-5949.2009.00107.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nociceptin/orphanin FQ (N/OFQ) controls several biological functions via selective activation of the N/OFQ peptide receptor (NOP). [(pF)Phe(4) Aib(7) Arg(14) Lys(15) ]N/OFQ-NH(2) (UFP-112) is an NOP receptor ligand designed using a combination of several chemical modifications in the same peptide sequence that increase NOP receptor affinity/potency and/or reduce susceptibility to enzymatic degradation. In the present review article, we summarize data from the literature and present original findings on the in vitro and in vivo pharmacological features of UFP-112. Moreover, important biological actions and possible therapeutic indications of NOP receptor agonists are discussed based on the results obtained with UFP-112 and compared with other peptide and nonpeptide NOP receptor ligands.
Collapse
Affiliation(s)
- Girolamo Calo'
- Department Experimental and Clinical Medicine, Section of Pharmacology and Neuroscience Center, University of Ferrara, and National Institute of Neuroscience, Ferrara, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Basso M, Risse PA, Naline E, Calo G, Guerrini R, Regoli D, Advenier C. Nociceptin/orphanin FQ inhibits electrically induced contractions of the human bronchus via NOP receptor activation. Peptides 2005; 26:1492-6. [PMID: 16042989 DOI: 10.1016/j.peptides.2005.03.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nociceptin/orphanin FQ (N/OFQ) has been reported to inhibit neurogenic contractions in various tissues, including guinea pig airways. In the present study, we investigated the ability of N/OFQ to affect cholinergic contractions of human bronchi elicited by electrical field stimulation (EFS). Tissues were obtained from 23 patients undergoing surgery for lung cancer. EFS (20 Hz, 320 mA, 1.5 ms, 10 s) was applied five times every 20 min. Contractions induced by EFS were abolished by either TTX (1 microM) or atropine (1 microM) and concentration-dependently (10 nM-1 microM) inhibited by N/OFQ (Emax, 11.5+/-1.8% inhibition). The inhibitory effects of N/OFQ were mimicked by the N/OFQ receptor (NOP) ligand [Arg14, Lys15]N/OFQ which displayed however, higher significant maximal effects (17.7+/-2.9% inhibition, P<0.05). The actions of N/OFQ and [Arg14, Lys15]N/OFQ were not affected by naloxone (1 microM) while prevented by the selective NOP receptor antagonist UFP-101 (10 microM). Moreover, the inhibitory effects of NOP agonists were no longer evident in tissues treated with tertiapin (10 microM), an inhibitor of inward-rectifier potassium channels. In conclusion, the present data demonstrate that N/OFQ inhibited acetylcholine (ACh) release in the human bronchi via NOP receptor activation. This effect may involve stimulation of potassium currents.
Collapse
Affiliation(s)
- Marco Basso
- UPRES EA 220-Pharmacology, University of Versailles and UFR Biomédicale des Saint-Péres, 45 rue des Saints Péres, F-75006 Paris, France
| | | | | | | | | | | | | |
Collapse
|
6
|
D'Agostino B, Marrocco G, De Nardo M, Calò G, Guerrini R, Gallelli L, Advenier C, Rossi F. Activation of the nociceptin/orphanin FQ receptor reduces bronchoconstriction and microvascular leakage in a rabbit model of gastroesophageal reflux. Br J Pharmacol 2005; 144:813-20. [PMID: 15685213 PMCID: PMC1576063 DOI: 10.1038/sj.bjp.0706066] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 09/22/2004] [Accepted: 10/20/2004] [Indexed: 12/12/2022] Open
Abstract
1. Nociceptin/orphanin FQ (N/OFQ) is the endogenous peptide ligand for a specific G-protein coupled receptor, the N/OFQ peptide receptor (NOP). The N/OFQ-NOP receptor system has been reported to play an important role in pain, anxiety and appetite regulation. In airways, N/OFQ was found to inhibit the release of tachykinins and the bronchoconstriction and cough provoked by capsaicin. 2. Here we evaluated the effects of NOP receptor activation in bronchoconstriction and airway microvascular leakage induced by intraesophageal (i.oe.) hydrochloric acid (HCl) instillation in rabbits. We also tested the effects of NOP receptor activation in SP-induced plasma extravasation and bronchoconstriction. 3. In anesthetized New Zealand rabbits bronchopulmonary function (total lung resistance (R(L)) and dynamic compliance (C(dyn))) and airway microvascular leakage (extravasation of Evans blue dye) were evaluated. 4. Infusion of i.oe. HCl (1 N) led to a significant increase in bronchoconstriction and plasma extravasation in the main bronchi and trachea of rabbits pretreated with propranolol, atropine and phosphoramidon. 5. Bronchoconstriction and airway microvascular leakage were inhibited by N/OFQ (3-30 microg kg(-1) i.v.) in a dose-dependent manner. The NOP receptor agonist [Arg14,Lys15]N/OFQ mimicked the inhibitory effect of N/OFQ, being 10-fold more potent, UFP-101, a peptide selective NOP receptor antagonist, blocked the inhibitory effects of both agonists. 6. Under the same experimental conditions, N/OFQ and [Arg14,Lys15]N/OFQ did not counteract the bronchoconstriction and airway microvascular leakage induced by substance P. 7. These results suggest that bronchoconstriction and airway plasma extravasation induced by i.oe. HCl instillation are inhibited by activation of prejunctional NOP receptors.
Collapse
Affiliation(s)
- Bruno D'Agostino
- Department of Experimental Medicine-Section of Pharmacology, Faculty of Medicine and Surgery, 2nd University of Naples, via Constantinopoli 16, 80138 Naples, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
Neurogenic inflammation encompasses the release of neuropeptides from airway nerves leading to inflammatory effects. This neurogenic inflammatory response of the airways can be initiated by exogenous irritants such as cigarette smoke or gases and is characterized by a bi-directional linkage between airway nerves and airway inflammation. The event of neurogenic inflammation may participate in the development and progression of chronic inflammatory airway diseases such as allergic asthma or chronic obstructive pulmonary disease (COPD). The molecular mechanisms underlying neurogenic inflammation are orchestrated by a large number of neuropeptides including tachykinins such as substance P and neurokinin A, or calcitonin gene-related peptide. Also, other biologically active peptides such as neuropeptide tyrosine, vasoactive intestinal polypeptide or endogenous opioids may modulate the inflammatory response and recently, novel tachykinins such as virokinin and hemokinins were identified. Whereas the different aspects of neurogenic inflammation have been studied in detail in laboratory animal models, only little is known about the role of airway neurogenic inflammation in human diseases. However, different functional properties of airway nerves may be used as targets for future therapeutic strategies and recent clinical data indicates that novel dual receptor antagonists may be relevant new drugs for bronchial asthma or COPD.
Collapse
Affiliation(s)
- D A Groneberg
- Otto-Heubner-Centre, Pneumology and Immunology, Charité School of Medicine, Free University Berlin and Humboldt-University Berlin, Berlin, Germany
| | | | | | | |
Collapse
|
8
|
Faisy C, Naline E, Rouget C, Risse PA, Guerot E, Fagon JY, Chinet T, Roche N, Advenier C. Nociceptin inhibits vanilloid TRPV-1-mediated neurosensitization induced by fenoterol in human isolated bronchi. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2004; 370:167-75. [PMID: 15351928 DOI: 10.1007/s00210-004-0974-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2004] [Accepted: 07/22/2004] [Indexed: 01/25/2023]
Abstract
Chronic exposure to beta(2)-adrenoceptor agonists, especially fenoterol, has been shown to increase smooth muscle contraction to endothelin-1 in human bronchi partly through tachykinin-mediated pathways. The purpose of this work was to further investigate the role of sensory nerves in fenoterol-induced sensitization of human airways and the effect of nociceptin, a nociceptin/orphanin FQ (NOP) receptor agonist, on the increase in contraction after fenoterol exposure. Human bronchi from 62 patients were sensitized to endothelin-1 by prolonged incubation with fenoterol (0.1 microM, 15 h). The sensitizing effect of fenoterol was inhibited by high concentration of capsaicin (10 microM, 30 min before fenoterol sensitization), which induces depletion of mediators from sensory nerves, or co-incubation of fenoterol and capsazepine (1 microM), a vanilloid TRPV-1 receptor antagonist. Moreover, short pretreatment of bronchi with capsaicin (10 microM) or capsazepine (1 microM) after sensitization by fenoterol decreased the rise in smooth muscle contraction to endothelin-1. Nociceptin (1 microM) also inhibited the increased contraction in fenoterol-sensitized bronchi. Tertiapin (10 microM), an inhibitor of the inward-rectifier K(+) channels, but not naloxone (0.1 microM), a DOP/KOP/MOP receptor antagonist, prevented the inhibitory effect of nociceptin. In conclusion, fenoterol induces sensitization of human isolated bronchi to endothelin-1 in part through the stimulation of the vanilloid TRPV-1 receptor on tachykininergic sensory nerves. Nociceptin inhibits airway hyperresponsiveness via NOP receptor activation. This effect involves inward-rectifier K(+) channels.
Collapse
Affiliation(s)
- Christophe Faisy
- Unité de Recherche de l'Enseignement Supérieur, Equipe d'Accueil 220, Faculté de Médecine Paris-Ile de France-Ouest, Unité de Formation et de Recherche Biomédicale des Saint-Pères, 45 rue des Saint-Pères, 75006, Paris, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Lazzeri M, Calò G, Spinelli M, Guerrini R, Beneforti P, Sandri S, Zanollo A, Regoli D, Turini D. Urodynamic and clinical evidence of acute inhibitory effects of intravesical nociceptin/orphanin FQ on detrusor overactivity in humans: a pilot study. J Urol 2001. [PMID: 11696742 DOI: 10.1016/s0022-5347(05)65541-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PURPOSE Management of neurogenic incontinence is complex and available treatments are not satisfactory. Nociceptin/orphanin FQ, a recently discovered neuropeptide, has been reported to inhibit the voiding reflex in the rat. These experimental results prompted us to investigate the urodynamic and clinical effects of intravesical instillation of nociceptin/orphanin FQ in humans. MATERIAL AND METHODS Our study involved 5 normal subjects (group 1) with a mean age of 40.4 years (range 21 to 54) and 9 patients (group 2) 40.4 years (24 to 54). All patients in group 2 presented with detrusor hyperreflexia refractory to standard therapy. They were invited to undergo a filling cystometrogram with saline solution and after 30 minutes, a new one with a solution containing 1 microM. nociceptin/orphanin FQ. The urodynamic parameters that were recorded included bladder capacity, volume threshold for the appearance of detrusor hyperreflexia and maximum bladder pressure. Clinical and urodynamic followup was performed after 15 days. The data were statistically analyzed with 1-way analysis of variance followed by the Dunnett test for multiple comparison considered statistically significant with p <0.05. RESULTS Intravesical instillation of 1 microM. nociceptin/orphanin FQ in group 1 did not produce significant functional changes. This infusion in group 2 produced a statistically significant increase in mean bladder capacity and volume threshold for the appearance of detrusor hyperreflexia from 164 plus or minus standard deviation (SD) 84 to 301 +/- 118 and 93 plus or minus SD 41 to 231 +/- 104 ml. (p <0.05, respectively). Mean maximum bladder pressure decreased from 79 plus or minus SD 25 to 54 +/- 44 cm. water but was not statistically significant (p = 0.19). After 15 days an absence of clinical improvement was noticed in group 2, and the urodynamic control did not show any significant changes compared to the values before nociceptin/orphanin FQ treatment. No severe symptomatic reactions were observed during infusion of 1 microM. nociceptin/orphanin FQ. CONCLUSIONS Our results demonstrate that nociceptin/orphanin FQ is able to elicit a robust inhibitory effect on voiding reflex in group 2 but not 1. The ideal dosage, route of administration of nociceptin/orphanin FQ and treatment interval are not yet established.
Collapse
Affiliation(s)
- M Lazzeri
- Department of Urology, University of Ferrara, Ferrara, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
URODYNAMIC AND CLINICAL EVIDENCE OF ACUTE INHIBITORY EFFECTS OF INTRAVESICAL NOCICEPTIN/ORPHANIN FQ ON DETRUSOR OVERACTIVITY IN HUMANS:. J Urol 2001. [DOI: 10.1097/00005392-200112000-00047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
11
|
Mason SL, Ho M, Nicholson J, McKnight AT. In vitro characterization of Ac-RYYRWK-NH(2), Ac-RYYRIK-NH(2) and [Phe1Psi(CH(2)-NH)Gly2] nociceptin(1-13)NH(2) at rat native and recombinant ORL(1) receptors. Neuropeptides 2001; 35:244-56. [PMID: 12030809 DOI: 10.1054/npep.2001.0882] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The pharmacology of ORL(1) compounds, [Phe1Psi(CH(2)-NH)Gly2]nociceptin(1-13)NH(2) (F/GNC13), Ac-RYYRIK-NH(2) and Ac-RYYRWK-NH(2) was evaluated at rat ORL(1) receptors in frontal cortex (CTX), transfected chinese hamster ovary (CHO) cells, vas deferens (VD) and anococcygeus (AC). Ranked affinities for the inhibition of [3H]nociceptin binding to CTX and CHO's were: Ac-RYYRWK-NH(2) identical withAc-RYYRIK-NH(2) identical withnociceptin>F/GNC13>Dynorphin A>naloxone. The full agonist, nociceptin stimulated [35S]GTPgammaS binding in CTX (E(max)=174%) and CHO's (E(max)=311%); all other ORL(1) peptides acted as partial agonists with the following rank order for E(max) values: Ac-RYYRWK-NH(2) (96% (CTX), 202% (CHO))>F/GNC13 (44% (CTX), 136% (CHO)) identical withAc-RYYRIK-NH(2) (44% (CTX), 115% (CHO)). Schild analysis generated pA(2) values in CTX of 8.59 (F/GNC13) and 9.13 (Ac-RYYRIK-NH(2)). cAMP production in CHO's was inhibited by 77% (nociceptin), 58% (Ac-RYYRWK-NH(2)), 55% (F/GNC13) and 49% (Ac-RYYRIK-NH(2)). Nociceptin inhibited electrically evoked contractions in isolated tissues by 95% (VD) and 98% (AC); partial inhibition was observed with Ac-RYYRWK-NH(2) (72% (VD), 66% (AC)) and Ac-RYYRIK-NH(2) (54% (VD); 37%(AC)). Ineffective in the VD, F/GNC13 caused a small inhibition in the AC that was reversed at higher concentrations. Schild analysis gave pA(2) affinities of 7.32(VD) and 7.34(AC) for F/GNC13 and 8.69(AC) for Ac-RYYRIK-NH(2).
Collapse
Affiliation(s)
- S L Mason
- Pfizer Global Research and Development, Cambridge University Forvie Site, Robinson Way, Cambridge, CB2 2QB, UK.
| | | | | | | |
Collapse
|
12
|
Abstract
Changes in airway innervation are believed to play a key role in the pathophysiology of asthma. A group of regulatory peptides which act as neuroregulators is resembled by the opioids. Their localization to neurons projecting into airways suggested a possible role as regulators of neurogenic inflammation, bronchoconstriction and mucus secretion. They mainly act through modification of tachykinergic and cholinergic impulses and their ability to inhibit bronchoconstriction prompted discussion of their potential value in asthma therapy. Apart from the presence of the classical opioids and their receptors in the lung and their functional role, a new group of peptides such as nociceptin and endomorphins have been characterized in the airways. Whereas at least endomorphin-1 acts via the classical OP(3) (mu) receptor, nociceptin binds to a new receptor termed opioid receptor-like-receptor (ORL(1)) and inhibits tachykinergic constriction. Contrary to these promising modulatory effects on airway smooth muscle tone, effective therapeutic strategies have not been developed yet. In conclusion, opioids resemble a group of regulatory peptides which are present within airway-innervating nerve fibres and influence a multitude of airway functions via modification of neural transmission.
Collapse
Affiliation(s)
- D A Groneberg
- Division of Allergy Research, Department of Pediatric Pneumology and Immunology, Humboldt-University, Berlin, Germany.
| | | |
Collapse
|
13
|
Sugimori S, Kadowaki M, Yoneda S, Yamanouchi M, Nakano H, Takaki M. Nociceptin inhibits capsaicin-sensitive contraction to mesenteric nerve stimulation in the guinea-pig isolated ileum. Auton Neurosci 2000; 86:65-9. [PMID: 11269926 DOI: 10.1016/s1566-0702(00)00235-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Mesenteric nerve stimulation (MNS) in the presence of guanethidine and hexamethonium antidromically stimulated extrinsic sensory nerve fibers and cholinergic myenteric motor neurons, resulting in longitudinal muscle contraction in the isolated guinea-pig ileum. Nociceptin (NC) is a recently discovered neuropeptide that structurally resembles an opioid peptide. The aim of the current study was to examine how NC affects the contractile responses to MNS in the isolated guinea-pig ileum, in comparison with an opiate, methionine-enkephalin. These contractions were auxotonically recorded and their amplitude was analyzed. NC (1-100 nM) and methionine-enkephalin (0.1-10 microM) concentration-dependently inhibited the response to MNS (20 Hz, 0.5 ms, supramaximal currents). Naloxone (10 microM) significantly diminished the inhibitory effect of methionine-enkephalin (0.1-10 microM), but did not antagonize the inhibitory effect of NC (1-100 nM). We conclude that NC receptors, distinct from opioid receptors, exist on the capsaicin-sensitive sensory nerve fibers and/or myenteric cholinergic motor neurons in the guinea-pig ileum and that specific antagonists for these NC receptors are not found yet.
Collapse
Affiliation(s)
- S Sugimori
- Department of Physiology II, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan
| | | | | | | | | | | |
Collapse
|
14
|
Guerrini R, Caló G, Bigoni R, Rizzi A, Varani K, Toth G, Gessi S, Hashiba E, Hashimoto Y, Lambert DG, Borea PA, Tomatis R, Salvadori S, Regoli D. Further studies on nociceptin-related peptides: discovery of a new chemical template with antagonist activity on the nociceptin receptor. J Med Chem 2000; 43:2805-13. [PMID: 10956188 DOI: 10.1021/jm990075h] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three series of nociceptin (NC)-related peptides were synthesized and their abilities (i) to bind to the NC sites expressed in mouse forebrain membranes, (ii) to inhibit the electrically evoked contraction of the mouse vas deferens, and (iii) to inhibit forskolin-stimulated cAMP accumulation in Chinese hamster ovary cells expressing the human recombinant NC receptor (CHONCR) were investigated. The compounds of the first series (a series) have an ordinary Xaa1-Gly2 bond, those of the second series (b series) have a Xaa1psi(CH2-NH)Gly2 pseudopeptide bond, and those of the third series (c series) have a peptoid (Nxaa1-Gly2) structure. The affinity values measured in the binding assay and in the two functional assays with the compounds of the three series showed high levels of correlation. Thus, (I) the compounds of the a series in which Phe1 was substituted with Tyr, Cha, or Leu acted as potent NC receptor agonists; (II) the b series compounds behaved as NC receptor antagonists in the mouse vas deferens and as full agonists in CHO(NCR) cells with different potencies depending on the first amino acid residue, [Phe1psi(CH2-NH)Gly2]NC(1-17)NH2 and [Phe1psi(CH2-NH)Gly2]NC(1-13)NH2 being the most potent compounds; (III) the compounds of the third series were all inactive both as agonists and as antagonists with the exception of [Nphe1]NC(1-17)NH2 and [Nphe1]NC(1-13)NH2, which behaved as NC receptor antagonists both in the isolated tissue and in CHO(NCR) cells (pKB 6.1-6.4). In conclusion, this study demonstrates that chemical requirements for NC receptor agonists are different from those of antagonists. Moreover, modifications of the steric orientation of the aromatic residue Phe1 in the NC sequence as obtained with the pseudopeptide bond between Phe1 and Gly2 or with the displacement of the benzyl side chain by one atom, as in Nphe1, lead respectively to reduction or elimination of efficacy. Indeed, in contrast to [Phe1psi(CH2-NH)Gly2]NC(1-13)NH2 which has been reported to exhibit agonist activity in several assays involving either central or recombinant NC receptors, [Nphe1]NC(1-13)NH2 antagonizes the effect of NC at human recombinant NC receptors and in the mouse tail withdrawal assay.
Collapse
Affiliation(s)
- R Guerrini
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
Nociceptin (NC), alias Orphanin FQ (OFQ) is a heptadecapeptide structurally related to opioid peptides, especially Dynorphin A, which, however, does not interact with classic opioid receptors. NC selectively activates its own receptor (OP(4)), which has been shown to be insensitive to the naturally occurring opioid peptides as well as to a large number of non-peptide opioid receptor ligands, including naloxone. Thus, the NC/OP(4) system represents a new peptide-based signaling pathway, which is pharmacologically distinct from the opioid systems. The pharmacological tools available for investigating NC actions are at present rather limited and include: 1) peptide ligands obtained from structure activity studies performed using NC(1-13)NH(2) as a template or discovered by screening peptide combinatorial libraries; 2) nonpeptide ligands that are either molecules already known to interact with classic opioid receptors or novel molecules designed and synthesized as selective ligands of the OP(4) receptor. In the present paper the functional data obtained from both in vitro and in vivo studies with each relevant OP(4) receptor ligand will be analyzed and discussed comparing the advantages and disadvantages of each molecule. We hope that the present work will aid investigators, working in the NC/OP(4) field, in the choice of the pharmacological tools suitable for their experiments.
Collapse
Affiliation(s)
- G Calo'
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferarra, via Fossato di Mortara 17/19, 44-100, Ferrara, Italy.
| | | | | | | | | | | |
Collapse
|
16
|
Abstract
Nociceptin exerts a general modulatory effect on transmitter release from sympathetic, parasympathetic, NANC and sensory nerve endings in the peripheral nervous system in various species. This effect occurs at a prejunctional level and is independent from the activation of mu, delta and kappa opioid receptors. Despite the growing evidence describing the peripheral activity of nociceptin since its discovery in 1995, the lack of selective and potent antagonists does not allow us to draw conclusions on the putative physiological role of this peptide at this level.
Collapse
Affiliation(s)
- S Giuliani
- Pharmacology Department, Menarini Ricerche S.p.A., Via Rismondo 12A, 50131, Florence, Italy.
| | | | | |
Collapse
|
17
|
Abstract
The opioid-like heptadecapeptide nociceptin (NC) has the following effects in the airways (investigated in isolated tracheae and bronchi from guinea pig or rat): the electric field stimulation (EFS)-induces release of acetylcholine (ACh), the tachykinin substance P (SP) and calcitonin gene-related peptide (CGRP) is reduced after pretreatment with NC, and EFS-induced tachykinergic nonadrenergic-noncholinergic (NANC) bronchoconstriction is inhibited by NC. Both the NC-mediated inhibition of neurotransmission and of smooth muscle contraction occurred in a concentration-dependent manner. Because these effects were naloxone-insensitive, were blocked by the NC receptor antagonist [F/G]NC(1-13)NH(2), and could be mimicked by the NC analogs, NCNH(2) and NC(1-13)NH(2), it is thought that they are distinct from the classic opioid receptors. That these pharmacological actions of NC are of relevance for airway physiology is highly probable given the presence of NC-immunoreactivity in the nerve fibers of the airways and of opioid-like receptor (ORL-1) transcripts in the jugular ganglia, from where the tachykinin-containing afferents arise.
Collapse
Affiliation(s)
- C Peiser
- Humboldt University, Charité, Virchow Clinic, Department of Pediatric Pneumology and Immunology, Berlin, Germany.
| | | | | |
Collapse
|
18
|
Abstract
The ORL1 receptor is a G protein-coupled receptor structurally related to the opioid receptors, whose endogenous ligand is the heptadecapeptide nociceptin/orphanin FQ. In this review, data which have contributed to the mapping of the anatomic distribution of the ORL1 receptor have been collated with an emphasis on their relation to physiological functions. The ORL1 receptor is widely expressed in the central nervous system, in particular in the forebrain (cortical areas, olfactory regions, limbic structures, thalamus), throughout the brainstem (central periaqueductal gray, substantia nigra, several sensory and motor nuclei), and in both the dorsal and ventral horns of the spinal cord. Regions almost devoid of ORL1 receptors are the caudate-putamen and the cerebellum. ORL1 mRNA and binding sites exhibit approximately the same distribution pattern, indicating that the ORL1 receptor is located on local neuronal circuits. The ORL1 receptor is also expressed at the periphery in smooth muscles, peripheral ganglia, and the immune system. The anatomic distribution of ORL1 receptor suggests a broad spectrum of action for the nociceptin/orphanin FQ system (sensory perception, memory process, emotional behavior, etc.).
Collapse
Affiliation(s)
- C Mollereau
- Institut de Pharmacologie et Biologie Structurale, 205 route de Narbonne, 31077, Toulouse, France.
| | | |
Collapse
|
19
|
Pheng LH, Calo G, Guerrini R, Regoli D. [Nphe(1)]nociceptin-(1-13)NH(2) selectively antagonizes nociceptin effects in the rabbit isolated ileum. Eur J Pharmacol 2000; 397:383-8. [PMID: 10844138 DOI: 10.1016/s0014-2999(00)00300-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
When suspended in vitro in isolated organ baths, segments of the rabbit ileum show a fairly strong and stable spontaneous activity, which derives from the continuous release of acetylcholine and the activation of muscarinic receptors, since the activity is completely eliminated by atropine. Dynorphin A (pEC(50): 8.6+/-0.07), neuropeptide Y and its congener human pancreatic polypeptide (pEC(50): 9.40+/-0.10), and nociceptin (pEC(50): 8.08+/-0.12) dose-dependently inhibit the spontaneous activity through the activation of receptors, which are specifically antagonised respectively by naloxone (pA(2): 7.17+/-0.12), 2-(naphtalen-1-ylamino)-3-phenylpropionitrile (JCF 104; pA(2): 5. 80+/-0.10), and [Nphe(1)]nociceptin-(1-13)NH(2) (pA(2): 6.17+/-0.19). This last compound, a selective nociceptin-receptor (OP(4)) antagonist, inhibits the effect of nociceptin in a competitive manner, as demonstrated by Schild analysis. [Nphe(1)]nociceptin-(1-13)NH(2) also antagonizes the effects of other OP(4) receptor ligands such as the full agonist, nociceptin-(1-13)-NH(2), and the partial agonists, [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin-(1-13)-NH(2) (intrinsic activity (alpha(E))=0.5) and Ac-RYYWK-NH(2) (alpha(E)=0.5), with pA(2) values ranged from 5.8 to 6.2. These results indicate that the functional site mediating the inhibitory effect of nociceptin in the rabbit ileum, is pharmacologically identical to the OP(4) sites of other species (mouse, rat, guinea pig, man), since the potencies (pA(2) values) of the pure and competitive antagonist [Nphe(1)]nociceptin-(1-13)NH(2) is very similar to the values obtained in the other species. Moreover, the rabbit ileum is one of the few isolated organs that allow classifying compounds, which interact with OP(4) receptors as full agonists, partial agonists, or pure antagonists.
Collapse
Affiliation(s)
- L H Pheng
- Institute of Pharmacology of Sherbrooke, Universtity of Sherbrooke, 3001, 12e Avenue Nord, J1H 5N4, Sherbrooke, Quebec, Canada
| | | | | | | |
Collapse
|
20
|
Chiou LC. Pharmacological characterization of the nociceptin receptor, ORL1. Insight from the inward rectifier activation in the periaqueductal gray. J Biomed Sci 2000; 7:232-40. [PMID: 10810242 DOI: 10.1007/bf02255471] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
A novel opioid receptor-like orphan receptor (ORL1) was cloned and identified to be homologous to classical opioid receptors but insensitive to traditional opioids. A heptadecapeptide, termed orphanin FQ or nociceptin (OFQ/N), was identified as its endogenous ligand. OFQ/N shares overlapping distribution sites in pain-processing areas and common cellular mechanisms with opioids but exerts diverse effects on nociceptive responses. Of the two reported ORL1 antagonists, [Phe(1)psi(CH(2)-NH)- Gly(2)] nociceptin-(1-13)-NH(2) (Phepsi) and naloxone benzoylhydrazone (NBZ), antagonisms were validated in the activation of inward rectifying K channels induced by OFQ/N, using the patch clamp technique in ventrolateral periaqueductal gray slices. Results showed that Phepsi acted as a partial agonist and NBZ was a weak nonselective antagonist of ORL1. It is comparable with most but not all of the findings from other tissues. Comparing all the reports supports the above inference for these two antagonists. The possible causes for the discrepancy were discussed. A brief review on the putative ORL1 antagonists, acetyl-RYYRIK-NH2, some sigma-ligands and the functional antagonist, nocistatin, is also included. It indicates that a potent and selective ORL1 antagonist is expecting to elucidate the physiological role of OFQ/N.
Collapse
Affiliation(s)
- L C Chiou
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
21
|
Calo' G, Guerrini R, Rizzi A, Salvadori S, Regoli D. Pharmacology of nociceptin and its receptor: a novel therapeutic target. Br J Pharmacol 2000; 129:1261-83. [PMID: 10742280 PMCID: PMC1571975 DOI: 10.1038/sj.bjp.0703219] [Citation(s) in RCA: 342] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/1999] [Revised: 01/05/2000] [Accepted: 01/10/2000] [Indexed: 12/13/2022] Open
Abstract
Nociceptin (NC), alias Orphanin FQ, has been recently identified as the endogenous ligand of the opioid receptor-like 1 receptor (OP(4)). This new NC/OP(4) receptor system belongs to the opioid family and has been characterized pharmacologically with functional and binding assays on native (mouse, rat, guinea-pig) and recombinant (human) receptors, by using specific and selective agonists (NC, NC(1 - 13)NH(2)) and a pure and competitive antagonist, [Nphe(1)]NC(1 - 13)NH(2). The similar order of potency of agonists and affinity values of the antagonist indicate that the same receptor is present in the four species. OP(4) is expressed in neurons, where it reduces activation of adenylyl cyclase and Ca(2+) channels while activating K(+) channels in a manner similar to opioids. In this way, OP(4) mediates inhibitory effects in the autonomic nervous system, but its activities in the central nervous system can be either similar or opposite to those of opioids. In vivo experiments have demonstrated that NC modulates a variety of biological functions ranging from nociception to food intake, from memory processes to cardiovascular and renal functions, from spontaneous locomotor activity to gastrointestinal motility, from anxiety to the control of neurotransmitter release at peripheral and central sites. These actions have been demonstrated using NC and various pharmacological tools, as antisense oligonucleotides targeting OP(4) or the peptide precursor genes, antibodies against NC, an OP(4) receptor selective antagonist and with data obtained from animals in which the receptor or the peptide precursor genes were knocked out. These new advances have contributed to better understanding of the pathophysiological role of the NC/OP(4) system, and ultimately will help to identify the therapeutic potential of new OP(4) receptor ligands.
Collapse
Affiliation(s)
- Girolamo Calo'
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17, 41100 Ferrara, Italy
| | - Remo Guerrini
- Department of Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara 17, 4100 Ferrara, Italy
| | - Anna Rizzi
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17, 41100 Ferrara, Italy
| | - Severo Salvadori
- Department of Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara 17, 4100 Ferrara, Italy
| | - Domenico Regoli
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17, 41100 Ferrara, Italy
| |
Collapse
|
22
|
Menzies JR, Glen T, Davies MR, Paterson SJ, Corbett AD. In vitro agonist effects of nociceptin and [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) in the mouse and rat colon and the mouse vas deferens. Eur J Pharmacol 1999; 385:217-23. [PMID: 10607879 DOI: 10.1016/s0014-2999(99)00700-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nociceptin is an endogenous ligand of the opioid receptor-like (ORL1) receptor, a G-protein coupled receptor with sequence similarities to the opioid receptors. ORL1 receptors are present at both central and peripheral sites in several mammalian species but their functions are as yet poorly understood. The main aim of this investigation was to study the effects of nociceptin and the putative ORL1 receptor antagonist [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) in two peripheral tissues, the isolated proximal colon of the mouse and the distal colon of the rat. Nociceptin, [D-Ala(2), MePhe(4), Gly-ol(5)]enkephalin (DAMGO; mu-opioid receptor selective) and [D-Pen(2), D-Pen(5)]enkephalin (DPDPE; delta-opioid receptor selective) caused concentration-dependent contractions of mouse and rat isolated colon preparations (nociceptin EC(50)=1.20 and 0.28 nM in the mouse and rat, respectively). Des[Phe(1)]nociceptin (250 nM) had no contractile effect. Naloxone (300 nM) antagonised the effects of DAMGO and DPDPE but had no effect in either preparation on contractions seen in response to nociceptin. [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) also caused contractions in the colonic preparations (EC(50)=6.0 and 3.1 nM in the mouse and rat, respectively); there was no evidence of any antagonist activity. Tetrodotoxin (1 microM) abolished the contractile effects of nociceptin in the mouse colon but had no effect in the rat. In the vas deferens preparation isolated from DBA/2 mice, nociceptin caused concentration-dependent inhibitions of electrically-evoked contractions which were antagonised by [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) (apparent pK(B)=6. 31). However, [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) (0.3-10 microM) also possessed agonist activity in this preparation, as it inhibited the electrically-evoked contractions in a concentration-dependent manner. These observations do not support the proposal that [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) has agonist activity at central ORL1 receptors but is an antagonist in the periphery and that these differences in efficacy point to differences in the receptors. Rather, these data along with those of others suggest that [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) is a partial agonist and that differences in receptor reserve can account for the varied pharmacological actions of this pseudopeptide at central and peripheral sites.
Collapse
MESH Headings
- Animals
- Benzeneacetamides
- Benzofurans/pharmacology
- Colon/drug effects
- Colon/physiology
- Dose-Response Relationship, Drug
- Electric Stimulation
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- In Vitro Techniques
- Ligands
- Male
- Mice
- Mice, Inbred DBA
- Muscle Contraction/drug effects
- Narcotic Antagonists
- Opioid Peptides/pharmacology
- Peptide Fragments/pharmacology
- Pyrrolidines/pharmacology
- Rats
- Rats, Wistar
- Receptors, Opioid/agonists
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, mu/agonists
- Tetrodotoxin/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
- Nociceptin Receptor
- Nociceptin
Collapse
Affiliation(s)
- J R Menzies
- School of Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, UK
| | | | | | | | | |
Collapse
|
23
|
Salvadori S, Guerrini R, Calo G, Regoli D. Structure-activity studies on nociceptin/orphanin FQ: from full agonist, to partial agonist, to pure antagonist. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 1999; 54:810-25. [PMID: 10668183 DOI: 10.1016/s0014-827x(99)00108-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A heptadecapeptide (Phe-Gly-Gly-Phe-Thr-Gly-Ala-Arg-Lys-Ser-Ala-Arg-Lys-Leu-Ala-Asn-Gln) was identified from rat brain and from porcine brain as a ligand for OP4, a new G-protein coupled receptor that is similar in sequence to opioid receptors. The OP4 receptor is widely expressed in the nervous system where it mediates a broad range of physiological functions. The new peptide, nociceptin (NC), has a primary sequence recalling that of opioid peptides. Despite the homologies (a) of the OP4 receptor with known opioid receptors, especially the OP2 (kappa) receptor, and (b) of NC with opioid peptides, particularly dynorphin A, the two biological systems have different anatomical locations and chemical requirements for activation. NC does not bind to opioid receptors, and mammalian opioid peptides do not interact with the OP4 receptor. The presence of Phe in position 1 and Arg in position 8, appear to be instrumental to exclude NC from interacting with the opioid receptors. Contrary to opioid peptides which strikly require Tyr in position 1, the active core that activates the OP4 appears to be towards the centre of the peptide molecule and includes Phe4. Based on the message/address model, several changes have been made in the N-terminal tetrapeptide Phe-Gly-Gly-Phe (message) and a few also in the C-terminal of the template NC(1-13)-NH2, a fragment that acts as a full agonist both in vitro and in vivo. Subtle changes of the N-terminal sequence, especially at Phe1, led to the discovery of peptide antagonists ([Phe1 psi (CH2-NH)Gly2[-NC(1-13)-NH2 and [Nphe1[-NC(1-13)-NH2). The first compound has been widely used to characterize NC actions in the periphery and in the central nervous system. It has been shown to act mainly as an antagonist outside the brain and as an agonist in the central nervous system. [Nphe1[-NC(1-13)-NH2- on the contrary, acts as antagonist both in the periphery and in the brain. These first peptide prototypes may soon be followed by non-peptide compounds, some of which, are already described in patient literature.
Collapse
Affiliation(s)
- S Salvadori
- Department of Pharmaceutical Sciences, University of Ferrara, Italy.
| | | | | | | |
Collapse
|
24
|
Bertorelli R, Corradini L, Rafiq K, Tupper J, Calò G, Ongini E. Nociceptin and the ORL-1 ligand [Phe1psi (CH2-NH)Gly2]nociceptin(1-13)NH2 exert anti-opioid effects in the Freund's adjuvant-induced arthritic rat model of chronic pain. Br J Pharmacol 1999; 128:1252-8. [PMID: 10578139 PMCID: PMC1571738 DOI: 10.1038/sj.bjp.0702884] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/1999] [Revised: 08/06/1999] [Accepted: 08/16/1999] [Indexed: 11/09/2022] Open
Abstract
1 Stimulation of the opioid receptor-like1 (ORL-1) receptor by nociceptin (NC) produces hyperalgesia and reverses the antinociceptive effects induced by opioids. Most studies concerning the central effects of NC were conducted using acute pain models. The role NC may play in chronic inflammation remains unelucidated. 2 The present study was undertaken to assess the action of NC in the Freund's adjuvant-induced monoarthritic rat model. The effects of drugs known to act as analgesics in this model were evaluated. The effects of NC, NCNH2, and the ORL-1 ligand, [Phe1psi(CH2-NH)Gly2]NC(1-13)NH2 ([F/G]NC(1-13)NH2), were also studied alone or in association with morphine. 3 NC (1 - 30 nmol, i. c.v.) was inactive, whilst NCNH2 (10 nmol, i.c.v.) exerted hyperalgesic effects (-4.5+/-0.9 vs -0.7+/-0.8 s of vehicle-treated animals). [F/G]NC(1-13)NH2 (0.01 - 10 nmol, i.c.v.) induced hyperalgesia in the arthritic paw (-3.3+/-0.6 vs -0.3+/-0.5 s of vehicle-treated animals; 10 nmol). 4 Both NC (0.01 - 10 nmol, i.c.v. ) and [F/G]NC(1-13)NH2 (0.01 - 1 nmol, i.c.v), 30 min after morphine (3 mg kg-1, s.c.) induced an immediate and short-lived reversal of morphine effects (2.6+/-0.3 vs 10.4+/-1.0 and 1.2+/-1.5 vs 9.3+/-1.1 s of morphine alone, respectively), therefore displaying anti-opioid activity. 5 In the Freund's adjuvant-induced rat model of arthritis, both NC and [F/G]NC(1-13)NH2 act as anti-opioid peptides. Furthermore, NCNH2 and [F/G]NC(1-13)NH2 induce hyperalgesia when given alone. Further investigations and the identification of a centrally acting ORL-1 antagonist are necessary to better understand the role of NC in pain mechanisms.
Collapse
Affiliation(s)
- R Bertorelli
- Schering-Plough Research Institute, San Raffaele Science Park, Via Olgettina, 58, 20132 Milan, Italy.
| | | | | | | | | | | |
Collapse
|