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Adeghate E, Saeed Z, D'Souza C, Tariq S, Kalász H, Tekes K, Adeghate EA. Effect of nociceptin on insulin release in normal and diabetic rat pancreas. Cell Tissue Res 2018; 374:517-529. [PMID: 30112574 DOI: 10.1007/s00441-018-2903-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 07/25/2018] [Indexed: 01/08/2023]
Abstract
Nociceptin (NC), also known as Orphanin FQ, is a brain peptide involved in the regulation of pain, but its role in the endocrine pancreas is poorly understood. The present study examines the pattern of distribution of NC and its effect on insulin and glucagon secretion after the onset of diabetes mellitus (DM). Male Wistar rats weighing 150-200 g were made diabetic with streptozotocin (60 mg/kg body weight, intraperitoneally). Four weeks after the induction of DM, pancreatic tissues were retrieved and processed for immunofluorescence, immunoelectron microscopy, and insulin and glucagon secretion. Isolated islets from non-diabetic and diabetic rats were used to determine the effect of NC on insulin release. NC was discerned in islet cells of non-diabetic control and diabetic rat pancreata. NC co-localized only with insulin in pancreatic beta cells. NC did not co-localize with either glucagon or somatostatin or pancreatic polypeptide. The number of NC-positive cells was markedly (p < 0.001) reduced after the onset of DM. Electron microscopy study showed that NC is located with insulin in the same secretory granules of the beta cells of both non-diabetic and diabetic rat pancreas. NC inhibits insulin release markedly (p < 0.05) from pancreatic tissue fragments of non-diabetic and diabetic rats. In contrast, NC at 10-12 M stimulates insulin release in isolated islets of DM rats. In conclusion, NC co-localizes with insulin only in the islet of Langerhans. The co-localization of NC with insulin suggests a role for NC in the regulation of pancreatic beta cell function.
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Affiliation(s)
- Ernest Adeghate
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | | | - Crystal D'Souza
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Saeed Tariq
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates
| | - Huba Kalász
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Kornélia Tekes
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
| | - Ernest A Adeghate
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates.
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β1/2 or M2/3 Receptors Are Required for Different Gastrointestinal Motility Responses Induced by Acupuncture at Heterotopic or Homotopic Acupoints. PLoS One 2016; 11:e0168200. [PMID: 27978539 PMCID: PMC5158317 DOI: 10.1371/journal.pone.0168200] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 11/04/2016] [Indexed: 12/14/2022] Open
Abstract
Acupuncture at homotopic acupoints or heterotopic acupoints is known to either inhibit or facilitate gastrointestinal motility, depending on the acupoint location. However, little effort has been made to investigate the roles of specific receptors (such as adrenergic and muscarinic acetylcholine receptors) in mediating the effects of acupuncture at heterotopic and homotopic acupoints. Different adrenergic receptor subtypes or cholinergic receptor subtypes are predominantly expressed in various sections of the gut, resulting in variations between the effects of acupuncture at heterotopic or homotopic acupoints on gastrointestinal motility. Here, we investigated the role of β1/β2 receptors and M2/M3 receptors in gastrointestinal motility regulated by acupuncture at ST37, a heterotopic acupoint, and ST25, a homotopic acupoint, by simultaneously recording intraluminal pressures in the distal colon and stomach or jejunum and examining fecal phenol red excretion in β1/2 receptor-knockout mice and M2/3 receptor-knockout mice. We found that knockout of the M2/3 receptor significantly inhibited ST37 acupuncture-induced enhancement of gastric motility, jejunal motility, and colonic motility. Additionally, knocking out of the β1/2 receptor significantly diminished the ST25 acupuncture-induced inhibition of gastric motility and jejunal motility without significantly altering the enhancement of colonic motility induced by acupuncture at ST25. Acupuncture at ST37 significantly accelerated gastrointestinal transition in β1/2 receptor-knockout mice and their wild-type littermates. However, this acceleration of gastrointestinal transition was markedly diminished in M2/3 receptor-knockout mice relative to their wild-type littermates. Acupuncture at ST25 significantly increased gastrointestinal transition in β1/2 receptor-knockout mice and significantly decreased gastrointestinal transition in M2/3 receptor-knockout mice without altering gastrointestinal transition in wild-type littermates of either. Our study revealed that M2/3 receptors are required for the gastrointestinal motility associated with whole gastrointestinal transition enhanced by acupuncture at heterotopic acupoints, whereas β1/2 receptors are required for the same gastrointestinal motility processes inhibited by acupuncture at homotopic acupoints. Therefore, our findings reveal important biological mechanisms underlying acupuncture treatment of disorders involving gastrointestinal motility dysfunction.
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Agostini S, Petrella C. The endogenous nociceptin/orphanin FQ-NOP receptor system as a potential therapeutic target for intestinal disorders. Neurogastroenterol Motil 2014; 26:1519-26. [PMID: 25307525 DOI: 10.1111/nmo.12460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 09/19/2014] [Indexed: 12/30/2022]
Abstract
In 1995, by reverse pharmacology approach, used here for the first time in the history of pharmacology, nociceptin/orphanin FQ (N/OFQ) has been discovered as the endogenous ligand of a preidentified receptor named opioid receptor like 1. Subsequent studies showed that N/OFQ and its receptor (N/OFQergic system) are widely distributed in central and peripheral nervous systems as well as in peripheral organs of human and animals, and represent a system that is involved in a very large range of biological functions such as pain perception, intestinal motility and secretion, immune modulation, stress. From the time of its discovery to now, a high number of NOP agonists and antagonists have been synthesized and tested in various pathologies. Nevertheless, none of the molecules targeting N/OFQergic system have currently succeeded in going through clinical trials concerning gut pathologies, indicating that further studies are required. The work from Dr. Fichna et al., published in the present issue of Neurogastroenterology and Motility, adds another brick in the wall of understanding the role of N/OFQergic system in IBS-D pathology by the pharmacological evaluation of a new NOP receptor agonist, SCH 221510, in animal models of intestinal alterations (diarrhea and visceral hyperalgesia). Interestingly, authors report clinical data confirming the involvement of N/OFQergic system in IBS-D patients and, consequently, suggest this system as a valuable therapeutic target for IBS-D pathology. This minireview aims to give a brief summary of experimental and clinical studies focusing on the N/OFQergic system as pharmacological target for the therapeutic treatment of intestinal pathologies such as IBS and IBD.
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Affiliation(s)
- S Agostini
- INRA, EI-Purpan, UMR1331 Toxalim, Group of Neuro-Gastroenterology and Nutrition, Toulouse, France
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Petrella C, Giuli C, Broccardo M, Eutamene H, Cartier C, Leveque M, Bedini A, Spampinato S, Bueno L, Theodorou V, Improta G, Agostini S. Protective and worsening peripheral nociceptin/orphanin FQ receptor-mediated effect in a rat model of experimental colitis. Pharmacol Res 2013; 70:72-9. [PMID: 23353033 DOI: 10.1016/j.phrs.2013.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 01/09/2013] [Accepted: 01/15/2013] [Indexed: 12/19/2022]
Abstract
Nociceptin/orphanin FQ (N/OFQ) and nociceptin orphanin peptide (NOP) receptors represent an endogenous system modulating gastrointestinal functions and inflammation. We investigated the peripheral effect of N/OFQ and of UFP-101, the NOP antagonist, in a model of colitis induced by TNBS (2,4,6 trinitrobenzenesulphonic acid; 60mg/kg). Male rats received two intraperitoneal injections per day of N/OFQ, UFP-101 or saline for 3 days after colitis induction. Four days after TNBS, animals were sacrificed and colonic histological damage, myeloperoxidase (MPO) activity and cytokine (IL-1β and IL-10) levels were evaluated. N/OFQ plasmatic levels were assessed by radioimmunoassay. TNBS increased all the inflammatory variables considered. In colitic rats, N/OFQ (0.02 and 0.2nmol/kg) improved microscopic damage, MPO activity and decreased IL-1β levels in comparison with TNBS group, whereas at the highest dose (20nmol/kg) the peptide worsened colitis. UFP-101 at the dose of 1nmol/kg, without pharmacological activity, antagonised the protective effect of N/OFQ (0.2nmol/kg) on colitis, but at a dose level of 3 and 10nmol/kg worsened inflammation, revealing the endogenous N/OFQergic system protective role. N/OFQ plasmatic levels were not modified in TNBS-treated rats compared with controls, whereas they were reduced in rats treated with the doses of UFP-101 aggravating colitis. In conclusion, peripheral low doses of N/OFQ have a beneficial effect on colonic inflammation in rats. In contrast, N/OFQ at a dose 100-1000-fold higher than those that protect worsens colitis, probably through different mechanisms. The peripheral N/OFQergic system can represent a new field of investigation in some intestinal inflammatory conditions.
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Affiliation(s)
- Carla Petrella
- Department of Physiology and Pharmacology V. Erspamer, Sapienza University of Rome, Rome, Italy.
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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
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Nishimura H, Li J, Isozaki K, Okada K, Matsushima A, Nose T, Costa T, Shimohigashi Y. Discriminatory synergistic effect of Trp-substitutions in superagonist [(Arg/Lys)(14), (Arg/Lys)(15)]nociceptin on ORL1 receptor binding and activation. Bioorg Med Chem 2009; 17:5683-7. [PMID: 19577933 DOI: 10.1016/j.bmc.2009.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 06/03/2009] [Accepted: 06/05/2009] [Indexed: 10/20/2022]
Abstract
ORL1 is an endogenous G protein-coupled receptor for neuropeptide nociceptin. [(R/K)(14), (R/K)(15)]nociceptin is a superagonist that strongly activates the ORL1 receptor. We have previously found that substituting with Trp can reproduce the potentiation induced by Arg or Lys at position 14. In the present study, in order to ensure the effect of Trp-substitution on the activities of [(R/K)(14), (R/K)(15)]nociceptin, we synthesized [W(14), (R/K)(15)]nociceptin and [(R/K)(14), W(15)]nociceptin. [W(14), (R/K)(15)]nociceptin was found to exhibit threefold higher binding activity and 10-fold greater potency in a functional [(35)S]GTPgammaS functional assay as compared to wild-type nociceptin. However, when only Trp was placed in position 15, the resulting analogues, [(R/K)(14), W(15)]nociceptin, showed only a moderate enhancement of binding and biological activity (2-3 fold in both). These results indicate that the placement of Trp at position 14, unlike at position 15, enhances in a synergistic fashion the interaction of nociceptin with the ORL1 receptor. The results indicate that specific interactions feasible for Arg/Lys and Trp in common must be there for aromatic residues in ORL1, thus forming a cation/pi interaction or pi/pi hydrophobic interaction. The necessity for a favorable electrostatic interaction appears strict in position 15.
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Affiliation(s)
- Hirokazu Nishimura
- Laboratory of Structure-Function Biochemistry, Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
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Okada K, Isozaki K, Li J, Matsushima A, Nose T, Costa T, Shimohigashi Y. Synergistic effect of basic residues at positions 14-15 of nociceptin on binding affinity and receptor activation. Bioorg Med Chem 2008; 16:9261-7. [PMID: 18818087 DOI: 10.1016/j.bmc.2008.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 08/30/2008] [Accepted: 09/05/2008] [Indexed: 11/20/2022]
Abstract
Nociceptin is an endogenous ligand that activates a G protein-coupled receptor ORL1 and contains two indispensable Arg-Lys (RK) dipeptide units at positions 8-9 and 12-13. By replacing an additional RK unit at positions 6-7, 10-11, 14-15, or 16-17, of the peptide we have identified the analog, [RK(14-15)]nociceptin as a superagonist. In fact, this peptide exhibits 3-fold higher binding affinity and 17-fold greater potency in a functional GTPgammaS-binding assay compared to wild-type nociceptin. Here, we have further investigated the role of basic residues in position 14-15. The replacement of three other possible basic dipeptides, KR, RR, and KK, into nociceptin at positions 14-15 resulted in similar enhancements of binding affinity (3-5-fold) and biological potency (10-12-fold in the GTPgammaS assay). However, when only a single basic residue (Arg or Lys) was replaced in either position 14 or 15, all the resulting analogs showed moderate enhancements of binding and biological activity (2-4-fold in both). These results indicate that the addition of basic charges in positions 14 and 15 enhance in a synergistic fashion the interaction of nociceptin with the receptor and only the simultaneous presence of two adjacent basic residues yields an optimal effect. This suggests that specific electrostatic interactions between both amino acids present in 14-15 and corresponding residues in the receptor are responsible for the enhancement of nociceptin activity.
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Affiliation(s)
- Kazushi Okada
- Laboratory of Structure-Function Biochemistry, Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
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Broccardo M, Agostini S, Petrella C, Guerrini R, Improta G. Central and peripheral role of the nociceptin/orphaninFQ system on normal and disturbed colonic motor function and faecal pellet output in the rat. Neurogastroenterol Motil 2008; 20:939-48. [PMID: 18410266 DOI: 10.1111/j.1365-2982.2008.01120.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this study, seeking further information on the role of the nociceptin/orphanin FQ (N/OFQ)-ergic system in normal and disturbed colonic motor function in rats, we compared the colonic effects of UFP-112, a novel highly potent agonist, with those of N/OFQ. When injected intracerebroventricularly (i.c.v.) and intraperitoneally (i.p.), UFP-112 and N/OFQ increased bead expulsion time in a statistically significant and dose-related manner and reduced the percentage of rats with castor oil-induced diarrhoea. UFP-112 showed greater efficacy, higher potency and longer-lasting inhibitory effects than N/OFQ, and pretreatment with UFP-101, a selective antagonist, blocked the N/OFQ analogue-induced responses in both tests. When injected i.c.v., UFP-112 and N/OFQ inhibited corticotrophin releasing factor- and restrain stress-stimulated faecal pellet excretion significantly and in a dose-related manner. Conversely, when injected peripherally both peptides significantly inhibited colonic propulsive motility but did so in a non-dose-related manner. In conclusion, these findings indicate that, in the rat, the central and peripheral N/OFQ systems have an inhibitory role in modulating distal colonic propulsive motility under physiological and pathological conditions. UFP-112 therefore promises to be a useful pharmacological tool for investigating the role of the N/OFQ system in motor functions in the distal colonic tract under physiological and pathological conditions.
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Affiliation(s)
- M Broccardo
- Department of Human Physiology and Pharmacology "V. Erspamer", University of Rome "Sapienza", Rome, Italy.
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Broccardo M, Guerrini R, Morini G, Polidori C, Agostini S, Petrella C, Improta G. The gastric effects of UFP-112, a new nociceptin/orphanin receptor agonist, in physiological and pathological conditions. Peptides 2007; 28:1974-81. [PMID: 17765363 DOI: 10.1016/j.peptides.2007.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 07/23/2007] [Accepted: 07/23/2007] [Indexed: 11/26/2022]
Abstract
Nociceptin/orphanin FQ (N/OFQ), the endogenous NOP receptor ligand, centrally modulates gastric motor and secretory functions and prevents ethanol-induced gastric lesions in rats. A recently synthesized N/OFQ analog, [(pF)Phe(4)Aib(7)Arg(14)Lys(15)]N/OFQ-NH(2) (UFP-112), acts as a highly potent and selective peptide agonist for NOP receptors and produces longer-lasting in vitro and in vivo effects in mice than the natural ligand N/OFQ. In this study, we evaluated the effects of centrally (intracerebroventricularly/icv) and peripherally (intraperitoneally/ip) injected UFP-112 on gastric emptying and gastric acid secretion, and on the development of gastric mucosal lesions induced by 50% ethanol in the rat. When injected icv, it dose-dependently delayed gastric emptying of a phenol red meal (by up to 70%), decreased gastric secretion in water-loaded rats after 90 pylorus ligature, and reduced ethanol-induced gastric lesions (by up to 87%). In all three assays, UFP-112 was more effective than N/OFQ. The highly selective NOP receptor antagonist, UFP-101, decreased the efficacy of UFP-112, thus confirming that central NOP receptors mediate inhibitory control on these functional and pathological conditions in rats. Ip injected N/OFQ and UFP-112 induced non-dose-related gastric hypersecretory and antiulcer effects, which UFP-101 partially abolished. Ip N/OFQ appeared equiactive but about 30-100 times less potent than ip UFP-112 in stimulating gastric acid secretion and preventing lesion formation. When ip injected, both UFP-112 and N/OFQ left gastric emptying in rats unchanged, suggesting that peripheral NOP receptors have a role in mediating gastric hypersecretory and antiulcer effects but are not involved in regulating gastric motility. In addition, the inhibitory effects induced by this novel NOP receptor agonist lasted longer than those induced by N/OFQ. In conclusion, UFP-112 is a promising new pharmacological tool for studying the functional roles of the central and peripheral N/OFQ receptor system.
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Affiliation(s)
- M Broccardo
- Department of Human Physiology and Pharmacology, University of Rome La Sapienza, Italy
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Scoto GM, Aricò G, Ronsisvalle S, Parenti C. Blockade of the nociceptin/orphanin FQ/NOP receptor system in the rat ventrolateral periaqueductal gray potentiates DAMGO analgesia. Peptides 2007; 28:1441-6. [PMID: 17628212 DOI: 10.1016/j.peptides.2007.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 05/30/2007] [Accepted: 05/30/2007] [Indexed: 11/21/2022]
Abstract
Nociceptin/orphanin FQ (N/OFQ) and its receptor (NOP) are involved in various biological functions including pain. High density of NOP receptor has been found in the ventrolateral periaqueductal gray (vlPAG), the main output pathway involved in descending pain-control system. The aim of our work was to evaluate the involvement of the N/OFQ/NOP system in the modulation of MOP analgesia in the rat vlPAG using UFP-101, a selective NOP antagonist. N/OFQ significantly blocked DAMGO (a selective MOP agonist) analgesia, while UFP-101 enhanced the effect of the opioid given at a subanalgesic dose. These results confirm our hypothesis of an antiopioid role for N/OFQ in the vlPAG.
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Affiliation(s)
- Giovanna M Scoto
- Department of Pharmaceutical Sciences-Pharmacology Section, University of Catania, v.le A. Doria 6, 95125 Catania, Italy.
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Nazzaro C, Rizzi A, Salvadori S, Guerrini R, Regoli D, Zeilhofer HU, Calo G. UFP-101 antagonizes the spinal antinociceptive effects of nociceptin/orphanin FQ: behavioral and electrophysiological studies in mice. Peptides 2007; 28:663-9. [PMID: 17161885 DOI: 10.1016/j.peptides.2006.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 11/06/2006] [Accepted: 11/07/2006] [Indexed: 10/23/2022]
Abstract
Nociceptin/orphanin FQ (N/OFQ) modulates various biological functions, including nociception, via selective stimulation of the N/OFQ peptide receptor (NOP). Here we used the NOP selective antagonist UFP-101 to characterize the receptor involved in the spinal antinociceptive effects of N/OFQ evaluated in the mouse tail withdrawal assay and to investigate the mechanism underlying this action by assessing excitatory postsynaptic currents (EPSC) in laminas I and II of the mouse spinal cord dorsal horn with patch-clamp techniques. Intrathecal (i.t.) injection of N/OFQ in the range of 0.1-10 nmol produced a dose dependent antinociceptive effect, which was prevented by UFP-101, but not by naloxone. In contrast the antinociceptive effect of the mu-opioid peptide receptor agonist endomorphin-1 was blocked by naloxone but not by UFP-101. Moreover, N/OFQ and endomorphin-1 induced a significant antinociceptive effect in wild type mice while in mice knockout for the NOP receptor gene only endomorphin-1 was found to be active. In mouse spinal cord slices 1 microM N/OFQ reduced EPSC to 60+/-4% of control values. This inhibitory effect was reversed in a concentration dependent manner by UFP-101 (pA2 value 6.44). The present results demonstrate that N/OFQ-induced spinal antinociception in vivo and inhibition of spinal excitatory transmission in vitro are mediated by receptors of the NOP type.
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Affiliation(s)
- Cristiano Nazzaro
- Department of Experimental and Clinical Medicine, Section of Pharmacology and Neuroscience Center, via Fossato di Mortara 19, 44100 Ferrara, Italy
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Li HY, Yan X, Xue QL, Zhou YN, Gao Y, Wang R, Liu YM, Ran JT. Effects of nociceptin/orphanin FQ on rats with cathartic colon. World J Gastroenterol 2007; 13:141-5. [PMID: 17206761 PMCID: PMC4065871 DOI: 10.3748/wjg.v13.i1.141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 05/15/2006] [Accepted: 07/10/2006] [Indexed: 02/06/2023] Open
Abstract
AIM To demonstrate the change and effect of nociceptin/orphanin FQ in the colon of rats with cathartic colon. METHODS The cathartic colon model was established by feeding rats rhubarb for 3 mo, the changes of colonic electromyography were investigated by both suspension muscle strips test and serosal recordings of colonic myoelectrical activity. Immunohistochemical staining (S-P methods) and image analysis were used to determine the changes of nociceptin/orphanin FQ in the proximal colon and distal colon of rats with cathartic colon. RESULTS Suspension muscle strips test in vitro showed OFQ (10(-9)-10(-6) mol/L) concentration dependently caused an immediate tonic contraction in the isolated colon. But the increase of tension in cathartic colon was less than control groups (P < 0.01). Intravenous administration of OFQ (1 microg/kg) caused phasic contractions in the proximal colon, while the amplitude of phasic contractions caused by OFQ in cathartic colon was much lower than that in the control groups (2.58 +/- 0.41 vs 4.16 +/- 0.53, t = -2.6, P = 0.012). OFQ was highly expressed in the myenteric plexus of the rat colon but not in the muscle cells. The immunoreactivity of OFQ in the proximal colon in cathartic colon rats decreased significantly compared with the control group (P = 0.001). CONCLUSION Colonic smooth muscle of cathartic colon showed low sensitivity to the stimulation of OFQ, suggesting that it might be caused by the abnormal distribution of OFQ or the abnormalities of receptors, leading to the disorganization of dynamic and incoordinated contractions.
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Affiliation(s)
- Hai-Yan Li
- Department of Geriatrics, 1st Affiliated Hospital of Lanzhou University, Lanzhou 730000, Gansu Province, China.
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Abstract
This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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Linari G, Agostini S, Broccardo M, Petrella C, Improta G. Regulation of pancreatic secretion in vitro by nociceptin/orphanin FQ and opioid receptors: A comparative study. Pharmacol Res 2006; 54:356-60. [PMID: 16979347 DOI: 10.1016/j.phrs.2006.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 07/05/2006] [Accepted: 07/10/2006] [Indexed: 12/12/2022]
Abstract
The effects of nociceptin/orphanin FQ (N/OFQ) on gastrointestinal functions resemble those of classic analgesic opioid agonists. In this study, we compared changes in amylase release from guinea pig isolated pancreatic acini and lobules induced by the N/OFQ analogue [Arg(14),Lys(15)]N/OFQ and by the delta-receptor opioid agonist deltorphin. Carbachol strongly stimulated amylase release from isolated acini. Both peptides left baseline and carbachol-stimulated amylase secretion from pancreatic acini unchanged. Co-incubation of KCl-stimulated lobules with [Arg(14),Lys(15)]N/OFQ or deltorphin inhibited KCl-induced amylase release in a concentration-dependent manner. Although maximal inhibition of amylase release by [Arg(14),Lys(15)]N/OFQ and deltorphin had similar amplitude, [Arg(14),Lys(15)]N/OFQ was 100-fold more potent than deltorphin on a molar basis. The selective NOP-receptor antagonist [Nphe(1),Arg(14),Lys(15)]N/OFQ-NH(2) (UFP-101) antagonized [Arg(14),Lys(15)]N/OFQ-induced inhibition but left deltorphin-induced inhibition unchanged. The selective delta opiate receptor antagonist naltrindole had no effect on [Arg(14),Lys(15)]N/OFQ inhibition but partly prevented the inhibition by deltorphin. [Arg(14),Lys(15)]N/OFQ and deltorphin combined had no influence on each other. These findings show that [Arg(14),Lys(15)]N/OFQ inhibits pancreatic enzyme secretion by suppressing cholinergic transmission in intralobular nerve fibers, as previously reported for opioid agents. They suggest that [Arg(14),Lys(15)]N/OFQ inhibition of amylase release is mediated through the NOP receptor and not through the delta opioid receptor. The N/OFQ-NOP receptor system, like the delta opioid system, plays an inhibitory role in regulating exocrine pancreatic secretion.
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Affiliation(s)
- Giorgio Linari
- University La Sapienza, Fisiologia Umana e Farmacologia, Piazzale A. Moro 5, 00185 Roma, RM, Italy.
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Li HY, Li DX, Yan X, Peng SY, Cui L, Cao JM. Effects of orphanin FQ on colonic motility of rats. Shijie Huaren Xiaohua Zazhi 2006; 14:1377-1381. [DOI: 10.11569/wcjd.v14.i14.1377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the role of ORL1 (opioid receptor-like 1) receptor in the colon movement.
METHODS: The test for tension of colonic muscle strips in vitro and the colonic myoelectrical activity in vivo as well as the charcoal suspension pushing test were performed to evaluate the effect of orphanin FQ (OFQ) on the motility of colon.
RESULTS: NOFQ (1-1000 nmol/L) caused an immediate tonic contraction in the isolated colon in a concentration-dependent manner. In anesthetized rats, intravenous administration of OFQ (1 mg/kg) caused phasic contractions in the proximal colon (t = 2.41, P = 0.02), and this contraction was not inhibited by classical opioid receptor antagonist, naloxone. Subcutaneous administration of OFQ (3 nmol/kg) accelerated the colonic transit of charcoal suspension in vivo (48.0 ± 1.24 vs 43.5 ± 2.63, t = -4.5, P = 0.008).
CONCLUSION: OFQ is a brain-gut peptide and plays a role in the modulation of gastrointestinal functions.
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