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Yuan PQ, Wu SV, Stengel A, Sato K, Taché Y. Activation of CRF 1 receptors expressed in brainstem autonomic nuclei stimulates colonic enteric neurons and secreto-motor function in male rats. Neurogastroenterol Motil 2021; 33:e14189. [PMID: 34215021 DOI: 10.1111/nmo.14189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/13/2021] [Accepted: 05/04/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Hypothalamic corticotropin-releasing factor (CRF) receptor 1 (CRF1 ) plays a role in acute stress-related stimulation of colonic motor function. Less is known on CRF1 signaling in the brainstem. METHODS We investigate CRF1 expression in the brainstem and the colonic response to 4th ventricle (4V) injection of CRF and urocortin (Ucn) 2 (3 µg/rat) in chronically cannulated male rats. KEY RESULTS Transcripts of CRF1 wild-type 1a and splice variants 1c, 1e, 1f, 1o along with three novel variants 1a-2 (desK-110 in exon 5), 1p (-exon 7), and 1q (exon 5 extension) were identified in the pons and medulla. The area postrema, nucleus tractus solitarius, dorsal motor nucleus of the vagus, locus coeruleus, and Barrington's nucleus isolated by laser capture microdissection expressed 1a, 1a-2, and 1p but not 1q. Compared to 4V vehicle, 4V CRF induced fecal pellet output (FPO) and diarrhea that were blocked by the CRF antagonist, astressin-B. CRF2 agonist, Ucn2 had no effect on basal or CRF-induced FPO. CRF actions were correlated with the induction of c-Fos immunoreactivity in myenteric neurons of the proximal and distal colon (pC, dC) and submucosal neurons of dC. c-Fos immunoreactivity occurred in 39% and 37% of myenteric cholinergic and 7% and 58% of nitrergic neurons in the pC and dC, respectively. CONCLUSIONS & INFERENCES CRF1a and its splice variants are expressed in brainstem nuclei, and activation of CRF1 signaling at the level of the brainstem stimulates colonic secretory-motor function through activation of colonic enteric neurons.
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Affiliation(s)
- Pu-Qing Yuan
- David Geffen School of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California at Los Angeles (UCLA), Los Angeles, CA, USA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - S Vincent Wu
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Andreas Stengel
- David Geffen School of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California at Los Angeles (UCLA), Los Angeles, CA, USA
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital, Tübingen, Germany
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Charité-Universitätsmedizin, Berlin, Germany
| | - Ken Sato
- David Geffen School of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California at Los Angeles (UCLA), Los Angeles, CA, USA
- Sato Clinic 13-14 Choei Moriyamaku, Nagoya City, Japan
| | - Yvette Taché
- David Geffen School of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California at Los Angeles (UCLA), Los Angeles, CA, USA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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Ueda HH, Naitou K, Nakamori H, Horii K, Shiina T, Masatani T, Shiraishi M, Shimizu Y. α-MSH-induced activation of spinal MC1R but not MC4R enhances colorectal motility in anaesthetised rats. Sci Rep 2021; 11:487. [PMID: 33436759 PMCID: PMC7803980 DOI: 10.1038/s41598-020-80020-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022] Open
Abstract
The central nervous system is involved in regulation of defaecation. It is generally considered that supraspinal regions control the spinal defaecation centre. However, signal transmission from supraspinal regions to the spinal defaecation centre is still unclear. In this study, we investigated the regulatory role of an anorexigenic neuropeptide, α-MSH, in the spinal defaecation centre in rats. Intrathecal administration of α-MSH to the L6-S1 spinal cord enhanced colorectal motility. The prokinetic effect of α-MSH was abolished by severing the pelvic nerves. In contrast, severing the colonic nerves or thoracic cord transection at the T4 level had no impact on the effect of α-MSH. RT-PCR analysis revealed MC1R mRNA and MC4R mRNA expression in the L6-S1 spinal cord. Intrathecally administered MC1R agonists, BMS470539 and SHU9119, mimicked the α-MSH effect, but a MC4R agonist, THIQ, had no effect. These results demonstrate that α-MSH binds to MC1R in the spinal defaecation centre and activates pelvic nerves, leading to enhancement of colorectal motility. This is, to our knowledge, the first report showing the functional role of α-MSH in the spinal cord. In conclusion, our findings suggest that α-MSH is a candidate for a neurotransmitter from supraspinal regions to the spinal defaecation centre.
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Affiliation(s)
- Hiromi H Ueda
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Hiroyuki Nakamori
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| | - Kazuhiro Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Takahiko Shiina
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Tatsunori Masatani
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Mitsuya Shiraishi
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Yasutake Shimizu
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan. .,Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University (G-CHAIN), Gifu, Japan.
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He Y, Yang C, Wang P, Yang L, Wu H, Liu H, Qi M, Guo Z, Li J, Shi H, Wu X, Hu Z. Child compound Endothelium corneum attenuates gastrointestinal dysmotility through regulating the homeostasis of brain-gut-microbiota axis in functional dyspepsia rats. JOURNAL OF ETHNOPHARMACOLOGY 2019; 240:111953. [PMID: 31082513 DOI: 10.1016/j.jep.2019.111953] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 04/24/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nowadays, there is no specific effective western medicine for functional dyspepsia (FD), especially in children. Clinically, child compound Endothelium corneum (CCEC) has shown to be effective for the therapy of FD, however, the underlying mechanism has not been elucidated yet. MATERIALS AND METHODS FD was induced in rats by irregular diet plus dilute hydrochloric acid feeding. Gastric emptying and small intestinal transit were examined by intragastric gavage with Evans blue. Histopathology was assessed by H&E staining. Gastrointestinal hormones and brain gut peptides were measured by ELISA assay. mRNA expression level was quantified by real-time PCR. Protein expression level was detected by western blotting assay. Gut microbiota was analyzed by 16S rRNA miseq sequencing. RESULTS CCEC significantly enhanced gastric emptying and small intestinal transit of FD rats, and prominently suppressed gastrointestinal microinflammation. At phylum level, CCEC prevented the decrease of Firmicutes and the increase of Bacteroidetes in gut of FD rats. In stomach of FD rats, MTL, CCK and VIP levels were significantly increased, which could be repressed by CCEC; however, the decreased GAS level could not be elevated by CCEC. In small intestine of FD rats, MTL and GAS levels were decreased, while VIP content was increased. These alterations could be effectively reversed by CCEC. NPY levels in serum, small intestine and hypothalamus of FD rats were significantly decreased, which could be rescued by CCEC. Moreover, the over-activated POMC/Stat3/Akt pathway in hypothalamus of FD rats could be suppressed by CCEC. CONCLUSION CCEC enhanced gastrointestinal motility probably through rebalancing the homeostasis of brain-gut-microbiota axis in FD rats. The novel findings may provide insightful theoretical basis for its clinical employment.
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Affiliation(s)
- Yixin He
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China; School of Pharmacy, Zhengzhou University, Zhengzhou, 450001, China.
| | - Chun Yang
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Ping Wang
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Liu Yang
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Hui Wu
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Hongmin Liu
- School of Pharmacy, Zhengzhou University, Zhengzhou, 450001, China.
| | - Muge Qi
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Zhonghua Guo
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Jianghua Li
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Hailian Shi
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Xiaojun Wu
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Zhibi Hu
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
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Tache Y, Larauche M, Yuan PQ, Million M. Brain and Gut CRF Signaling: Biological Actions and Role in the Gastrointestinal Tract. Curr Mol Pharmacol 2018; 11:51-71. [PMID: 28240194 DOI: 10.2174/1874467210666170224095741] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/16/2016] [Accepted: 08/03/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Corticotropin-releasing factor (CRF) pathways coordinate behavioral, endocrine, autonomic and visceral responses to stress. Convergent anatomical, molecular, pharmacological and functional experimental evidence supports a key role of brain CRF receptor (CRF-R) signaling in stress-related alterations of gastrointestinal functions. These include the inhibition of gastric acid secretion and gastric-small intestinal transit, stimulation of colonic enteric nervous system and secretorymotor function, increase intestinal permeability, and visceral hypersensitivity. Brain sites of CRF actions to alter gut motility encompass the paraventricular nucleus of the hypothalamus, locus coeruleus complex and the dorsal motor nucleus while those modulating visceral pain are localized in the hippocampus and central amygdala. Brain CRF actions are mediated through the autonomic nervous system (decreased gastric vagal and increased sacral parasympathetic and sympathetic activities). The activation of brain CRF-R2 subtype inhibits gastric motor function while CRF-R1 stimulates colonic secretomotor function and induces visceral hypersensitivity. CRF signaling is also located within the gut where CRF-R1 activates colonic myenteric neurons, mucosal cells secreting serotonin, mucus, prostaglandin E2, induces mast cell degranulation, enhances mucosal permeability and propulsive motor functions and induces visceral hyperalgesia in animals and humans. CRF-R1 antagonists prevent CRF- and stressrelated gut alterations in rodents while not influencing basal state. DISCUSSION These preclinical studies contrast with the limited clinical positive outcome of CRF-R1 antagonists to alleviate stress-sensitive functional bowel diseases such as irritable bowel syndrome. CONCLUSION The translational potential of CRF-R1 antagonists in gut diseases will require additional studies directed to novel anti-CRF therapies and the neurobiology of brain-gut interactions under chronic stress.
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Affiliation(s)
- Yvette Tache
- CURE/Digestive Diseases Research Center, G Oppenheimer Center for Neurobiology of Stress and Resilience, Vatche and Tamar Manoukian Digestive Diseases Division, David Geffen School of Medicine at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073. United States
| | - Muriel Larauche
- CURE/Digestive Diseases Research Center, G Oppenheimer Center for Neurobiology of Stress and Resilience, Vatche and Tamar Manoukian Digestive Diseases Division, David Geffen School of Medicine at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073. United States
| | - Pu-Qing Yuan
- CURE/Digestive Diseases Research Center, G Oppenheimer Center for Neurobiology of Stress and Resilience, Vatche and Tamar Manoukian Digestive Diseases Division, David Geffen School of Medicine at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073. United States
| | - Mulugeta Million
- CURE/Digestive Diseases Research Center, G Oppenheimer Center for Neurobiology of Stress and Resilience, Vatche and Tamar Manoukian Digestive Diseases Division, David Geffen School of Medicine at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073. United States
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Yang Y, Babygirija R, Zheng J, Shi B, Sun W, Zheng X, Zhang F, Cao Y. Central Neuropeptide Y Plays an Important Role in Mediating the Adaptation Mechanism Against Chronic Stress in Male Rats. Endocrinology 2018; 159:1525-1536. [PMID: 29425286 DOI: 10.1210/en.2018-00045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 01/17/2018] [Indexed: 12/31/2022]
Abstract
Exposure to continuous life stress often causes gastrointestinal (GI) symptoms. Studies have shown that neuropeptide Y (NPY) counteracts the biological actions of corticotrophin-releasing factor (CRF) and is involved in the termination of the stress response. However, in chronic repeated restraint stress (CRS) conditions, the actions of NPY on GI motility remain controversial. To evaluate the role of NPY in mediation of the adaptation mechanism and GI motility in CRS conditions, a CRS rat model was set up. Central CRF and NPY expression levels were analyzed, serum corticosterone and NPY concentrations were measured, and GI motor function was evaluated. The NPY Y1 receptor antagonist BIBP-3226 was centrally administered before stress loading, and on days 1 through 5 of repeated stress, the central CRF and the serum corticosterone concentrations were measured. In addition, gastric and colonic motor functions were evaluated. The elevated central CRF expression and corticosterone concentration caused by acute stress began to fall after 3 days of stress loading, whereas central NPY expression and serum NPY began to increase. GI dysmotility also returned to a normal level. Pretreatment with BIBP-3226 abolished the adaptation mechanism and significantly increased CRF expression and the corticosterone concentration, which resulted in delayed gastric emptying and accelerated fecal pellet output. Inhibited gastric motility and enhanced distal colonic motility were also recorded. CRS-produced adaptation, overexpressed central CRF, and GI dysmotility observed in acute restraint stress were restored to normal levels. Central NPY via the Y1 receptor plays an important role in mediating the adaptation mechanism against chronic stress.
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Affiliation(s)
- Yu Yang
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Reji Babygirija
- Department of Surgery, Medical College of Wisconsin and Zablocki VA Medical Center, Milwaukee, Wisconsin
| | - Jun Zheng
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Bei Shi
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Weinan Sun
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Xiaojiao Zheng
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Fan Zhang
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Yu Cao
- Department of Physiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
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Taché Y, Million M. Role of Corticotropin-releasing Factor Signaling in Stress-related Alterations of Colonic Motility and Hyperalgesia. J Neurogastroenterol Motil 2015; 21:8-24. [PMID: 25611064 PMCID: PMC4288101 DOI: 10.5056/jnm14162] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 12/28/2014] [Indexed: 12/13/2022] Open
Abstract
The corticotropin-releasing factor (CRF) signaling systems encompass CRF and the structurally related peptide urocortin (Ucn) 1, 2, and 3 along with 2 G-protein coupled receptors, CRF1 and CRF2. CRF binds with high and moderate affinity to CRF1 and CRF2 receptors, respectively while Ucn1 is a high-affinity agonist at both receptors, and Ucn2 and Ucn3 are selective CRF2 agonists. The CRF systems are expressed in both the brain and the colon at the gene and protein levels. Experimental studies established that the activation of CRF1 pathway in the brain or the colon recaptures cardinal features of diarrhea predominant irritable bowel syndrome (IBS) (stimulation of colonic motility, activation of mast cells and serotonin, defecation/watery diarrhea, and visceral hyperalgesia). Conversely, selective CRF1 antagonists or CRF1/CRF2 antagonists, abolished or reduced exogenous CRF and stress-induced stimulation of colonic motility, defecation, diarrhea and colonic mast cell activation and visceral hyperalgesia to colorectal distention. By contrast, the CRF2 signaling in the colon dampened the CRF1 mediated stimulation of colonic motor function and visceral hyperalgesia. These data provide a conceptual framework that sustained activation of the CRF1 system at central and/or peripheral sites may be one of the underlying basis of IBS-diarrhea symptoms. While targeting these mechanisms by CRF1 antagonists provided a relevant novel therapeutic venue, so far these promising preclinical data have not translated into therapeutic use of CRF1 antagonists. Whether the existing or newly developed CRF1 antagonists will progress to therapeutic benefits for stress-sensitive diseases including IBS for a subset of patients is still a work in progress.
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Affiliation(s)
- Yvette Taché
- CURE/Digestive Diseases Research Center, and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Mulugeta Million
- CURE/Digestive Diseases Research Center, and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
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Forbes S, Herzog H, Cox HM. A role for neuropeptide Y in the gender-specific gastrointestinal, corticosterone and feeding responses to stress. Br J Pharmacol 2012; 166:2307-16. [PMID: 22404240 DOI: 10.1111/j.1476-5381.2012.01939.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Exposure to an acute stress inhibits gastric emptying and stimulates colonic transit via central neuropeptide Y (NPY) pathways; however, peripheral involvement is uncertain. The anxiogenic phenotype of NPY(-/-) mice is gender-dependent, raising the possibility that stress-induced gastrointestinal (GI) responses are female-dominant through NPY. The aim of this study was to determine GI transit rates, corticosterone levels and food intake after acute restraint (AR) or novel environment (NE) stress in male and female NPY(-/-) and WT mice. EXPERIMENTAL APPROACH Upper gastrointestinal transit (UGIT) (established 30 min after oral gavage) and corticosterone levels were determined under basal or restrained conditions (30 min) and after treatment i.p. with Y(1) antagonist BIBO3304 or Y(2) antagonist BIIE0246. Faecal pellet output (FPO) was established after AR and treatment i.p. with NPY in the NE, as were colonic bead expulsion rates. KEY RESULTS UGIT and FPO were similar in unrestrained male and female mice. NPY(-/-) females displayed significantly slower UGIT than NPY(-/-) males after AR, but both genders displayed significantly higher FPO and reduced food intake relative to WT counterparts. Peripheral NPY treatment increased bead expulsion time in WT mice. AR male NPY(-/-) mice had higher levels of corticosterone than male WT mice; whilst in AR WT mice, after peripheral Y(1) and Y(2) receptor antagonism in males, and Y(2) antagonism in females, corticosterone was significantly elevated. CONCLUSIONS AND IMPLICATIONS NPY possesses a role in the gender-dependent susceptibility to stress-induced GI responses. Furthermore, NPY inhibits GI motility through Y(2) receptors and corticosterone release via peripheral Y(1) and Y(2) receptors.
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Affiliation(s)
- S Forbes
- King's College London, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK.
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Kermani M, Eliassi A. Gastric acid secretion induced by paraventricular nucleus microinjection of orexin A is mediated through activation of neuropeptide Yergic system. Neuroscience 2012; 226:81-8. [PMID: 22986171 DOI: 10.1016/j.neuroscience.2012.08.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 08/05/2012] [Accepted: 08/22/2012] [Indexed: 12/25/2022]
Abstract
UNLABELLED Very recently, we have reported that the modulatory effect of PVN on gastric acid secretion may be mediated through the orexin fibers and/or orexin-responsive neurons. In this study, we address the hypothesis which demonstrates the existence of a putative orexin A - neuropeptide Y Y1/Y5 receptors interaction to increase gastric acid secretion in pyloric-ligated conscious rats. Male Wistar rats were implanted with guide canula directed to the PVN and lateral ventricle. Intracerebroventricular (ICV) microinjections of GR-231118 (Y1 receptor antagonist) and CGP-71683 (Y5 receptor antagonist) on gastric acid secretion were considered. The effect of pretreatment with Y1 receptor antagonist, GR-231118, and Y5 receptor antagonist, CGP-71683, on PVN orexin A-induced acid secretion was assessed. Gastric acid secretion was measured using the pylorus-ligation method, and the amount of gastric acid was determined by titration with 0.01N NaOH to a pH of 7.0. KEY RESULTS ICV microinjections of GR-231118 and CGP-71683 decreased acid secretion by 25±0.05% and 67±0.02%, respectively. ICV microinjections of GR-231118 and CGP-71683 inhibited effects of PVN-injected orexin-A on acid secretion. We suggest that Y1 and Y5 receptors stimulate gastric acid secretion and the stimulatory effect of PVN orexin receptors on gastric acid secretion may be mediated via interactions, at least in part, through activation of Y1 and Y5 receptors. These neural pathways may play key roles in the orexinergic action of orexins in the cephalic phase of gastric acid secretion.
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Affiliation(s)
- M Kermani
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Shi YC, Hämmerle CM, Lee ICJ, Turner N, Nguyen AD, Riepler SJ, Lin S, Sainsbury A, Herzog H, Zhang L. Adult-onset PYY overexpression in mice reduces food intake and increases lipogenic capacity. Neuropeptides 2012; 46:173-82. [PMID: 22575886 DOI: 10.1016/j.npep.2012.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 12/22/2022]
Abstract
Peptide YY (PYY) is best known for its important role in appetite regulation, but recent pharmacological studies have suggested that PYY is also involved in regulating energy balance and glucose homeostasis. However, the mechanism behind the regulation of these parameters by PYY is less clear. Here, by utilising an inducible transgenic mouse model where PYY overexpression is induced in adult animals (PYYtg) and release of mature PYY peptides is controlled by endogenous machineries, we show that elevating PYY levels leads to reduced food intake after a 24-h fast. Furthermore, PYYtg mice, although not significantly different from WT with respect to body weight, adiposity, lean mass, physical activity or energy expenditure, exhibited a significantly increased respiratory exchange ratio (RER), indicating decreased lipid oxidation and/or increased lipogenesis. Importantly, PYYtg mice showed a 25% reduction in liver protein levels of phosphorylated acetyl-CoA carboxylase (pACC) in the absence of changes in total ACC levels compared to those of WT mice. Moreover, liver protein levels of AMP-activated kinase (AMPK) in PYYtg mice were 25% lower than those of WT mice, consistent with a reduced pACC in these mice. These data suggest that elevation of PYY levels as seen after a meal can increase lipogenic capacity, which is likely a key contributor to the increased RER seen in PYYtg mice. In addition, PYYtg mice exhibited comparable insulin tolerance and oral glucose tolerance to those of WT, but showed a trend towards decreased insulin levels in response to an oral glucose challenge, indicating that PYY could improve insulin action. Taken together, these findings demonstrate that under physiological conditions, PYY reduces food intake while enhancing lipogenic capacity and insulin action, likely contributing to fuel assimilation in the postprandial state.
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Affiliation(s)
- Yan-Chuan Shi
- Neuroscience Research Program, Garvan Institute of Medical Research, 384 Victoria St., Darlinghurst, Sydney, NSW 2010, Australia
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Tough IR, Forbes S, Tolhurst R, Ellis M, Herzog H, Bornstein JC, Cox HM. Endogenous peptide YY and neuropeptide Y inhibit colonic ion transport, contractility and transit differentially via Y₁ and Y₂ receptors. Br J Pharmacol 2012; 164:471-84. [PMID: 21457230 DOI: 10.1111/j.1476-5381.2011.01401.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Peptide YY (PYY) and neuropeptide Y (NPY) activate Y receptors, targets under consideration as treatments for diarrhoea and other intestinal disorders. We investigated the gastrointestinal consequences of selective PYY or NPY ablation on mucosal ion transport, smooth muscle activity and transit using wild-type, single and double peptide knockout mice, comparing mucosal responses with those from human colon. EXPERIMENTAL APPROACH Mucosae were pretreated with a Y₁ (BIBO3304) or Y₂ (BIIE0246) receptor antagonist and changes in short-circuit current recorded. Colonic transit and colonic migrating motor complexes (CMMCs) were assessed in vitro and upper gastrointestinal and colonic transit measured in vivo. KEY RESULTS Y receptor antagonists revealed tonic Y₁ and Y₂ receptor-mediated antisecretory effects in human and wild-type mouse colon mucosae. In both, Y₁ tone was epithelial while Y₂ tone was neuronal. Y₁ tone was reduced 90% in PYY⁻/⁻ mucosa but unchanged in NPY⁻/⁻ tissue. Y₂ tone was partially reduced in NPY⁻/⁻ or PYY⁻/⁻ mucosae and abolished in tetrodotoxin-pretreated PYY⁻/⁻ tissue. Y₁ and Y₂ tone were absent in NPYPYY⁻/⁻ tissue. Colonic transit was inhibited by Y₁ blockade and increased by Y₂ antagonism indicating tonic Y₁ excitation and Y₂ inhibition respectively. Upper GI transit was increased in PYY⁻/⁻ mice only. Y₂ blockade reduced CMMC frequency in isolated mouse colon. CONCLUSIONS AND IMPLICATIONS Endogenous PYY and NPY induced significant mucosal antisecretory tone mediated by Y₁ and Y₂ receptors, via similar mechanisms in human and mouse colon mucosa. Both peptides contributed to tonic Y₂-receptor-mediated inhibition of colonic transit in vitro but only PYY attenuated upper GI transit.
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Affiliation(s)
- I R Tough
- King's College London, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK
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STENGEL A, GOEBEL-STENGEL M, WANG L, LARAUCHE M, RIVIER J, TACHÉ Y. Central somatostatin receptor 1 activation reverses acute stress-related alterations of gastric and colonic motor function in mice. Neurogastroenterol Motil 2011; 23:e223-36. [PMID: 21564422 PMCID: PMC3683311 DOI: 10.1111/j.1365-2982.2011.01706.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Corticotropin-releasing factor (CRF) signaling induced by stress is well established to delay gastric emptying (GE) and stimulate colonic functions. The somatostatin receptor (sst(1-5) ) agonist, ODT8-SST acts in the brain to inhibit stress-induced adrenocorticotropic hormone and epinephrine secretion. We investigated whether ODT8-SST acts in the brain to influence stress-related alterations of gastric and colonic motor function and sst receptor subtype(s) involved. METHODS Peptides were injected intracerebroventricularly (i.c.v.) under short isoflurane anesthesia and GE, fecal pellet output (FPO) and distal colonic motility monitored in conscious mice. KEY RESULTS The stress of acute anesthesia/vehicle i.c.v. injection reduced GE by 67% and increased defecation by 99% compared to non-injected controls. Both responses were abolished by ODT8-SST (1μg= 0.75nmol) or sst(1) agonist (0.65-1.95nmol). The sst(1) agonist (1.95nmol) also prevented the abdominal surgery-induced delayed GE. Octreotide (sst(2) >sst(5) > sst(3) ) and the sst(2) or sst(4) agonists (1μg=0.78 or 0.70nmol, respectively) injected i.c.v. did not influence FPO while i.c.v. somatostatin-28 mimicked ODT8-SST's effect. The ODT8-SST-induced increased food intake was inhibited by i.c.v. sst(2) antagonist while the reduced FPO was unchanged. ODT8-SST i.c.v. reduced distal colonic motility in semi-restrained mice compared with vehicle and blocked water avoidance- and i.c.v. CRF (0.5μg=0.09nmol)-induced stimulated FPO while a similar colonic secretomotor response to i.p. 5-hydroxytryptophane (10mgkg(-1) =36.4μmol kg(-1) ) was unaltered. Conclusions & Inferences ODT8-SST counteracts stress/i.c.v. CRF-related stimulation of colonic motor function and delayed GE which can be reproduced mainly by activation of sst(1) receptors. These data opens new insight to brain somatostatinergic signaling pathways interfering with brain circuitries involved in gut motor responses to acute stress.
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Affiliation(s)
- A. STENGEL
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - M. GOEBEL-STENGEL
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - L. WANG
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - M. LARAUCHE
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - J. RIVIER
- Peptide Biology Laboratories, Salk Institute, La Jolla, CA, USA
| | - Y. TACHÉ
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
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12
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Moriya R, Shirakura T, Hirose H, Kanno T, Suzuki J, Kanatani A. NPY Y2 receptor agonist PYY(3-36) inhibits diarrhea by reducing intestinal fluid secretion and slowing colonic transit in mice. Peptides 2010; 31:671-5. [PMID: 19925840 DOI: 10.1016/j.peptides.2009.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 12/20/2022]
Abstract
Peptide YY (PYY)(3-36), a neuropeptide Y (NPY) Y2 receptor agonist, is a powerful inhibitor of intestinal secretion. Based on this anti-secretory effect, NPY Y2 receptor agonists may be useful as novel anti-diarrheal agents, but anti-diarrheal efficacy has yet to be determined. We therefore examined the anti-diarrheal efficacy of PYY(3-36) and a selective Y2 receptor agonist, N-acetyl-[Leu28, Leu31]-NPY(24-36), in experimental mouse models of diarrhea. Intraperitoneal administration of PYY(3-36) (0.01-1mg/kg) and N-acetyl-[Leu28, Leu31]-NPY(24-36) (10mg/kg) significantly inhibited diarrhea (increase in wet fecal weight and diarrhea score) induced by dimethyl-prostaglandin E2, 5-hydroxytryptamine, and castor oil. Anti-diarrheal activities of PYY(3-36) and N-acetyl-[Leu28, Leu31]-NPY(24-36) were comparable to the effects of loperamide (1mg/kg), a widely used anti-diarrheal drug. To clarify the anti-diarrheal mechanisms of NPY Y2 receptor agonists, we investigated the effects of PYY(3-36) and N-acetyl-[Leu28, Leu31]-NPY(24-36) on intestinal fluid secretion and colonic transit. PYY(3-36) (1mg/kg) and N-acetyl-[Leu28, Leu31]-NPY(24-36) (10mg/kg) significantly reduced dimethyl-prostaglandin E2-induced intestinal fluid accumulation in conscious mice, suggesting that NPY Y2 receptor agonists inhibit diarrhea, at least in part, by reducing intestinal secretion. In addition, PYY(3-36) (0.01-1mg/kg) and N-acetyl-[Leu28, Leu31]-NPY(24-36) (10mg/kg) potently inhibited normal fecal output, suggesting that NPY Y2 receptor activation inhibits colonic motor function and NPY Y2 receptor agonists inhibit diarrhea partly by slowing colonic transit. These results indicate that NPY Y2 receptor agonists inhibit diarrhea in mice by not only reducing intestinal fluid secretion, but also slowing colonic transit, and illustrate the therapeutic potential of NPY Y2 receptor agonists as effective treatments for diarrhea.
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Affiliation(s)
- Ryuichi Moriya
- Tsukuba Research Institute, Banyu Pharmaceutical Co, Ltd, Okubo 3, Tsukuba 300-2611, Japan
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13
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Affiliation(s)
- Diana L Williams
- Department of Psychology, B328, PDB, 1107 West Call Street, Florida State University, Tallahassee, Florida 32306-4301, USA.
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14
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Salter-Venzon D, Watts AG. Site-specific attenuation of food intake but not the latency to eat after hypothalamic injections of neuropeptide Y in dehydrated-anorexic rats. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1813-21. [PMID: 19741057 DOI: 10.1152/ajpregu.00116.2009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Anorexia that accompanies cellular dehydration in rats (DE-anorexia) offers a relatively simple model for investigating the functional organization of neural mechanisms that can suppress feeding during dehydration. Previous studies strongly suggest that the inputs that drive ingestive behavior control neurons in the paraventricular nucleus of the hypothalamus (PVH) and lateral hypothalamic area (LHA) remain active during DE-anorexia. Here we examine whether these two regions retain their sensitivity to neuropeptide Y (NPY). NPY is an important component in two major feeding-related inputs from the arcuate nucleus and the hindbrain. We found that intake responses to NPY injections in the LHA and PVH were suppressed in DE-anorexia, but the PVH remained less sensitive to the effects of NPY than the LHA in DE-anorexic animals. Indeed the higher dose of NPY (238 pmol) completely overcame shorter periods of DE-anorexia when injected into the LHA but not the PVH. However, the latency to eat after NPY injections remained unchanged from control animals, regardless of NPY dose, injection location, or intensity of anorexia. Furthermore, the onset and size of the strong and rapidly induced compensatory feeding that follows the return of water to DE-anorexic animals was also unaffected by any NPY injections. These data support the hypothesis that DE-anorexia develops as a consequence of the premature termination of regularly initiated meals, which perhaps involves processes that alter the sensitivity of satiety mechanisms downstream to the PVH and LHA.
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Affiliation(s)
- Dawna Salter-Venzon
- The Neuroscience Graduate Program and Department of Biological Sciences, University of Southern California College, University of Southern California, Los Angeles, California 90089-2520, USA
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15
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Broccardo M, Scaccianoce S, Del Bianco P, Agostini S, Petrella C, Improta G. Nociceptin/orphanin FQ-induced delay in gastric emptying: role of central corticotropin-releasing factor and glucocorticoid receptors. Neurogastroenterol Motil 2005; 17:871-7. [PMID: 16336503 DOI: 10.1111/j.1365-2982.2005.00717.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
When injected intracerebroventricularly (i.c.v.) in rats, nociceptin/orphanin FQ (N/OFQ) delays gastric emptying and increases plasma corticosterone levels. Our aim in this study was to investigate changes in gastric emptying of a phenol red meal, and the plasma corticosterone response to N/OFQ in adrenalectomized (ADX) rats, in ADX rats injected with corticosterone at 1, 24 and 72 h before the gastric emptying assay, and in intact rats i.c.v. pretreated with a glucocorticoid antagonist (RU486) and with a corticotropin-releasing factor receptor antagonist (alpha-helical CRF9-41). In adrenal intact rats, i.c.v. injection of N/OFQ (2.5 nmol rat-1) significantly delayed gastric emptying (by 70%) and increased plasma corticosterone concentrations. Conversely, in ADX rats, N/OFQ left gastric emptying unchanged. In ADX rats, corticosterone injected at 1, 24 and 72 h before the gastric emptying assay almost restored the N/OFQ-induced delay in gastric emptying. Finally, pretreatment with RU486- and alpha-helical CRF9-41 abolished the N/OFQ-induced inhibition of gastric emptying. These findings suggest that central N/OFQ inhibits gastric emptying through an integrated orphaninergic system-CRF interaction in which corticosterone plays a permissive role.
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Affiliation(s)
- M Broccardo
- Department of Human Physiology and Pharmacology V. Erspamer, University of Rome La Sapienza, Rome, Italy.
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16
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Tebbe JJ, Mronga S, Tebbe CG, Ortmann E, Arnold R, Schäfer MKH. Ghrelin-induced stimulation of colonic propulsion is dependent on hypothalamic neuropeptide Y1- and corticotrophin-releasing factor 1 receptor activation. J Neuroendocrinol 2005; 17:570-6. [PMID: 16101895 DOI: 10.1111/j.1365-2826.2005.01340.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peptides participating in the hypothalamic control of feeding behaviour are also involved in the central autonomic control of gastrointestinal functions, such as secretion and motility. An anatomical interaction and functional relationship in the central nervous system between the feeding-related peptides neuropeptide Y and ghrelin is well documented. Furthermore, it has been shown that feeding-related peptides can influence digestive function via central corticotrophin-releasing factor (CRF) pathways. In the present study, we investigated the role of ghrelin in the central autonomic control of colonic motility. Furthermore, we addressed the hypothesis that ghrelin is involved in the hypothalamic control of colonic motor function, utilizing central neuropeptide Y receptors and hypothalamic CRF pathways. Ghrelin (0.03, 0.06 and 0.12 nmol) bilaterally microinjected into the paraventricular nucleus (PVN) induced a significant stimulation of colonic propulsion. In particular, the colonic transit time decreased from 312+/-7 min to 198+/-12 min. Microinjection of the neuropeptide Y1 receptor antagonist, BIBP-3226 (200 pmol), or the nonselective CRF receptor antagonist, astressin (30 pmol), into the PVN abolished the stimulatory effect of ghrelin injected into the PVN on colonic transit time, whereas pretreatment with the selective CRF2 receptor, antisauvagine-30 (28 pmol), failed to affect the effect of PVN-ghrelin injection on colonic propulsion. These results suggest that ghrelin can act as central modulator of gastrointestinal motor functions at the level of the PVN via neuropeptide Y1- and CRF1 receptor-dependent mechanisms.
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Affiliation(s)
- J J Tebbe
- Department of Internal Medicine, Division of Gastroenterology and Endocrinology, Philipps Universität Marburg, Marburg, Germany. ,de
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17
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Tebbe JJ, Pasat IR, Mönnikes H, Ritter M, Kobelt P, Schäfer MKH. Excitatory stimulation of neurons in the arcuate nucleus initiates central CRF-dependent stimulation of colonic propulsion in rats. Brain Res 2005; 1036:130-8. [PMID: 15725410 DOI: 10.1016/j.brainres.2004.12.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2004] [Revised: 09/29/2004] [Accepted: 12/11/2004] [Indexed: 12/16/2022]
Abstract
It is well established that autonomic control of digestive function is modulated by central autonomic neurotransmission. In this context it has been shown that digestive function can be modulated by exogenous neuropeptides microinjected into specific brain sides. Furthermore, there is considerable evidence suggesting that neurons projecting from the arcuate nucleus (ARC) to the PVN may be the source of endogenous neuropeptide release in the PVN. Neuronal projections from the ARC have been proposed to target corticotropin-releasing factor (CRF)-positive neurons in the PVN. Exogenous CRF in the PVN has been shown to modulate digestive function like gastric acid secretion and GI motility. Recently we have demonstrated that activation of ARC neurons inhibits gastric acid secretion via central CRF receptor dependent mechanisms. This poses the question whether neuronal activation of the ARC alters digestive function beside gastric acid secretion. In the present study we investigated whether CRF pathways in the ARC-PVN axis are involved in the modulation of colonic motility. First we examined the effect of an excitatory amino acid, kainate, microinjected into the ARC on colonic motility in anesthetized rats. Colonic motility was measured with a non-absorbable radioactive marker using the geometric center method. Kainate (120 pmol/rat) bilaterally microinjected into the ARC induced a significant stimulation of colonic propulsion. To assess the contribution of hypothalamic CRF to the effects of neuronal stimulation in the ARC on colonic motility we performed consecutive bilateral microinjections of an antagonist to CRF receptors into the PVN and the excitatory amino acid kainate into the ARC. Microinjection of the non-selective CRF receptor antagonist, astressin (100 ng), into the PVN abolished the stimulatory effect of neuronal activation in the ARC by kainate on colonic motor function. The data indicate that activation of neurons in the ARC stimulates colonic motility via CRF-receptor-mediated mechanism in the PVN and underlines the important role of the ARC-PVN circuit for the integrative CNS regulation of GI function.
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Affiliation(s)
- Johannes J Tebbe
- Department of Internal Medicine, Division Gastroenterology and Endocrinology, Philipps-Universität Marburg, Baldinger Strasse 1, 35033 Marburg, Germany.
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18
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Tebbe JJ, Tebbe CG, Mronga S, Ritter M, Schäfer MKH. Central neuropeptide Y receptors are involved in 3rd ventricular ghrelin induced alteration of colonic transit time in conscious fed rats. BMC Gastroenterol 2005; 5:5. [PMID: 15720710 PMCID: PMC554101 DOI: 10.1186/1471-230x-5-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 02/18/2005] [Indexed: 12/30/2022] Open
Abstract
Background Feeding related peptides have been shown to be additionally involved in the central autonomic control of gastrointestinal functions. Recent studies have shown that ghrelin, a stomach-derived orexigenic peptide, is involved in the autonomic regulation of GI function besides feeding behavior. Pharmacological evidence indicates that ghrelin effects on food intake are mediated by neuropeptide Y in the central nervous system. Methods In the present study we examine the role of ghrelin in the central autonomic control of GI motility using intracerobroventricular and IP microinjections in a freely moving conscious rat model. Further the hypothesis that a functional relationship between NPY and ghrelin within the CNS exists was addressed. Results ICV injections of ghrelin (0.03 nmol, 0.3 nmol and 3.0 nmol/5 μl and saline controls) decreased the colonic transit time up to 43%. IP injections of ghrelin (0.3 nmol – 3.0 nmol kg-1 BW and saline controls) decreased colonic transit time dose related. Central administration of the NPY1 receptor antagonist, BIBP-3226, prior to centrally or peripherally administration of ghrelin antagonized the ghrelin induced stimulation of colonic transit. On the contrary ICV-pretreatment with the NPY2 receptor antagonist, BIIE-0246, failed to modulate the ghrelin induced stimulation of colonic motility. Conclusion The results suggest that ghrelin acts in the central nervous system to modulate gastrointestinal motor function utilizing NPY1 receptor dependent mechanisms.
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Affiliation(s)
- Johannes J Tebbe
- Department of Internal Medicine, Division Gastroenterology – Endocrinology, Philipps Universität Marburg, 35033 Marburg, Germany
| | - Clemens G Tebbe
- Department of Internal Medicine, Division Gastroenterology – Endocrinology, Philipps Universität Marburg, 35033 Marburg, Germany
| | - Silke Mronga
- Department of Internal Medicine, Division Gastroenterology – Endocrinology, Philipps Universität Marburg, 35033 Marburg, Germany
| | - Michael Ritter
- Department of Internal Medicine, Division Cardiology, Philipps Universität Marburg, 35033 Marburg, Germany
| | - Martin KH Schäfer
- Department of Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps Universität Marburg, 35033 Marburg, Germany
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19
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Tebbe JJ, Ortmann E, Schumacher K, Mönnikes H, Kobelt P, Arnold R, Schäfer MKH. Cocaine- and amphetamine-regulated transcript stimulates colonic motility via central CRF receptor activation and peripheral cholinergic pathways in fed, conscious rats. Neurogastroenterol Motil 2004; 16:489-96. [PMID: 15306004 DOI: 10.1111/j.1365-2982.2004.00561.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Many neuropeptides participating in the hypothalamic control of feeding behaviour and satiety have been shown to be additionally involved in the autonomic control of gastrointestinal (GI) functions. Recently, the neuropeptide cocaine- and amphetamine-regulated transcript (CART) has been indicated to function as an anorectic substance in the brain. In the present study we examine the hypothesis that CART is involved in the modulation of GI motility. Colonic transit time was measured after peripheral and central injection of CART in fed and freely moving Sprague-Dawley rats. Intracerebroventricular injection of synthetic CART (55-102) (190 pmol and 1.9 nmol per 10 microL and saline controls) decreased the colonic transit time of conscious rats up to 46%. In contrast, i.p. injection of CART (55-102) (1.9 nmol and 19 nmol kg(-1) BW and saline controls) had no effect on colonic motility. Central administration of a CRF receptor antagonist (2.8 nmol) prior to central CART administration antagonized the CART-induced stimulation of colonic transit. Pretreatment with the peripherally acting cholinergic antagonist atropin methyl nitrate (0.1 mg kg(-1) i.p.) blocked the stimulatory CART effect on colonic motor function. The results suggest that CART acts in the central nervous system to modulate behavioural motor function via a central CRF receptor-dependent mechanism and peripheral cholinergic pathways.
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Affiliation(s)
- J J Tebbe
- Division of Gastroenterology and Endocrinology, Department of Internal Medicine, Philipps Universität Marburg, Baldinger Strasse 1, 35033 Marburg, Germany.
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20
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Tebbe JJ, Mronga S, Schäfer MKH, Rüter J, Kobelt P, Mönnikes H. Stimulation of neurons in rat ARC inhibits gastric acid secretion via hypothalamic CRF1/2- and NPY-Y1 receptors. Am J Physiol Gastrointest Liver Physiol 2003; 285:G1075-83. [PMID: 12855401 DOI: 10.1152/ajpgi.00125.2003] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Neuropeptide Y (NPY) neuronal projections from the arcuate nucleus (ARC) have been proposed to target corticotropin-releasing factor (CRF)-positive neurons in the paraventricular nucleus (PVN) as part of the ARC-PVN axis. The existence of a positive feedback loop involving CRF receptors in the PVN has been suggested. Exogenous NPY and CRF in the PVN have been shown to inhibit gastric acid secretion. Recently, we have demonstrated that activation of ARC neurons inhibits gastric acid secretion via vagal pathways. To what extent NPY- and CRF-mediated mechanisms in the PVN contribute to the CNS modulation of gastric acid secretion is still an open question. In the present study, we performed consecutive bilateral microinjections of antagonists to NPY receptor subtypes Y1 and Y2 and to CRF1/2 receptors in the PVN and of the excitatory amino acid kainate in the ARC to assess the role of NPY- and CRF-mediated mechanisms in the kainate-induced effects on gastric acid secretion. Gastric acid secretion was measured at the basal condition and during pentagastrin (16 microg/kg body wt) stimulation. Microinjection of vehicle in the PVN and kainate in the ARC decreased gastric acid secretion. Microinjection of the specific NPY-Y1 receptor antagonist BIBP-3226 (200 pmol) and the nonspecific CRF1/2 antagonist astressin (30 pmol) in the PVN abolished the inhibitory effect of neuronal activation in the ARC by kainate on gastric acid secretion. The CRF antagonist astressin was more effective. Pretreatment with the NPY-Y2 receptor antagonist BIIE-0246 (120 pmol) in the PVN had no significant effect. Our results indicate that activation of neurons in the ARC inhibits gastric acid secretion via CRF1/2 and NPY-Y1 receptor-mediated pathways in the PVN.
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Affiliation(s)
- Johannes J Tebbe
- Division of Gastroenterology and Endocrinology, Department of Internal Medicine, Philipps Universität Marburg, 35033 Marburg, Germany.
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21
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Affiliation(s)
- TADASHI ISHIGUCHI
- Department of Internal Medicine, Wakayama Medical University Kihoku Hospital, Katsuragicho, Ito‐gun, and
| | - HIDEKAZU ITOH
- Department of Internal Medicine, Wakayama Medical University Kihoku Hospital, Katsuragicho, Ito‐gun, and
| | - MASAO ICHINOSE
- The Second Department of Internal Medicine, Wakayama Medical University, Wakayama city, Wakayama, Japan
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22
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Tebbe JJ, Dietze T, Grote C, Mönnikes H. Excitatory stimulation of neurons in the arcuate nucleus inhibits gastric acid secretion via vagal pathways in anesthetized rats. Brain Res 2001; 913:10-7. [PMID: 11532242 DOI: 10.1016/s0006-8993(01)02746-9] [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: 12/16/2022]
Abstract
It is well established that autonomic control of gastrointestinal function is modulated by central autonomic neurotransmission. In this context it has been shown that gastrointestinal motility and secretion can be modulated by exogenous neuropeptides microinjected into the paraventricular nucleus of the hypothalamus (PVN). Furthermore, there is considerable evidence suggesting that neurons projecting from the arcuate nucleus (Arc) to the PVN may be the source of endogenous neuropeptide release in the PVN. This poses the question whether stimulation of neurons in the arcuate nucleus, e.g. by an excitatory amino acid, alters gastrointestinal function. In the present study, we investigated the effect of an excitatory amino acid, kainate, microinjected into the arcuate nucleus on gastric acid secretion in urethane-anesthetized rats. Kainate (140 pmol/rat) bilaterally microinjected into the Arc induced an significant inhibition of pentagastrin (PG) stimulated (16 mg/kg per h) gastric acid secretion throughout an observation period of 120 min after microinjection. Microinjection of kainate into hypothalamic areas outside the arcuate nucleus did not modify gastric secretion. Bilateral cervical vagotomy blocked the effect of kainate injected into the Arc on PG-stimulated gastric acid secretion. These data show that gastric secretory function can be modulated by stimulation of neuronal activity in the Arc via efferent vagal pathways. The results suggest that the arcuate nucleus is a forebrain area involved in the CNS regulation of gastrointestinal function.
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Affiliation(s)
- J J Tebbe
- Department of Anatomy and Cell Biology, Philipps-Universität zu Marburg, Marburg, Germany
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23
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Martínez V, Taché Y. Role of CRF receptor 1 in central CRF-induced stimulation of colonic propulsion in rats. Brain Res 2001; 893:29-35. [PMID: 11222989 DOI: 10.1016/s0006-8993(00)03277-7] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The CRF receptor subtype mediating the colonic and gastric motor responses to central CRF was investigated in conscious rats. CRF (0.6 microg/rat) injected intracerebroventicularly (i.c.v.) or 1 h water avoidance stress stimulated defecation (pellet/60 min: 4.1+/-1.0 and 8.7+/-0.7 respectively vs. 0.3+/-0.3 in i.c.v. vehicle/no stress). The CRF receptor 1 (CRF-R1) antagonist, NBI-27914 (50-100 microg/rat) injected i.c.v., abolished the colonic response to i.c.v. CRF and dose-dependently reduced that induced by water avoidance stress. NBI-27914 (100 microg/rat) injected peripherally did not influence the defecatory response to stress. The peptide CRF-R1/R2 antagonist, astressin (10 microg/rat, i.c.v.) inhibited the colonic motor response to i.c.v. CRF and stress similarly as NBI-27914 injected i.c.v. at 100 microg/rat. Intracisternal (i.c.) injection of astressin (10 microg/rat) also completely prevented CRF (0.6 g, i.c.)-induced delayed gastric emptying while i.c. NBI-27914 (50 or 100 microg) had no effect. These results indicate a differential role of central CRF receptor subtypes in the colonic stimulatory and gastric inhibitory motor responses to central CRF and that the CRF component of stress-related activation of colonic expulsion is primarily mediated by CRF-R1.
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Affiliation(s)
- V Martínez
- CURE: Digestive Diseases Research Center, Veterans Administration Greater Los Angeles Healthcare System, Department of Medicine, Digestive Disease Division and Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90073,USA
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Abstract
The Y(2) receptor is the predominant neuropeptide Y (NPY) receptor subtype in the brain. Y(2) receptor mRNA is discretely distributed in the brain, including specific subregions of the hippocampus and the hypothalamus, and is largely consistent with the distribution of Y(2) receptor protein demonstrated by radioligand-binding methods. Y(2) receptor-mediated effects have been reported principally based on the observations using the C-terminal fragments of NPY. Recent studies indicate an involvement of the receptor in food intake, gastrointestinal motility, cardiovascular regulation, and neuronal excitability. Very recently, Y(2) receptor selective antagonist has been developed and Y(2) receptor-deficient animals have been created. These new pharmacological tools will help to clarify the roles of this receptor in brain functions.
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Affiliation(s)
- T Kaga
- Second Department of Internal Medicine, Kobe University School of Medicine, Kobe, Japan
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25
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Taché Y, Martinez V, Million M, Wang L. Stress and the gastrointestinal tract III. Stress-related alterations of gut motor function: role of brain corticotropin-releasing factor receptors. Am J Physiol Gastrointest Liver Physiol 2001; 280:G173-7. [PMID: 11208537 DOI: 10.1152/ajpgi.2001.280.2.g173] [Citation(s) in RCA: 212] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Alterations of gastrointestinal (GI) motor function are part of the visceral responses to stress. Inhibition of gastric emptying and stimulation of colonic motor function are the commonly encountered patterns induced by various stressors. Activation of brain corticotropin-releasing factor (CRF) receptors mediates stress-related inhibition of upper GI and stimulation of lower GI motor function through interaction with different CRF receptor subtypes. CRF subtype 1 receptors are involved in the colonic and anxiogenic responses to stress and may have clinical relevance in the comorbidity of anxiety/depression and irritable bowel syndrome.
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Affiliation(s)
- Y Taché
- CURE: Digestive Diseases Research Center, Department of Veterans Affairs Greater Los Angeles Healthcare System, Bldg. 115, Rm. 203, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA.
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