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Bora RR, Prasad R, Khatib MN. Cardio-Protective Role of a Gut Hormone Obestatin: A Narrative Review. Cureus 2023; 15:e37972. [PMID: 37223200 PMCID: PMC10202687 DOI: 10.7759/cureus.37972] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 04/22/2023] [Indexed: 05/25/2023] Open
Abstract
Obestatin is a gut hormone composed of 23 amino acids that play a role in protecting the heart. It is synthesized from the same preproghrelin gut hormone gene as another gut hormone. The function and receptor of obestatin remain controversial, despite being present in various organs such as the liver, heart, mammary gland, pancreas, and more. The activity of obestatin is opposite to that of ghrelin, another hormone. The GPR-39 receptor is used by obestatin to exert its effects. Obestatin's cardioprotective role can be attributed to its ability to affect various factors, including adipose tissue, blood pressure regulation, heart, ischemia-reperfusion injury, endothelial cells, and diabetes. Because these factors are related to the cardiovascular system, modifying them via obestatin can provide cardioprotection. Furthermore, ghrelin, its antagonist hormone, regulates cardiovascular health. Diabetes mellitus, hypertension, and ischemia-reperfusion injury can all alter ghrelin/obestatin levels. Obestatin has also been shown to impact other organs, reducing weight and appetite, inhibiting food intake, and increasing adipogenesis. Obestatin has a brief half-life and is quickly degraded by proteases in the blood, liver, and kidneys after entering circulation. This article offers insights into the cardiac function of obestatin.
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Affiliation(s)
- Rajal R Bora
- Physiology, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Roshan Prasad
- Medicine and Surgery, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Mahalaqua Nazli Khatib
- Epidemiology and Public Health, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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Ghrelin and Obestatin in Adolescent Patients with Anorexia Nervosa: Is There an Association with Disordered Eating, Depression, and Obsessive-Compulsive Symptoms? PSYCHIATRY INTERNATIONAL 2022. [DOI: 10.3390/psychiatryint3030020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Anorexia nervosa (AN) is an eating disorder characterized by restrictive eating and significant weight loss. In the course of AN, changes are observed in appetite regulation, including orexigenic ghrelin and potentially anorexigenic obestatin. The study aimed to determine if any changes in serum ghrelin and obestatin levels during treatment of AN are observed, while investigating the correlations between these peptides and the severity of disturbed eating attitudes, depression, and anxiety. Thirty adolescent inpatients with AN (examined twice: before hospitalization treatment AN-BT and after treatment AN-AT) and thirty healthy age- and height-matched girls (CG) participated in the study. Anthropometric, serum ghrelin and obestatin concentrations and psychometric evaluations (Eating Attitudes Test 26 Item-EAT-26, Beck Depression Inventory-BDI, Hamilton Depression Rating Scale-HDRS, and Yale Brown Obsessive-Compulsive Scale-Y-BOCS) were performed. The study revealed significantly higher ghrelin and obestatin levels in AN-BT than in AN-AT. A trend toward lower levels during treatment provided partial normalizations. Analyzing correlations in the AN-BT vs. CG group, correlations of peptides with EAT-26, BDI, and HDRS scores were detected. These results suggest a potential role for ghrelin and obestatin in the context of defense mechanisms regulating appetite and body weight in the course of AN and in terms of psychopathological changes co-occurring with this eating disorder.
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Villarreal D, Pradhan G, Zhou Y, Xue B, Sun Y. Diverse and Complementary Effects of Ghrelin and Obestatin. Biomolecules 2022; 12:biom12040517. [PMID: 35454106 PMCID: PMC9028691 DOI: 10.3390/biom12040517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023] Open
Abstract
Ghrelin and obestatin are two “sibling proteins” encoded by the same preproghrelin gene but possess an array of diverse and complex functions. While there are ample literature documenting ghrelin’s functions, the roles of obestatin are less clear and controversial. Ghrelin and obestatin have been perceived to be antagonistic initially; however, recent studies challenge this dogma. While they have opposing effects in some systems, they function synergistically in other systems, with many functions remaining debatable. In this review, we discuss their functional relationship under three “C” categories, namely complex, complementary, and contradictory. Their functions in food intake, weight regulation, hydration, gastrointestinal motility, inflammation, and insulin secretion are complex. Their functions in pancreatic beta cells, cardiovascular, muscle, neuroprotection, cancer, and digestive system are complementary. Their functions in white adipose tissue, thermogenesis, and sleep regulation are contradictory. Overall, this review accumulates the multifaceted functions of ghrelin and obestatin under both physiological and pathological conditions, with the intent of contributing to a better understanding of these two important gut hormones.
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Affiliation(s)
- Daniel Villarreal
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
| | - Geetali Pradhan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao 266071, China;
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
| | - Yuxiang Sun
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Correspondence: ; Tel.: +1-979-862-9143
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Słupecka-Ziemilska M, Szczurek P, Boryczka M, Gajewska M, Wychowański P, Kuwahara A, Kato I, Dzięgelewska Ż, Woliński J. The effects of intra-stomach obestatin administration on intestinal contractility in neonatal piglets fed milk formula. PLoS One 2020; 15:e0230190. [PMID: 32203550 PMCID: PMC7089538 DOI: 10.1371/journal.pone.0230190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 02/24/2020] [Indexed: 12/03/2022] Open
Abstract
A 23-amino acid peptide named obestatin is derived from the ghrelin gene. The aim of the experiment was to study the effects of enteral obestatin administration for a 6-day period on intestinal contractility in piglets fed milk formula. Pigs were treated with 0.9% NaCl (group C) or varying doses of obestatin: 2 μg/kg body weight (BW) (group O2), 10 μg/kg BW (O10) or 15 μg/kg BW (O15) every 8 hours via a stomach tube. Blood was sampled for assessment of obestatin concentration. Duodenal and middle jejunum whole-thickness preparations were studied in an organ bath for isometric recording under electric field stimulation (EFS) and increasing doses of acetylcholine (ACh), and in the presence of atropine and tetrodotoxin (TTX). Additionally, the measurement of intestinal muscularis layer and the immunodetection of Muscarinic Acetylcholine Receptors (M1 and M2) were performed. In comparison to C animals, the obestatin concentration in blood plasma was significantly increased in groups O10 and O15. In both studied intestinal segments, significant increases in the frequency and amplitude of spontaneous contractions were observed in O15 and C groups. In the duodenum and middle jejunum significant differences in responsiveness to EFS (0.5, 5 and 50 Hz) were observed between the groups. The addition of 10−4 M ACh to the duodenum significantly increased the responsiveness in tissues. In contrast, in the middle jejunum a significant increase in the amplitude of contraction was observed after the addition of 10−9 and 10−6 M ACh (groups O15 and O10, respectively). Pretreatment with atropine and TTX resulted in a significant decrease in the responsiveness of the intestinal preparations from all groups, in both studied segments. The increased contractility was not dependent on the expression of muscarinic receptors. Results indicate the importance of enteral obestatin administration in the regulation of intestinal contractility in neonatal piglets.
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Affiliation(s)
- Monika Słupecka-Ziemilska
- Department of Animal Physiology, Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, Jabłonna, Poland
| | - Paulina Szczurek
- Department of Animal Nutrition and Feed Sciences, National Research Institute of Animal Production, Balice, Poland
| | - Maria Boryczka
- Department of Animal Physiology, Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, Jabłonna, Poland
| | - Małgorzata Gajewska
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Piotr Wychowański
- Department of Dental Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Atsukazu Kuwahara
- Laboratory of Physiology, Institute for Environmental Sciences & Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
| | - Ikuo Kato
- Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Japan
| | - Żaneta Dzięgelewska
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Jarosław Woliński
- Department of Animal Physiology, Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, Jabłonna, Poland
- * E-mail:
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Vancleef L, Thijs T, Baert F, Ceulemans LJ, Canovai E, Wang Q, Steensels S, Segers A, Farré R, Pirenne J, Lannoo M, Tack J, Depoortere I. Obesity Impairs Oligopeptide/Amino Acid-Induced Ghrelin Release and Smooth Muscle Contractions in the Human Proximal Stomach. Mol Nutr Food Res 2018; 62. [DOI: 10.1002/mnfr.201700804] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/29/2017] [Indexed: 01/11/2023]
Affiliation(s)
- Laurien Vancleef
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Theo Thijs
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Florence Baert
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Laurens J. Ceulemans
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Emilio Canovai
- Abdominal Transplant Surgery; University Hospital Gasthuisberg; Leuven Belgium
| | - Qiaoling Wang
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Sandra Steensels
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Anneleen Segers
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Ricard Farré
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Jacques Pirenne
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Matthias Lannoo
- Abdominal Surgery; University Hospital Gasthuisberg; Belgium
| | - Jan Tack
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
| | - Inge Depoortere
- Translational Research Center for Gastrointestinal Disorders; Department of Clinical & Experimental Medicine; University of Leuven; Leuven Belgium
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Green BD, Grieve DJ. Biochemical properties and biological actions of obestatin and its relevence in type 2 diabetes. Peptides 2018; 100:249-259. [PMID: 29412827 DOI: 10.1016/j.peptides.2017.12.006] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/15/2022]
Abstract
Obestatin was initially discovered in rat stomach extract, and although it is principally produced in the gastric mucosa, it can be found throughout the gastrointestinal tract. This 23-amino acid C-terminally amidated peptide is derived from preproghrelin and has been ascribed a wide range of metabolic effects relevant to type 2 diabetes. Obestatin reportedly inhibits gastrointestinal motility, reduces food intake and lowers body weight and improves lipid metabolism. Furthermore, it appears to exert actions on the pancreatic β-cell, most notably increasing β-cell mass and upregulating genes associated with insulin production and β-cell regeneration, with relevance to type 2 diabetes. It is becoming evident that obestatin also exerts pleiotropic effects on the cardiovascular system, possibly modulating blood pressure, endothelial function and triggering cardioprotective mechanisms, which may be important in determining cardiovascular outcomes in type 2 diabetes. Furthermore, it seems that like other gut peptides obestatin has neuroprotective properties. This review examines the biochemical properties of the obestatin peptide (its structure, sequence, stability and distribution) and the candidate receptors through which it may act. It provides a balanced examination of the reported pancreatic and extrapancreatic actions of obestatin and evaluates its potential relevance with respect to diabetes therapy, together with discussion of direct evidence linking alterations in obestatin signalling with obesity/diabetes and other diseases.
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Affiliation(s)
- Brian D Green
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5BN, UK.
| | - David J Grieve
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, BT9 7AE, UK
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Słupecka M, Grzesiak P, Kwiatkowski J, Gajewska M, Kuwahara A, Kato I, Woliński J. The influence of enteral obestatin administration to suckling rats on intestinal contractility. Gen Comp Endocrinol 2017; 248:69-78. [PMID: 28212895 DOI: 10.1016/j.ygcen.2017.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 01/24/2017] [Accepted: 02/13/2017] [Indexed: 12/13/2022]
Abstract
This study investigated the effect of enteral administration of obestatin on the contractility of whole-thickness preparations of duodenum and middle jejunum, as well as on the morphology of the enteric nervous system (ENS). Suckling rats were assigned to 3 groups (n=12) treated with: C-saline solution; LO-obestatin (125nmol/kgb.wt); HO-obestatin (250nmol/kgb.wt). Saline solution or obestatin were administered twice daily, from the 14th to the 21st day of life. Sections were studied in an organ bath, for isometric recording in the presence of acetylocholine (ACh), atropine (ATR) and tetradotoxin (TTX). Thickness of intestinal muscularis layer, the number of interstitial cells of Cajal (ICC) were measured in the paraffin sections. The immunodetection of Muscarinic Acetylocholine Receptor 2 (M2 receptor) was performed in the intestinal segments. In both intestinal segments HO treatment decreased the amplitude of spontaneous contraction compared to that observed in the C group. In the middle jejunum, the LO treatment also decreased the amplitude. TTX and ATR had no effect on amplitude of spontaneous contraction in the jejunum of LO and HO-treated animals. Compared to the C group, duodenal sections from HO animals and middle jejunum sections from LO and HO groups displayed a lower amplitude in response to ACh and EFS evoked contraction. An increase in the thickness of the muscularis layer was observed in the duodenum of LO and HO groups whereas the number ICC did not change significantly after treatment with obestatin. Moreover, the enteral administration of obestatin did not effect significantly on the cytoplasmic expression of M2 receptor in the jejunum. Our study demonstrated that enteral administration of obestatin to suckling rats influences small intestine contractility in the segment specific manner.
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Affiliation(s)
- M Słupecka
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland.
| | - P Grzesiak
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
| | - J Kwiatkowski
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
| | - M Gajewska
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - A Kuwahara
- Laboratory of Physiology, Institute for Environmental Sciences and Graduate School of Nutritional and Enviromental Science, University of Shizuoka, Japan
| | - I Kato
- Department of Medical Biochemistry, Kobe Pharmaceutical University, Japan
| | - J Woliński
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
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8
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Kołodziejski PA, Pruszyńska-Oszmałek E, Strowski MZ, Nowak KW. Long-term obestatin treatment of mice type 2 diabetes increases insulin sensitivity and improves liver function. Endocrine 2017; 56:538-550. [PMID: 28477305 DOI: 10.1007/s12020-017-1309-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/19/2017] [Indexed: 01/02/2023]
Abstract
PURPOSE Obestatin and ghrelin are peptides encoded by the preproghrelin gene. Obestatin inhibits food intake, in addition to regulation of glucose and lipid metabolism. Here, we test the ability of obestatin at improving metabolic control and liver function in type 2 diabetic animals (type 2 diabetes mellitus). METHODS The effects of chronic obestatin treatment of mice with experimentally induced type 2 diabetes mellitus on serum levels of glucose and lipids, and insulin sensitivity are characterized. In addition, alterations of hepatic lipid and glycogen contents are evaluated. RESULTS Obestatin reduced body weight and decreased serum glucose, fructosamine, and β-hydroxybutyrate levels, as well as total and low-density lipoprotein fractions of cholesterol. In addition, obestatin increased high-density lipoproteins cholesterol levels and enhanced insulin sensitivity in mice with type 2 diabetes mellitus. Moreover, obestatin diminished liver mass, hepatic triglycerides and cholesterol contents, while glycogen content was higher in livers of healthy and mice with type 2 diabetes mellitus treated with obestatin. These changes were accompanied by reduction of increased alanine aminotransferase, aspartate aminotransferase, and gamma glutamyl transpeptidase in T2DM mice with type 2 diabetes mellitus. Obestatin increased adiponectin levels and reduced leptin concentration. Obestatin influenced the expression of genes involved in lipid and carbohydrate metabolism by increasing Fabp5 and decreasing G6pc, Pepck, Fgf21 mRNA in the liver. Obestatin increased both, AKT and AMPK phosphorylation, and sirtuin 1 (SIRT1) protein levels as well as mRNA expression in the liver. CONCLUSION Obestatin improves metabolic abnormalities in type 2 diabetes mellitus, restores hepatic lipid contents and decreases hepatic enzymes. Therefore, obestatin could potentially have a therapeutic relevance in treating of insulin resistance and metabolic dysfunctions in type 2 diabetes mellitus.
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Affiliation(s)
- Paweł A Kołodziejski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland.
| | - Ewa Pruszyńska-Oszmałek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland
| | - Mathias Z Strowski
- Department of Hepatology and Gastroenterology & the Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, 13353, Berlin, Germany
- Park-Klinik Weissensee, Internal Medicine - Gastroenterology, Berlin, 13086, Germany
| | - Krzysztof W Nowak
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland
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Nagaraj S, Manjappara UV. Studies on the influence of CCK-8 on the ability of obestatin to reduce food intake, gain in body weight and related lipid parameters. Biochimie 2016; 125:126-30. [DOI: 10.1016/j.biochi.2016.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/21/2016] [Indexed: 10/22/2022]
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Cowan E, Burch KJ, Green BD, Grieve DJ. Obestatin as a key regulator of metabolism and cardiovascular function with emerging therapeutic potential for diabetes. Br J Pharmacol 2016; 173:2165-81. [PMID: 27111465 DOI: 10.1111/bph.13502] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/05/2016] [Accepted: 04/15/2016] [Indexed: 01/01/2023] Open
Abstract
Obestatin is a 23-amino acid C-terminally amidated gastrointestinal peptide derived from preproghrelin and which forms an α helix. Although obestatin has a short biological half-life and is rapidly degraded, it is proposed to exert wide-ranging pathophysiological actions. Whilst the precise nature of many of its effects is unclear, accumulating evidence supports positive actions on both metabolism and cardiovascular function. For example, obestatin has been reported to inhibit food and water intake, body weight gain and gastrointestinal motility and also to mediate promotion of cell survival and prevention of apoptosis. Obestatin-induced increases in beta cell mass, enhanced adipogenesis and improved lipid metabolism have been noted along with up-regulation of genes associated with beta cell regeneration, insulin production and adipogenesis. Furthermore, human circulating obestatin levels generally demonstrate an inverse association with obesity and diabetes, whilst the peptide has been shown to confer protective metabolic effects in experimental diabetes, suggesting that it may hold therapeutic potential in this setting. Obestatin also appears to be involved in blood pressure regulation and to exert beneficial effects on endothelial function, with experimental studies indicating that it may also promote cardioprotective actions against, for example, ischaemia-reperfusion injury. This review will present a critical appraisal of the expanding obestatin research area and discuss the emerging therapeutic potential of this peptide for both metabolic and cardiovascular complications of diabetes.
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Affiliation(s)
- Elaine Cowan
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Belfast, UK
| | - Kerry J Burch
- Queen's University Belfast, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, UK
| | - Brian D Green
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Belfast, UK
| | - David J Grieve
- Queen's University Belfast, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, UK
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11
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Avau B, Rotondo A, Thijs T, Andrews CN, Janssen P, Tack J, Depoortere I. Targeting extra-oral bitter taste receptors modulates gastrointestinal motility with effects on satiation. Sci Rep 2015; 5:15985. [PMID: 26541810 PMCID: PMC4635351 DOI: 10.1038/srep15985] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 10/06/2015] [Indexed: 01/01/2023] Open
Abstract
Bitter taste receptors (TAS2Rs) are present in extra-oral tissues, including gut endocrine cells. This study explored the presence and mechanism of action of TAS2R agonists on gut smooth muscle in vitro and investigated functional effects of intra-gastric administration of TAS2R agonists on gastric motility and satiation. TAS2Rs and taste signalling elements were expressed in smooth muscle tissue along the mouse gut and in human gastric smooth muscle cells (hGSMC). Bitter tastants induced concentration and region-dependent contractility changes in mouse intestinal muscle strips. Contractions induced by denatonium benzoate (DB) in gastric fundus were mediated via increases in intracellular Ca2+ release and extracellular Ca2+-influx, partially masked by a hyperpolarizing K+-efflux. Intra-gastric administration of DB in mice induced a TAS2R-dependent delay in gastric emptying. In hGSMC, bitter compounds evoked Ca2+-rises and increased ERK-phosphorylation. Healthy volunteers showed an impaired fundic relaxation in response to nutrient infusion and a decreased nutrient volume tolerance and increased satiation during an oral nutrient challenge test after intra-gastric DB administration. These findings suggest a potential role for intestinal TAS2Rs as therapeutic targets to alter gastrointestinal motility and hence to interfere with hunger signalling.
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Affiliation(s)
- Bert Avau
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Alessandra Rotondo
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Theo Thijs
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Christopher N Andrews
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Pieter Janssen
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Jan Tack
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Inge Depoortere
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
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12
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Słupecka M, Pierzynowski SG, Kuwahara A, Kato I, Woliński J. Age-dependent effect of obestatin on intestinal contractility in Wistar rats. Gen Comp Endocrinol 2014; 208:109-15. [PMID: 25193331 DOI: 10.1016/j.ygcen.2014.08.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/28/2014] [Accepted: 08/10/2014] [Indexed: 11/26/2022]
Abstract
Obestatin is a 23-amino acid peptide encoded by the ghrelin gene. We have investigated the effect of obestatin on intestinal contractility in rats ranging from the suckling period till adolescence. Duodenal and middle jejunum whole-thickness preparations from neonatal and adult rats were studied in an organ bath, for isometric recording under treatment with obestatin (1μmolL(-1)) in the presence of acetylocholine (ACh), atropine and tetradotoxin (TTX). Both the EFS and ACh-stimulated contractile response, as well as spontaneous contractile activity is age-dependent and specific for the segment of jejunum. Except for the middle jejunum of 7day old rats, treatment with obestatin caused a significant TTX-sensitive increase in the amplitude of EFS-stimulated off-contraction of both intestinal segments studied. Following injection of obestatin, the amplitude of spontaneous contraction in the duodenum increased in 7day old rats. In the middle jejunum, treatment with obestatin significantly increased both the amplitude and frequency of spontaneous contraction in rats till the 28th day of life, whereas in adult rats the observed effect of obestatin was the opposite (P<0.001 and P<0.0001, respectively). The effects of treatment with obestatin on stimulation with increasing doses of ACh were only observed in the preparations from suckling rats. ACh-stimulated contractility in the duodenum was decreased while in the middle jejunum the observed effect was opposite. These results indicate the importance of peripheral obestatin in the cholinergic control of intestinal contractility in both neonatal and adult rats.
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Affiliation(s)
- M Słupecka
- Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland.
| | - S G Pierzynowski
- Department of Biology, Lund University, Lund, Sweden; Department of Medical Biology, Institute of Agricultural Medicine, Lublin, Poland
| | - A Kuwahara
- Laboratory of Physiology, Institute for Environmental Sciences & Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
| | - I Kato
- Department of Bioorganic Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan
| | - J Woliński
- Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
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Laermans J, Broers C, Beckers K, Vancleef L, Steensels S, Thijs T, Tack J, Depoortere I. Shifting the circadian rhythm of feeding in mice induces gastrointestinal, metabolic and immune alterations which are influenced by ghrelin and the core clock gene Bmal1. PLoS One 2014; 9:e110176. [PMID: 25329803 PMCID: PMC4199674 DOI: 10.1371/journal.pone.0110176] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/12/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In our 24-hour society, an increasing number of people are required to be awake and active at night. As a result, the circadian rhythm of feeding is seriously compromised. To mimic this, we subjected mice to restricted feeding (RF), a paradigm in which food availability is limited to short and unusual times of day. RF induces a food-anticipatory increase in the levels of the hunger hormone ghrelin. We aimed to investigate whether ghrelin triggers the changes in body weight and gastric emptying that occur during RF. Moreover, the effect of genetic deletion of the core clock gene Bmal1 on these physiological adaptations was studied. METHODS Wild-type, ghrelin receptor knockout and Bmal1 knockout mice were fed ad libitum or put on RF with a normal or high-fat diet (HFD). Plasma ghrelin levels were measured by radioimmunoassay. Gastric contractility was studied in vitro in muscle strips and in vivo (13C breath test). Cytokine mRNA expression was quantified and infiltration of immune cells was assessed histologically. RESULTS The food-anticipatory increase in plasma ghrelin levels induced by RF with normal chow was abolished in HFD-fed mice. During RF, body weight restoration was facilitated by ghrelin and Bmal1. RF altered cytokine mRNA expression levels and triggered contractility changes resulting in an accelerated gastric emptying, independent from ghrelin signaling. During RF with a HFD, Bmal1 enhanced neutrophil recruitment to the stomach, increased gastric IL-1α expression and promoted gastric contractility changes. CONCLUSIONS This is the first study demonstrating that ghrelin and Bmal1 regulate the extent of body weight restoration during RF, whereas Bmal1 controls the type of inflammatory infiltrate and contractility changes in the stomach. Disrupting the circadian rhythm of feeding induces a variety of diet-dependent metabolic, immune and gastrointestinal alterations, which may explain the higher prevalence of obesity and immune-related gastrointestinal disorders among shift workers.
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Affiliation(s)
- Jorien Laermans
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Charlotte Broers
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Kelly Beckers
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Laurien Vancleef
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Sandra Steensels
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Theo Thijs
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Jan Tack
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
| | - Inge Depoortere
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium
- * E-mail:
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Squecco R, Garella R, Francini F, Baccari MC. Influence of obestatin on the gastric longitudinal smooth muscle from mice: mechanical and electrophysiological studies. Am J Physiol Gastrointest Liver Physiol 2013; 305:G628-37. [PMID: 23989009 DOI: 10.1152/ajpgi.00059.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Obestatin is a hormone released from the stomach deriving from the same peptide precursor as ghrelin. It is known to act as an anorectic hormone decreasing food intake, but contrasting results have been reported about the effects of obestatin on gastrointestinal motility. The aim of the present study was to investigate whether this peptide may act on the gastric longitudinal smooth muscle by using a combined mechanical and electrophysiological approach. When fundal strips from mice were mounted in organ baths for isometric recording of the mechanical activity, obestatin caused a tetrodotoxin-insensitive decrease of the basal tension and a reduction in amplitude of the neurally induced cholinergic contractile responses, even in the presence of the nitric oxide synthesis inhibitor N(G)-nitro-l-arginine. Obestatin reduced the amplitude of the response to the ganglionic stimulating agent dimethylphenyl piperazinium iodide but did not influence that to methacholine. In nonadrenergic, noncholinergic conditions, obestatin still decreased the basal tension of the preparations without influencing the neurally induced relaxant responses. For comparison, in circular fundal strips, obestatin had no effects. Notably, in the longitudinal antral ones, obestatin only caused a decrease of the basal tension. Electrophysiological experiments, performed by a single microelectrode inserted in a gastric longitudinal smooth muscle cell, showed that obestatin had similar effects in fundal and antral preparations: it decreased the resting specific membrane conductance, inhibited Ca(2+) currents, and positively shifted their voltage threshold of activation. In conclusion, the present results indicate that obestatin influences gastric smooth muscle exerting site-specific effects.
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Affiliation(s)
- Roberta Squecco
- Dipartimento di Medicina Sperimentale e Clinica, Sezione di Scienze Fisiologiche, Università degli Studi, Firenze, Viale Morgagni 63, 50134, Italy.
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16
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Song Z, Everaert N, Wang Y, Decuypere E, Buyse J. The endocrine control of energy homeostasis in chickens. Gen Comp Endocrinol 2013; 190:112-7. [PMID: 23707377 DOI: 10.1016/j.ygcen.2013.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 01/02/2023]
Abstract
Energy homeostasis (balance) depends on the relationship between the amount of consumed feed energy and energy expenditure. Coordination of energy expenditure and feed intake (appetite) is necessary for the regulation of body composition. The hypothalamus integrates peripheral and central signals to generate satiety or hunger. Birds and mammals utilize common signaling molecules but some molecules possess different/opposite functions. If relevant, particular differences with the mammalian regulatory system are highlighted in this review. For example, obestatin had no significant effect on feed intake of chicks, but it was claimed to decrease food intake in mammalian species. Ghrelin displayed appetite-stimulating effects in mammals but appetite-decreasing effects in birds. Recently, the function of the hypothalamic AMPK signaling pathway on feed intake regulation has received considerable attention in poultry. Alpha-lipoic acid might exert its appetite-decreasing effect by the AMPK signaling pathway. This review discusses the central regulation of energy homeostasis, role of (an)orexigenic peptides, effect of feed deprivation on hypothalamic neuropeptide gene expression and provides a model for involvement of AMPK in the regulation of avian energy balance.
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Affiliation(s)
- Zhigang Song
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, PR China
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17
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Atalayer D, Gibson C, Konopacka A, Geliebter A. Ghrelin and eating disorders. Prog Neuropsychopharmacol Biol Psychiatry 2013; 40:70-82. [PMID: 22960103 PMCID: PMC3522761 DOI: 10.1016/j.pnpbp.2012.08.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 08/03/2012] [Accepted: 08/19/2012] [Indexed: 12/25/2022]
Abstract
There is growing evidence supporting a multifactorial etiology that includes genetic, neurochemical, and physiological components for eating disorders above and beyond the more conventional theories based on psychological and sociocultural factors. Ghrelin is one of the key gut signals associated with appetite, and the only known circulating hormone that triggers a positive energy balance by stimulating food intake. This review summarizes recent findings and several conflicting reports on ghrelin in eating disorders. Understanding these findings and inconsistencies may help in developing new methods to prevent and treat patients with these disorders.
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Affiliation(s)
- Deniz Atalayer
- Department of Medicine, New York Obesity Research and Nutrition Center, St. Luke's-Roosevelt Hospital, New York, NY, USA.
| | - Charlisa Gibson
- Department of Medicine, New York Obesity Research and Nutrition Center, St. Luke’s-Roosevelt Hospital, New York NY, USA
| | - Alexandra Konopacka
- Department of Medicine, New York Obesity Research and Nutrition Center, St. Luke’s-Roosevelt Hospital, New York NY, USA
| | - Allan Geliebter
- Department of Medicine, New York Obesity Research and Nutrition Center, St. Luke’s-Roosevelt Hospital, New York NY, USA,Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA,Department of Psychology, Touro College, New York, NY, USA
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Zhang JV, Li L, Huang Q, Ren PG. Obestatin receptor in energy homeostasis and obesity pathogenesis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:89-107. [PMID: 23317783 DOI: 10.1016/b978-0-12-386933-3.00003-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Based on the bioinformatic prediction, Zhang and colleagues discovered obestatin, a new 23-amino acid hormone from rat stomach extract encoded by the ghrelin gene. Obestatin is present not only in the gastrointestinal tract, but also in the spleen, mammary gland, breast milk, and plasma. Obestatin appears to function as part of a complex gut-brain network whereby hormones and substances from the stomach, intestine and the brain about satiety or hunger. Given the current research regarding the effects of obestatin and its possible cognate receptor(s), this chapter provides the latest review of the physiological and pathological characteristics of this hormone and its possible receptor(s) in energy homeostasis and obesity.
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Affiliation(s)
- Jian V Zhang
- Research Center for Gene and Cell Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advance Technology, Chinese Academy of Sciences, Shenzhen, China
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Chopin LK, Seim I, Walpole CM, Herington AC. The ghrelin axis--does it have an appetite for cancer progression? Endocr Rev 2012; 33:849-91. [PMID: 22826465 DOI: 10.1210/er.2011-1007] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk; however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation, and angiogenesis; however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression.
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Affiliation(s)
- Lisa K Chopin
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Queensland University of Technology and Australian Prostate Cancer Research Centre-Queensland, Brisbane, Queensland 4001, Australia.
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20
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GI functions of GPR39: novel biology. Curr Opin Pharmacol 2012; 12:647-52. [PMID: 22884904 DOI: 10.1016/j.coph.2012.07.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/24/2012] [Accepted: 07/27/2012] [Indexed: 01/20/2023]
Abstract
GPR39 is an orphan GPCR receptor belonging to the ghrelin/motilin receptor subfamily. The receptor is constitutively active and Zn(2+) is a physiological agonist of GPR39. The receptor is emerging as an important regulator of gastrointestinal motility and secretion. Although GPR39 does not seem to be involved in the regulation of food intake, contradictory results are available on the role of GPR39 in the regulation of body weight. A well-established stimulatory role for GPR39 has been defined in insulin secretion which makes the receptor an attractive target for the treatment of type 1 or 2 diabetes. GPR39 signaling also inhibits apoptosis and mediates neural synaptic signaling. Novel ligands of GPR39 are warranted to reveal the main physiological role of this receptor.
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Song Z, Verhulst PJ, Ansari Z, Thijs T, Depoortere I, Everaert N, Decuypere E, Buyse J. Peripheral “chicken” obestatin administration does not affect feed intake and gut muscle contractility of meat-type and layer-type chicks (Gallus gallus domesticus). ACTA ACUST UNITED AC 2012; 177:60-7. [DOI: 10.1016/j.regpep.2012.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 04/15/2012] [Accepted: 04/25/2012] [Indexed: 11/25/2022]
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Abstract
The migrating motor complex (MMC) is a cyclic, recurring motility pattern that occurs in the stomach and small bowel during fasting; it is interrupted by feeding. The MMC is present in the gastrointestinal tract of many species, including humans. The complex can be subdivided into four phases, of which phase III is the most active, with a burst of contractions originating from the antrum or duodenum and migrating distally. Control of the MMC is complex. Phase III of the MMC with an antral origin can be induced in humans through intravenous administration of motilin, erythromycin or ghrelin, whereas administration of serotonin or somatostatin induces phase III activity with duodenal origin. The role of the vagus nerve in control of the MMC seems to be restricted to the stomach, as vagotomy abolishes the motor activity in the stomach, but leaves the periodic activity in the small bowel intact. The physiological role of the MMC is incompletely understood, but its absence has been associated with gastroparesis, intestinal pseudo-obstruction and small intestinal bacterial overgrowth. Measuring the motility of the gastrointestinal tract can be important for the diagnosis of gastrointestinal disorders. In this Review we summarize current knowledge of the MMC, especially its role in health and disease.
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Muccioli G, Lorenzi T, Lorenzi M, Ghè C, Arnoletti E, Raso GM, Castellucci M, Gualillo O, Meli R. Beyond the metabolic role of ghrelin: a new player in the regulation of reproductive function. Peptides 2011; 32:2514-21. [PMID: 22074955 DOI: 10.1016/j.peptides.2011.10.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 10/23/2011] [Accepted: 10/23/2011] [Indexed: 11/30/2022]
Abstract
Ghrelin is a gastric peptide, discovered by Kojima et al. (1999) [55] as a result of the search for an endogenous ligand interacting with the "orphan receptor" GHS-R1a (growth hormone secretagogue receptor type 1a). Ghrelin is composed of 28 aminoacids and is produced mostly by specific cells of the stomach, by the hypothalamus and hypophysis, even if its presence, as well as that of its receptors, has been demonstrated in many other tissues, not least in gonads. Ghrelin potently stimulates GH release and participates in the regulation of energy homeostasis, increasing food intake, decreasing energy output and exerting a lipogenetic effect. Furthermore, ghrelin influences the secretion and motility of the gastrointestinal tract, especially of the stomach, and, above all, profoundly affects pancreatic functions. Despite of these previously envisaged activities, it has recently been hypothesized that ghrelin regulates several aspects of reproductive physiology and pathology. In conclusion, ghrelin not only cooperates with other neuroendocrine factors, such as leptin, in the modulation of energy homeostasis, but also has a crucial role in the regulation of the hypothalamic-pituitary gonadal axis. In the current review we summarize the main targets of this gastric peptide, especially focusing on the reproductive system.
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Affiliation(s)
- Giampiero Muccioli
- Department of Drug Science and Technology, Division of Medical Pharmacology, University of Torino, Via P. Giuria 13, 10125 Torino, Italy
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25
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Seim I, Walpole C, Amorim L, Josh P, Herington A, Chopin L. The expanding roles of the ghrelin-gene derived peptide obestatin in health and disease. Mol Cell Endocrinol 2011; 340:111-7. [PMID: 21459124 DOI: 10.1016/j.mce.2011.03.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/23/2011] [Accepted: 03/25/2011] [Indexed: 01/18/2023]
Abstract
Obestatin is a 23 amino acid, ghrelin gene-derived peptide hormone produced in the stomach and a range of other tissues throughout the body. While it was initially reported that obestatin opposed the actions of ghrelin with regards to appetite and food intake, it is now clear that obestatin is not an endogenous ghrelin antagonist, but it is a multi-functional peptide hormone in its own right. In this review we will discuss the controversies associated with the discovery of obestatin and explore emerging central and peripheral roles of obestatin, which includes adipogenesis, pancreatic homeostasis and cancer.
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Affiliation(s)
- Inge Seim
- Queensland University of Technology, Queensland, Brisbane, Australia
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26
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Verhulst PJ, Lintermans A, Janssen S, Loeckx D, Himmelreich U, Buyse J, Tack J, Depoortere I. GPR39, a receptor of the ghrelin receptor family, plays a role in the regulation of glucose homeostasis in a mouse model of early onset diet-induced obesity. J Neuroendocrinol 2011; 23:490-500. [PMID: 21470317 DOI: 10.1111/j.1365-2826.2011.02132.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
GPR39, which may function as a Zn(2+) sensor, is a member of the G protein-coupled receptor family that also includes the receptor for the hunger hormone ghrelin. The down-regulation of GPR39 mRNA in adipose tissue of obese type 2 diabetic patients suggests that GPR39 may contribute to the pathogenesis of the disease. The present study aimed to investigate the role of GPR39 in the regulation of energy balance and glucose homeostasis in wild-type (GPR39(+/+) ) and GPR39 knockout mice (GPR39(-/-) ) with obesity-related type 2 diabetes. GPR39 mRNA levels in adipose tissue of fasted GPR39(+/+) mice fed a high-fat diet (HFD) for 30 weeks were reduced and correlated positively with blood glucose levels. Body weight, fat percentage and energy intake were increased in the HFD group but did not differ between both genotypes. Within the HFD group, blood glucose levels were lower in GPR39(-/-) than in GPR39(+/+) mice, despite significant reductions in prandial plasma insulin levels. The latter may not be a result of changes in β-cell hyperplasia because immunohistochemical staining of pancreata of mice on a HFD showed no differences between genotypes. The lower blood glucose levels may involve alterations in insulin sensitivity as revealed by glucose tolerance tests and respiratory quotient measurements that showed a preference of obese GPR39(-/-) mice for the use of carbohydrates as metabolic fuel. The increase in plasma ghrelin levels in GPR39(-/-) mice fed a HFD may contribute to the alterations in glucose homeostasis, whereas changes in gastric emptying or intestinal Zn(2+) absorption are not involved. The results obtained in the present study suggest that GPR39 plays a role in the pathogenesis of obesity-related type 2 diabetes by affecting the regulation of glucose homeostasis.
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MESH Headings
- Age of Onset
- Animals
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diet/adverse effects
- Diet, Atherogenic
- Disease Models, Animal
- Genetic Predisposition to Disease
- Glucose/metabolism
- Homeostasis/genetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Multigene Family/physiology
- Obesity/epidemiology
- Obesity/etiology
- Obesity/genetics
- Obesity/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Receptors, Ghrelin/genetics
- Receptors, Ghrelin/physiology
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Affiliation(s)
- P J Verhulst
- Department of Pathophysiology, Translational Research Center for Gastrointestinal Disorders, Catholic University of Leuven, Leuven, Belgium
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Qian Q, Chen W, Guo C, Wu W, Qian W, Li S. Xiao-Ban-Xia-Tang inhibits cisplatin-induced pica by down regulating obestatin in rats. JOURNAL OF ETHNOPHARMACOLOGY 2011; 135:186-193. [PMID: 21396996 DOI: 10.1016/j.jep.2011.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/22/2011] [Accepted: 03/03/2011] [Indexed: 05/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Xiao-Ban-Xia-Tang (XBXT), a traditional Chinese herbal medicine, has been used in China for more than 2000 years, and proved to be effective in various cases of vomiting in the clinic. OBJECTIVE To investigate the inhibitive effect of XBXT on cisplatin-induced pica behaviour and its effective mechanism on obestatin, CCK and CGRP in the pica model of rat. MATERIALS AND METHODS The inhibitive effect of XBXT was investigated in the pica model of rats induced by cisplatin (3mg kg(-1), i.p.) in 72h observation, the expression of obestatin in the area postrema and ileum was measured by immunohistochemistry and PCR, and the levels of CCK and CGRP in blood were measured by Elisa. RESULTS The weight of kaolin eaten in rats induced by cisplatin was significantly reduced by pretreatment with XBXT in a dose-dependent manner during the 0-24h and 24-72h periods (P<0.05). XBXT exhibited effective dose-dependent (P<0.05) inhibition on the increase of expression levels of obestatin in both the ileum and area postrema, and markedly suppressed the increase levels of CCK and CGRP in blood induced by cisplatin in a dose-dependent manner (P<0.05). CONCLUSIONS XBXT has good activity against cisplatin-induced eating kaolin in rats possibly by inhibiting central or peripheral increase of obestatin, or the levels of CCK and CGRP in blood.
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Affiliation(s)
- Qiuhai Qian
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan 250011, Shandong, China.
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Sanger GJ, Hellström PM, Näslund E. The hungry stomach: physiology, disease, and drug development opportunities. Front Pharmacol 2011; 1:145. [PMID: 21927604 PMCID: PMC3174087 DOI: 10.3389/fphar.2010.00145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 12/22/2010] [Indexed: 01/28/2023] Open
Abstract
During hunger, a series of high-amplitude contractions of the stomach and small intestine (phase III), which form part of a cycle of quiescence and contractions (known as the migrating motor complex, MMC), play a "housekeeping" role prior to the next meal, and may contribute toward the development of hunger. Several gastrointestinal (GI) hormones are associated with phase III MMC activity, but currently the most prominent is motilin, thought to at least partly mediate phase III contractions of the gastric MMC. Additional GI endocrine and neuronal systems play even more powerful roles in the development of hunger. In particular, the ghrelin-precursor gene is proving to have a complex physiology, giving rise to three different products: ghrelin itself, which is formed from a post-translational modification of des-acyl-ghrelin, and obestatin. The receptors acted on by des-acyl-ghrelin and by obestatin are currently unknown but both these peptides seem able to exert actions which oppose that of ghrelin, either indirectly or directly. An increased understanding of the actions of these peptides is helping to unravel a number of different eating disorders and providing opportunities for the discovery of new drugs to regulate dysfunctional gastric behaviors and appetite. To date, ghrelin and motilin receptor agonists and antagonists have been described. The most advanced are compounds which activate the ghrelin and motilin receptors which are being progressed for disorders associated with gastric hypomotility.
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Affiliation(s)
- Gareth J. Sanger
- Wingate Institute of Neurogastroenterology, Barts and The London School of Medicine and Dentistry, Queen Mary University of LondonLondon, UK
| | - Per M. Hellström
- Department of Medical Sciences, Uppsala UniversityUppsala, Sweden
| | - Erik Näslund
- Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska InstitutetStockholm, Sweden
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Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying. Proc Natl Acad Sci U S A 2011; 108:2094-9. [PMID: 21245306 DOI: 10.1073/pnas.1011508108] [Citation(s) in RCA: 247] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Ghrelin is a hunger hormone with gastroprokinetic properties but the factors controlling ghrelin secretion from the stomach are unknown. Bitter taste receptors (T2R) and the gustatory G proteins, α-gustducin (gust) and α-transducin, are expressed in the gut and are involved in the chemosensation of nutrients. This study aimed to investigate whether T2R-agonists affect (i) ghrelin release via α-gustducin and (ii) food intake and gastric emptying via the release of ghrelin. The mouse stomach contains two ghrelin cell populations: cells containing octanoyl and desoctanoyl ghrelin, which were colocalized with α-gustducin and α-transducin, and cells staining for desoctanoyl ghrelin. Gavage of T2R-agonists increased plasma octanoyl ghrelin levels in WT mice but the effect was partially blunted in gust(-/-) mice. Intragastric administration of T2R-agonists increased food intake during the first 30 min in WT but not in gust(-/-) and ghrelin receptor knockout mice. This increase was accompanied by an increase in the mRNA expression of agouti-related peptide in the hypothalamus of WT but not of gust(-/-) mice. The temporary increase in food intake was followed by a prolonged decrease (next 4 h), which correlated with an inhibition of gastric emptying. The delay in emptying, which was partially counteracted by ghrelin, was not mediated by cholecystokinin and GLP-1 but involved a direct inhibitory effect of T2R-agonists on gastric contractility. This study is unique in providing functional evidence that activation of bitter taste receptors stimulates ghrelin secretion. Modulation of endogenous ghrelin levels by tastants may provide novel therapeutic applications for the treatment of weight -and gastrointestinal motility disorders.
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30
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Popovics P, Stewart AJ. GPR39: a Zn(2+)-activated G protein-coupled receptor that regulates pancreatic, gastrointestinal and neuronal functions. Cell Mol Life Sci 2011; 68:85-95. [PMID: 20812023 PMCID: PMC11114682 DOI: 10.1007/s00018-010-0517-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 08/16/2010] [Accepted: 08/17/2010] [Indexed: 10/19/2022]
Abstract
GPR39 is a vertebrate G protein-coupled receptor related to the ghrelin/neurotensin receptor subfamily. The receptor is expressed in a range of tissues including the pancreas, gut/gastrointestinal tract, liver, kidney and in some regions of the brain. GPR39 was initially thought to be the cognitive receptor for the peptide hormone, obestatin. However, subsequent in vitro studies have failed to demonstrate binding of this peptide to the receptor. Zn(2+) has been shown to be a potent stimulator of GPR39 activity via the Gα(q), Gα(12/13) and Gα(s) pathways. The potency and specificity of Zn(2+) in activating GPR39 suggest it to be a physiologically important agonist. GPR39 is now emerging as an important transducer of autocrine and paracrine Zn(2+) signals, impacting upon cellular processes such as insulin secretion, gastric emptying, neurotransmission and epithelial repair. This review focuses on the molecular, structural and biological properties of GPR39 and its various physiological functions.
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Affiliation(s)
- Petra Popovics
- School of Medicine, University of St Andrews, Medical and Biological Sciences Building, St Andrews, Fife KY16 9TF UK
| | - Alan J. Stewart
- School of Medicine, University of St Andrews, Medical and Biological Sciences Building, St Andrews, Fife KY16 9TF UK
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Tissue distribution and effects of fasting and obesity on the ghrelin axis in mice. ACTA ACUST UNITED AC 2010; 163:62-73. [DOI: 10.1016/j.regpep.2010.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 03/05/2010] [Accepted: 03/22/2010] [Indexed: 11/21/2022]
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Chen CY, Doong ML, Li CP, Liaw WJ, Lee HF, Chang FY, Lin HC, Lee SD. A novel simultaneous measurement method to assess the influence of intracerebroventricular obestatin on colonic motility and secretion in conscious rats. Peptides 2010; 31:1113-7. [PMID: 20338205 DOI: 10.1016/j.peptides.2010.03.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 03/17/2010] [Accepted: 03/17/2010] [Indexed: 12/14/2022]
Abstract
Obestatin, a novel putative 23-amino acid peptide, is derived from mammalian preproghrelin gene via a bioinformatics approach. Although obestatin regulates thirst, sleep, memory, anxiety, activates cortical neurons in the brain and stimulate proliferation of retinal pigment epithelial cells, there is no study to explore its central impacts on the lower gut motility and secretion. We investigated the influence of intracerebroventricular (ICV) injection of obestatin on rat colonic motor and secretory functions. Colonic transit time, fecal pellet output and fecal content were assessed in freely fed, conscious rats, which were implanted with ICV and colonic catheters chronically. Human/rat corticotropin-releasing factor (h/rCRF) was applied as a stimulatory inducer of colonic motility and secretion. ICV injection of obestatin (0.1, 0.3, 1.0 nmol/rat) did not modify the colonic transit time, whereas ICV injection of h/rCRF (0.3 nmol/rat) significantly shortened colonic transit time. ICV obestatin in any dose we tested did not affect the fecal pellet output, frequency of watery diarrhea, total fecal weight, fecal dried solid weight, or fecal fluid weight in the first hour post-injection, either. In contrast, ICV injection of h/rCRF effectively stimulated fecal pellet output, as well as increased total fecal weight, fecal dried solid weight and fecal fluid weight during the first hour post-injection, compared to ICV saline controls. In conclusion, using our novel simultaneous measurement method, acutely central administration of obestatin exhibits no influence on colonic motility and secretion in conscious rats.
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Affiliation(s)
- Chih-Yen Chen
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.
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St-Pierre DH, Settanni F, Olivetti I, Gramaglia E, Tomelini M, Granata R, Prodam F, Benso A, Ghigo E, Broglio F. Circulating obestatin levels in normal and Type 2 diabetic subjects. J Endocrinol Invest 2010; 33:211-4. [PMID: 20503481 DOI: 10.1007/bf03345780] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Obestatin has been discovered as a new product of the ghrelin gene. Its physiological actions are still a matter of debate, but it seems that this peptide is likely to be involved in the control of insulin secretion and action as well as of adipocyte function. It has been already shown that obestatin secretion in humans is negatively modulated by food intake. AIM To clarify obestatin secretion in normal subjects and in patients with Type 2 diabetes (T2D) in basal conditions and after a standardized meal. SUBJECTS/METHODS Five normal subjects and 5 T2D patients were studied during infusion of saline (iv for over 5 h from -120 to +180 min). A standardized lunch was served at 0 min. Obestatin, glucose, and insulin levels were assayed at -120, -90, -60, -45, -30, -15, 0, 15, 30, 45, 60, 90, 120, 150, and 180 min. RESULTS From -120 to 0 min, obestatin levels in normal and T2D subjects were similar (area under the curve: 32.3+/-5.6 pg/ml/min vs 31.1+/-1.0 pg/ml/min). After the meal, circulating obestatin levels underwent a clear decrease in normal subjects (0 min: 300.6+/-34.7 pg/ml vs nadir at 60 min: 161.8+/-29.4 pg/ml; p=0.002) but not in diabetic patients (0 min: 267.2+/-16.5 pg/ml vs nadir at 180 min: 226.0+/-10.5 pg/ml). CONCLUSION This study shows that normal and diabetic subjects display similar levels of circulating obestatin in fasting condition. However patients with T2D look refractory to the inhibitory effect of meal on obestatin secretion.
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Affiliation(s)
- D H St-Pierre
- Division of Endocrinology, Diabetology and Metabolism, Department of Internal Medicine, Molinette Hospital, University of Turin, Turin, Italy
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Veldhuis JD, Bowers CY. Integrating GHS into the Ghrelin System. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010:879503. [PMID: 20798846 PMCID: PMC2925380 DOI: 10.1155/2010/879503] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/30/2009] [Indexed: 12/21/2022]
Abstract
Oligopeptide derivatives of metenkephalin were found to stimulate growth-hormone (GH) release directly by pituitary somatotrope cells in vitro in 1977. Members of this class of peptides and nonpeptidyl mimetics are referred to as GH secretagogues (GHSs). A specific guanosine triphosphatate-binding protein-associated heptahelical transmembrane receptor for GHS was cloned in 1996. An endogenous ligand for the GHS receptor, acylghrelin, was identified in 1999. Expression of ghrelin and homonymous receptor occurs in the brain, pituitary gland, stomach, endothelium/vascular smooth muscle, pancreas, placenta, intestine, heart, bone, and other tissues. Principal actions of this peptidergic system include stimulation of GH release via combined hypothalamopituitary mechanisms, orexigenesis (appetitive enhancement), insulinostasis (inhibition of insulin secretion), cardiovascular effects (decreased mean arterial pressure and vasodilation), stimulation of gastric motility and acid secretion, adipogenesis with repression of fat oxidation, and antiapoptosis (antagonism of endothelial, neuronal, and cardiomyocyte death). The array of known and proposed interactions of ghrelin with key metabolic signals makes ghrelin and its receptor prime targets for drug development.
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Affiliation(s)
- Johannes D. Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Cyril Y. Bowers
- Division of Endocrinology, Department of Internal Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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Ghrelin, des-acyl ghrelin, and obestatin: regulatory roles on the gastrointestinal motility. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010. [PMID: 20721292 PMCID: PMC2915652 DOI: 10.1155/2010/305192] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 12/22/2009] [Indexed: 12/16/2022]
Abstract
Ghrelin, des-acyl ghrelin, and obestatin are derived from a common prohormone, preproghrelin by posttranslational processing, originating from endocrine cells in the stomach. To examine the regulatory roles of these peptides, we applied the manometric measurement of gastrointestinal motility in freely moving conscious rat or mouse model. Ghrelin exerts stimulatory effects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum but not on the motility of duodenum in the fasted state of animals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state but not in the fasted state of animals. NPY Y2 and Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptor in the brain may mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain may mediate the action of obestatin. Vagal afferent pathways might be involved in the action of ghrelin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.
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36
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Chen CY, Asakawa A, Fujimiya M, Lee SD, Inui A. Ghrelin gene products and the regulation of food intake and gut motility. Pharmacol Rev 2010; 61:430-81. [PMID: 20038570 DOI: 10.1124/pr.109.001958] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A breakthrough using "reverse pharmacology" identified and characterized acyl ghrelin from the stomach as the endogenous cognate ligand for the growth hormone (GH) secretagogue receptor (GHS-R) 1a. The unique post-translational modification of O-n-octanoylation at serine 3 is the first in peptide discovery history and is essential for GH-releasing ability. Des-acyl ghrelin, lacking O-n-octanoylation at serine 3, is also produced in the stomach and remains the major molecular form secreted into the circulation. The third ghrelin gene product, obestatin, a novel 23-amino acid peptide identified from rat stomach, was found by comparative genomic analysis. Three ghrelin gene products actively participate in modulating appetite, adipogenesis, gut motility, glucose metabolism, cell proliferation, immune, sleep, memory, anxiety, cognition, and stress. Knockdown or knockout of acyl ghrelin and/or GHS-R1a, and overexpression of des-acyl ghrelin show benefits in the therapy of obesity and metabolic syndrome. By contrast, agonism of acyl ghrelin and/or GHS-R1a could combat human anorexia-cachexia, including anorexia nervosa, chronic heart failure, chronic obstructive pulmonary disease, liver cirrhosis, chronic kidney disease, burn, and postsurgery recovery, as well as restore gut dysmotility, such as diabetic or neurogenic gastroparesis, and postoperative ileus. The ghrelin acyl-modifying enzyme, ghrelin O-Acyltransferase (GOAT), which attaches octanoate to serine-3 of ghrelin, has been identified and characterized also from the stomach. To date, ghrelin is the only protein to be octanylated, and inhibition of GOAT may have effects only on the stomach and is unlikely to affect the synthesis of other proteins. GOAT may provide a critical molecular target in developing novel therapeutics for obesity and type 2 diabetes.
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Affiliation(s)
- Chih-Yen Chen
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Japan
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37
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Gao XY, Kuang HY, Liu XM, Ma ZB. Decreased gastric body mucosa obestatin expression in overweight and obese patients. Peptides 2010; 31:291-6. [PMID: 19914322 DOI: 10.1016/j.peptides.2009.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 11/04/2009] [Accepted: 11/04/2009] [Indexed: 11/15/2022]
Abstract
Obestatin is a recently discovered gastrointestinal hormone. It might play a role in the pathophysiology of obesity. We tried to investigate the expression of obestatin in gastric body mucosa in overweight (BMI>or=24 kg/m(2))/obese (BMI>or=28 kg/m(2)) patients. Thirty overweight/obese patients and 20 healthy controls were included in the study. Biopsy specimens of gastric mucosa were obtained from the middle body of the greater curvature. Obestatin expression in gastric mucosa was evaluated by immunohistochemistry. Fasting plasma obestatin levels were measured by radioimmunoassay. The number of obestatin-positive cells in gastric body mucosa was significantly lower in overweight and obese patients than that in healthy subjects. The plasma concentrations of obestatin were also decreased in overweight and obese patients. There was a positive correlation between the numbers of obestatin-positive cells in the gastric body mucosa and circulating obestatin levels. The results indicate that overweight and obese subjects have a reduction in the number of obestatin-positive cells in gastric body mucosa.
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Affiliation(s)
- Xin-Yuan Gao
- Department of Endocrinology, The First Clinical Hospital of Harbin Medical University, Harbin 150001, China
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38
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Xin X, Ren AJ, Zheng X, Qin YW, Zhao XX, Yuan WJ, Guo ZF. Disturbance of circulating ghrelin and obestatin in chronic heart failure patients especially in those with cachexia. Peptides 2009; 30:2281-5. [PMID: 19666068 DOI: 10.1016/j.peptides.2009.07.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/30/2009] [Accepted: 07/30/2009] [Indexed: 11/21/2022]
Abstract
Plasma ghrelin was elevated in chronic heart failure (CHF) patients with cachexia. Obestatin, a sibling of ghrelin, opposes several actions of ghrelin. We, therefore, investigated plasma obestatin and ghrelin levels in patients with CHF. Total plasma ghrelin and obestatin levels were measured in 65 patients with CHF (22 with cardiac cachexia) and 15 controls. Ghrelin levels were significantly higher in patients with cachexia (1237.8+/-47.9 pg/ml) than those without cachexia (P=0.041) and controls (P<0.01). Obestatin levels correlated positively with ghrelin levels, and obestatin levels were significantly increased in patients with cachexia (282.3+/-13.0 pg/ml) than patients without cachexia and controls (both P<0.01). However, the ghrelin to obestatin ratios (4.5+/-0.2) were significantly lower in CHF patients with cachexia than controls (P<0.01). Ghrelin and ratio of ghrelin to obestatin were independent predictors of the development of cardiac cachexia. No association was found between ghrelin, obestatin and New York Heart Association functional class, brain natriuretic peptide. There was disturbance of circulating ghrelin and obestatin in the CHF patients especially those with cachexia, which may have a role in the pathogenesis of cardiac cachexia in CHF.
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Affiliation(s)
- Xing Xin
- Department of Cardiovascular Diseases, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433, China
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Perboni S, Inui A. Appetite and gastrointestinal motility: role of ghrelin-family peptides. Clin Nutr 2009; 29:227-34. [PMID: 19945199 DOI: 10.1016/j.clnu.2008.10.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 09/28/2008] [Accepted: 10/30/2008] [Indexed: 12/26/2022]
Abstract
Eating disorders, obesity and cachexia endanger the lives of millions of people worldwide. Fortunately, in last decade, there has been a rapid and substantial progress toward uncovering the molecular and neural mechanisms by which energy imbalance develops. In 1999, ghrelin was identified as the first orexigenic gut-derived peptide. It stimulates appetite and controls the gastric motility and the acid secretion through the activation of the growth hormone secretagogue-receptor. After the discovery of ghrelin, other forms of ghrelin-related proteins were isolated from the rat stomach. The unmodified des-n-octanoyl form (des-acyl ghrelin) and the recent obestatin act through distinct receptors and contrarily to acyl ghrelin, show an anorexigenic activity. The finding that these three peptide hormones derive from the same precursor exert opposing physiological actions, highlights the importance of post-translational regulatory mechanisms. Further investigations are required to highlight the complexity of ghrelin physiology in order to better understand the mechanisms regulating the energy balance and provide a successful treatment of eating disorders, obesity and cachexia.
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Affiliation(s)
- Simona Perboni
- Unità Operativa Day-Hospital Area Medica, Ospedale di Manerbio, Azienda Ospedaliera di Desenzano del Garda, Brescia I-25025, Italy.
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40
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Nagaraj S, Peddha MS, Manjappara UV. Fragment analogs as better mimics of obestatin. ACTA ACUST UNITED AC 2009; 158:143-8. [DOI: 10.1016/j.regpep.2009.08.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 08/07/2009] [Accepted: 08/16/2009] [Indexed: 10/20/2022]
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41
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Ghrelin and obestatin levels in type 2 diabetic patients with and without delayed gastric emptying. Dig Dis Sci 2009; 54:2161-6. [PMID: 19082715 DOI: 10.1007/s10620-008-0622-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Accepted: 11/03/2008] [Indexed: 12/12/2022]
Abstract
Alterations in the neurohumoral regulation of the upper intestine may change rhythmicity and pattern of ghrelin and obestatin, the latter presumably antagonizing ghrelin effects. Five nongastroparetic diabetic patients and five with gastroparesis were investigated. Over 390 min including breakfast and lunch, ghrelin was significantly lower in patients with gastroparesis compared with in those without (P = 0.015). Ghrelin subsequent to lunch decreased significantly (P = 0.011) in patients without gastroparesis, but not in gastroparetic patients (P = 0.669). Obestatin was similar in both groups and unchanged. No significant differences in ghrelin-to-obestatin ratio were observed (P = 0.530). Loss of rhythmicity in the ghrelin levels of gastroparetic diabetics highlights the importance of integrity of the neurohumoral-intestinal axis. Stable diurnal obestatin levels do not support the concept of interaction between ghrelin and obestatin in terms of regulation of food intake and gastric emptying.
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42
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Aygen B, Dogukan A, Dursun FE, Aydin S, Kilic N, Sahpaz F, Celiker H. Ghrelin and obestatin levels in end-stage renal disease. J Int Med Res 2009; 37:757-65. [PMID: 19589259 DOI: 10.1177/147323000903700319] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Malnutrition is fairly common in end-stage renal disease (ESRD) patients, persistent lack of appetite being a major symptom. Ghrelin and obestatin are two hormones that are involved in appetite and energy homeostasis. The present study examined ghrelin and obestatin levels in 24 ESRD patients undergoing haemodialysis and 24 age-matched healthy controls. Serum and saliva ghrelin and obestatin levels in the ESRD patients were significantly higher compared with controls, while saliva ghrelin and obestatin levels in all study participants were significantly higher than serum levels. Saliva ghrelin correlated with serum ghrelin and saliva obestatin correlated with serum obestatin in all study participants, although there was no correlation between ghrelin and obestatin levels. In conclusion, the results suggest that the kidneys may have a role in the metabolism and/or clearance of obestatin, as they do for ghrelin. Further studies are needed to determine if elevated levels of these hormones in ESRD patients contribute to the malnutrition that is common in these patients.
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Affiliation(s)
- B Aygen
- Department of Nephrology, Medical Faculty, Firat University, Elazig, Turkey.
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43
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The preproghrelin gene is required for the normal integration of thermoregulation and sleep in mice. Proc Natl Acad Sci U S A 2009; 106:14069-74. [PMID: 19666521 DOI: 10.1073/pnas.0903090106] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Peptidergic mechanisms controlling feeding, metabolism, thermoregulation, and sleep overlap in the hypothalamus. Low ambient temperatures and food restriction induce hypothermic (torpor) bouts and characteristic metabolic and sleep changes in mice. We report that mice lacking the preproghrelin gene, but not those lacking the ghrelin receptor, have impaired abilities to manifest and integrate normal sleep and thermoregulatory responses to metabolic challenges. In response to fasting at 17 degrees C (a subthermoneutral ambient temperature), preproghrelin knockout mice enter hypothermic bouts associated with reduced sleep, culminating in a marked drop in body temperature to near-ambient levels. Prior treatment with obestatin, another preproghrelin gene product, attenuates the hypothermic response of preproghrelin knockout mice. Results suggest that obestatin is a component in the coordinated regulation of metabolism and sleep during torpor.
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Volante M, Rosas R, Ceppi P, Rapa I, Cassoni P, Wiedenmann B, Settanni F, Granata R, Papotti M. Obestatin in human neuroendocrine tissues and tumours: expression and effect on tumour growth. J Pathol 2009; 218:458-66. [DOI: 10.1002/path.2551] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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45
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Annemie VD, Debby VD, Valentijn V, Bart DS, Walter L, Liliane S, Peter Paul DD. Central administration of obestatin fails to show inhibitory effects on food and water intake in mice. ACTA ACUST UNITED AC 2009; 156:77-82. [DOI: 10.1016/j.regpep.2009.04.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 04/06/2009] [Accepted: 04/29/2009] [Indexed: 11/29/2022]
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46
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Lorenzi T, Meli R, Marzioni D, Morroni M, Baragli A, Castellucci M, Gualillo O, Muccioli G. Ghrelin: a metabolic signal affecting the reproductive system. Cytokine Growth Factor Rev 2009; 20:137-52. [DOI: 10.1016/j.cytogfr.2009.02.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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47
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Dong XY, He JM, Tang SQ, Li HY, Jiang QY, Zou XT. Is GPR39 the natural receptor of obestatin? Peptides 2009; 30:431-8. [PMID: 18977259 DOI: 10.1016/j.peptides.2008.09.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2008] [Revised: 08/25/2008] [Accepted: 09/25/2008] [Indexed: 12/15/2022]
Abstract
GPR39, an orphan receptor belonging to the family of G protein-coupled receptors, was originally reported to be the receptor of obestatin. However recently, numerous reports have questioned this conclusion. In mammals, GPR39 was reported to be involved in the regulation of gastrointestinal and the metabolic functions. In this article, a latest and brief review on the receptor family, structure, distribution and physiological functions of GPR39 has been reported.
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Affiliation(s)
- Xiao-Ying Dong
- College of Yingdong Bioengineering, Shaoguan University, Daxue Avenue, Zhenjiang District, Shaoguan 512005, China
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48
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Ren AJ, Guo ZF, Wang YK, Lin L, Zheng X, Yuan WJ. Obestatin, obesity and diabetes. Peptides 2009; 30:439-44. [PMID: 18992781 DOI: 10.1016/j.peptides.2008.10.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/04/2008] [Accepted: 10/06/2008] [Indexed: 01/07/2023]
Abstract
The high prevalence of obesity and diabetes will lead to higher rates of morbidity and mortality. It is well known that ghrelin plays a potential role in obesity and diabetes. Obestatin, a novel 23 amino acid amidated peptide encoded by the same gene that encodes ghrelin, was initially reported to have opposite actions to ghrelin in the regulation of food intake, emptying of the stomach and body weight. Recent work suggests that obestatin also regulate beta-cell survival and insulin secretion. The ghrelin-obestatin system is, therefore, a promising target for the developing of new drugs for the treatment of obesity and diabetes. This review summarizes the interrelationship between obestatin, obesity and diabetes.
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Affiliation(s)
- An-Jing Ren
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
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49
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Gao XY, Kuang HY, Liu XM, Duan P, Yang Y, Ma ZB. Circulating ghrelin/obestatin ratio in subjects with Helicobacter pylori infection. Nutrition 2009; 25:506-11. [PMID: 19131215 DOI: 10.1016/j.nut.2008.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 11/04/2008] [Accepted: 11/04/2008] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Ghrelin is a peptide hormone involved in human energy homeostasis. Obestatin is a recently discovered active peptide derived from preproghrelin. It seemed that obestatin was a physiologic opponent of ghrelin. Helicobacter pylori infection may be associated with appetite and nutrition. We compared the plasma ghrelin/obestatin ratio in H. pylori-positive and -negative groups. METHODS People undergoing an annual health checkup were included. Helicobacter pylori status was based on serologic and carbon-13 urea breath findings. Fifty adults with H. pylori infection and 50 adults matched by age and body mass index without H. pylori infection were enrolled in this study. Plasma ghrelin and obestatin levels were measured by radioimmunoassay. RESULTS Ghrelin concentrations and ghrelin/obestatin ratios were lower in the H. pylori-positive group than in the H. pylori-negative group. There was no significant difference in circulating obestatin between those with and without H. pylori infection. In all subjects, the ghrelin/obestatin ratio was negatively correlated with body mass index, the homeostasis model of assessment for insulin resistance, and serum levels of triacylglycerol. There was a positive correlation between circulating obestatin and ghrelin levels. CONCLUSION Helicobacter pylori infection was associated with a reduction in the circulating ghrelin/obestatin ratio in Chinese adults.
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Affiliation(s)
- Xin-Yuan Gao
- Department of Endocrinology, The First Clinical Hospital of Harbin Medical University, Harbin, China
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Egido EM, Hernández R, Marco J, Silvestre RA. Effect of obestatin on insulin, glucagon and somatostatin secretion in the perfused rat pancreas. ACTA ACUST UNITED AC 2009; 152:61-6. [DOI: 10.1016/j.regpep.2008.08.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 07/08/2008] [Accepted: 08/07/2008] [Indexed: 11/17/2022]
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