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Posovszky C, Wabitsch M. Regulation of appetite, satiation, and body weight by enteroendocrine cells. Part 1: characteristics of enteroendocrine cells and their capability of weight regulation. Horm Res Paediatr 2015; 83:1-10. [PMID: 25471008 DOI: 10.1159/000368898] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 09/23/2014] [Indexed: 11/19/2022] Open
Abstract
The gastrointestinal tract is the gateway for food in our body. Food ingestion and the ensuing digestive processes depend on the composition and amount of ingested nutrients. This complex process of nutrient digestion and absorption is effectively regulated by the enteroendocrine system. Enteroendocrine cells (EECs) reside scattered throughout the intestinal epithelium. They express nutrient receptors that face the lumen and secrete peptide hormones in response to food. Besides regulating digestion, gastrointestinal endocrine cells are involved in the regulation of appetite and satiety. The first part of this review describes the anatomical and biological characteristics of EECs and discusses the capability of their hormones to influence appetite, satiety, and body weight. In the second part, we then discuss the therapeutic potential of EECs in the treatment of obesity.
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Affiliation(s)
- Carsten Posovszky
- University Outpatient Clinic for Pediatric Gastroenterology, and Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany
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Miki K, Maekura R, Nakazato M, Matsumoto N, Kitada S, Miki M, Yoshimura K, Mori M, Kangawa K. Randomized, dose-finding trial of ghrelin treatment for chronic respiratory failure. CLINICAL RESPIRATORY JOURNAL 2015; 11:496-505. [PMID: 26260705 DOI: 10.1111/crj.12364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 07/07/2015] [Accepted: 08/03/2015] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Ghrelin, a growth hormone-releasing peptide, has shown efficacy in chronic obstructive pulmonary disease (COPD) patients in previous trials. This study was designed to evaluate the effective dose of ghrelin in chronic respiratory failure patients. METHODS In this randomized, double-blind, dose-finding, single-center study, 18 patients, including 16 with COPD, were randomly assigned to receive pulmonary rehabilitation (PR) with intravenous ghrelin at 1 μg/kg or 2 μg/kg, twice daily for 3 weeks. The primary outcome was the change in peak oxygen uptake ( V˙o2). Secondary outcomes included changes in plasma vascular endothelial growth factor (VEGF)-A levels, and exertional cardio-respiratory functions with blood gas analysis. RESULTS With incremental exercise, there was no significant differences in the mean difference (high-dose ghrelin minus low-dose ghrelin) of peak V˙o2 (1.0 mL/kg/min, 95% CI: -0.6 to 2.6 mL/kg/min, between-group, P = 0.193). However, there were significant differences in the mean difference of (i) O2 -pulse (0.6 mL/beats, 95% CI: 0.0 to 1.1 mL/beats, between-group, P = 0.035) at iso-time; and ii) PaO2 (4.2 mmHg, 95% CI: 0.2 to 8.2 mmHg, between-group, P = 0.041) and PaCO2 (-3.1 mmHg, 95% CI: -6.0 to -0.3 mmHg, between-group, P = 0.034) at peak exercise. The mean difference in the plasma VEGF-A level was significantly inhibited by high dose-ghrelin with PR (-125.4 pg/mL, 95% CI: -235.2 to -15.5 pg/mL, between-group, P = 0.028). CONCLUSION Although the primary outcome of the study was not met, high-dose ghrelin with PR improved exertional cardiac function and blood gas values, and inhibited circulating VEGF-A levels.
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Affiliation(s)
- Keisuke Miki
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Ryoji Maekura
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Masamitsu Nakazato
- Neurology, Respirology, Endocrinology and Metabolism, Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Nobuhiro Matsumoto
- Neurology, Respirology, Endocrinology and Metabolism, Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Seigo Kitada
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Mari Miki
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Kenji Yoshimura
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Masahide Mori
- Department of Respiratory Medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
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Haass-Koffler CL, Aoun EG, Swift RM, de la Monte SM, Kenna GA, Leggio L. Leptin levels are reduced by intravenous ghrelin administration and correlated with cue-induced alcohol craving. Transl Psychiatry 2015; 5:e646. [PMID: 26418274 PMCID: PMC5545639 DOI: 10.1038/tp.2015.140] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/08/2015] [Accepted: 06/01/2015] [Indexed: 01/24/2023] Open
Abstract
Increasing evidence supports the role of appetite-regulating pathways, including ghrelin and leptin, in alcoholism. This study tested the hypothesis that intravenous exogenous ghrelin administration acutely decreases endogenous serum leptin levels, and that changes in leptin levels negatively correlate with alcohol craving. This was a double-blind, placebo-controlled human laboratory study. Non-treatment-seeking, alcohol-dependent, heavy drinkers (n=45) were randomized to receive intravenous ghrelin or placebo, followed by a cue-reactivity procedure, during which participants were exposed to neutral (juice) and alcohol trial cues. There was a main effect for intravenous ghrelin administration, compared with placebo, in reducing serum leptin levels (P<0.01). Post hoc analysis showed significant differences in serum leptin levels at the alcohol trial (P<0.05) that persisted at the end of the experiment (P<0.05). By contrast, there were no significant differences in serum leptin levels at the juice trial (P=not significant (NS)). The change of serum leptin level at the alcohol trial correlated with the increase in alcohol urge (P<0.05), whereas urge to drink juice was not correlated with the leptin change at the juice trial (P=NS). These findings provide preliminary evidence of ghrelin-leptin cross-talk in alcoholic individuals and suggest that their relationship may have a role in alcohol craving.
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Affiliation(s)
- C L Haass-Koffler
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA
| | - E G Aoun
- Department of Psychiatry and Human Behavior, Brown University, Providence, RI, USA
| | - R M Swift
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI, USA,Veterans Affairs Medical Center, Providence, RI, USA
| | - S M de la Monte
- Departments of Pathology, Neurology, and Neurosurgery, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - G A Kenna
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI, USA
| | - L Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA,Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, 10 Center Drive (10CRC/15330) MSC 1108, Room 1-5429, Bethesda, MD 20892-1108, USA. E-mail:
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55
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Kunath N, van Groen T, Allison DB, Kumar A, Dozier-Sharpe M, Kadish I. Ghrelin agonist does not foster insulin resistance but improves cognition in an Alzheimer's disease mouse model. Sci Rep 2015; 5:11452. [PMID: 26090621 PMCID: PMC4473679 DOI: 10.1038/srep11452] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 05/15/2015] [Indexed: 12/24/2022] Open
Abstract
The orexigenic hormone ghrelin, a potential antagonist of the insulin system, ensures sufficient serum glucose in times of fasting. In the race for new therapeutics for diabetes, one focus of study has been antagonizing the ghrelin system in order to improve glucose tolerance. We provide evidence for a differential role of a ghrelin agonist on glucose homeostasis in an Alzheimer’s disease mouse model fed a high–glycemic index diet as a constant challenge for glucose homeostasis. The ghrelin agonist impaired glucose tolerance immediately after administration but not in the long term. At the same time, the ghrelin agonist improved spatial learning in the mice, raised their activity levels, and reduced their body weight and fat mass. Immunoassay results showed a beneficial impact of long-term treatment on insulin signaling pathways in hippocampal tissue. The present results suggest that ghrelin might improve cognition in Alzheimer’s disease via a central nervous system mechanism involving insulin signaling.
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Affiliation(s)
- Nicolas Kunath
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL, USA.,Department of Clinical Research, Max-Planck-Institute of Psychiatry, Munich, Germany
| | - Thomas van Groen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL, USA
| | - David B Allison
- Office of Energetics; Nutrition Obesity Research Center; Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ashish Kumar
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL, USA
| | - Monique Dozier-Sharpe
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL, USA
| | - Inga Kadish
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL, USA
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Abstract
The anorexia of aging is common, leading to adverse health consequences. As populations age, the impacts from anorexia in the older population are set to increase. Only greater awareness will allow for prevention or early intervention. This article discusses the physiologic anorexia of aging, highlights contributing factors, and proposes management strategies, including screening, especially in primary care. Many neuroendocrine factors have been implicated in the pathophysiology; it is clear that further human research is necessary if there is to be a pharmacologic breakthrough. There are currently no approved pharmacologic treatment strategies to prevent or treat the anorexia of aging.
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Affiliation(s)
- Renuka Visvanathan
- Aged & Extended Care Services, Level 8B, The Queen Elizabeth Hospital, Woodville Road, Woodville South, Adelaide, SA 5011, Australia.
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Abstract
The gastrointestinal (GI) tract comprises a large endocrine organ that regulates not only nutrient sensing and metabolising but also satiety and energy homeostasis. More than 20 hormones secreted from the stomach, intestine, and pancreas as well as signaling mediators of the gut microbiome are involved in this process. A better understanding of how related pathways affect body weight and food intake will help us to find new strategies and drugs to treat obesity. For example, weight loss secondary to lifestyle intervention is often accompanied by unfavorable changes in multiple GI hormones, which may cause difficulties in maintaining a lower body weight status. Conversely, bariatric surgery favorably changes the hormone profile to support improved satiety and metabolic function. This partially explains stronger sustained body weight reduction resulting in better long-term results of improved metabolic functions. This review focuses on GI hormones and signaling mediators of the microbiome involved in satiety regulation and energy homeostasis and summarizes their changes following weight loss. Furthermore, the potential role of GI hormones as anti-obesity drugs is discussed.
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Affiliation(s)
- Thomas Reinehr
- Vestische Hospital for Children and Adolescents Datteln, Institute for Pediatric Endocrinology, Diabetes and Nutrition Medicine, University of Witten/Herdecke, Datteln, Germany,
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Cornell S. Continual evolution of type 2 diabetes: an update on pathophysiology and emerging treatment options. Ther Clin Risk Manag 2015; 11:621-32. [PMID: 25931824 PMCID: PMC4404882 DOI: 10.2147/tcrm.s67387] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Diabetes is a complex and progressive disease that has a major societal and economic impact. The most common form of diabetes, type 2 diabetes mellitus (T2DM), is a multifactorial disease, the pathophysiology of which involves not only the pancreas but also the liver, skeletal muscle, adipose tissue, gastrointestinal tract, brain, and kidney. Novel therapies with mechanisms of action that are different from most existing drugs are emerging. One such class consists of compounds that inhibit renal sodium-glucose cotransporter 2, which is responsible for the bulk of glucose reabsorption by the kidneys. This new class of compounds improves glycemic control independently of insulin and promotes weight reduction, providing an additional tool to treat patients with T2DM. This review discusses the underlying pathophysiology of T2DM, clinical guidelines, and available and emerging treatment options, with particular emphasis on sodium-glucose cotransporter 2 inhibitors.
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Affiliation(s)
- Susan Cornell
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, USA
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Pena-Bello L, Pertega-Diaz S, Outeiriño-Blanco E, Garcia-Buela J, Tovar S, Sangiao-Alvarellos S, Dieguez C, Cordido F. Effect of oral glucose administration on rebound growth hormone release in normal and obese women: the role of adiposity, insulin sensitivity and ghrelin. PLoS One 2015; 10:e0121087. [PMID: 25782001 PMCID: PMC4363632 DOI: 10.1371/journal.pone.0121087] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/30/2015] [Indexed: 12/17/2022] Open
Abstract
Context Metabolic substrates and nutritional status play a major role in growth hormone (GH) secretion. Uncovering the mechanisms involved in GH secretion following oral glucose (OG) administration in normal and obese patients is a pending issue. Objective The aim of this study was to investigate GH after OG in relation with adiposity, insulin secretion and action, and ghrelin secretion in obese and healthy women, to further elucidate the mechanism of GH secretion after OG and the altered GH secretion in obesity. Participants and Methods We included 64 healthy and obese women. After an overnight fast, 75 g of OG were administered; GH, glucose, insulin and ghrelin were obtained during 300 minutes. Insulin secretion and action indices and the area under the curve (AUC) were calculated for GH, glucose, insulin and ghrelin. Univariate and multivariate linear regression analyses were employed. Results The AUC of GH (μg/L•min) was lower in obese (249.8±41.8) than in healthy women (490.4±74.6), P=0.001. The AUC of total ghrelin (pg/mL•min) was lower in obese (240995.5±11094.2) than in healthy women (340797.5±37757.5), P=0.042. There were significant correlations between GH secretion and the different adiposity, insulin secretion and action, and ghrelin secretion indices. After multivariate analysis only ghrelin AUC remained a significant predictor for fasting and peak GH.
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Affiliation(s)
- Lara Pena-Bello
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Sonia Pertega-Diaz
- Clinical Epidemiology and Biostatistics Unit, University Hospital A Coruña, A Coruña, Spain
| | | | - Jesus Garcia-Buela
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Sulay Tovar
- Department of Physiology (CIMUS), School of Medicine-Instituto de Investigaciones Sanitarias (IDIS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain, and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Susana Sangiao-Alvarellos
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Carlos Dieguez
- Department of Physiology (CIMUS), School of Medicine-Instituto de Investigaciones Sanitarias (IDIS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain, and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Fernando Cordido
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
- Department of Endocrinology, University Hospital A Coruña, A Coruña, Spain
- * E-mail:
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Camilleri M, Acosta A. Emerging treatments in Neurogastroenterology: relamorelin: a novel gastrocolokinetic synthetic ghrelin agonist. Neurogastroenterol Motil 2015; 27:324-32. [PMID: 25545036 PMCID: PMC4424792 DOI: 10.1111/nmo.12490] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/20/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND Synthetic ghrelin agonists, predominantly small molecules, are being developed as prokinetic agents that may prove useful in the treatment of gastrointestinal motility disorders. Relamorelin (RM-131) is a pentapeptide synthetic ghrelin analog that activates the growth hormone secretagogue (GHS)-1a (also called the ghrelin) receptor with approximately sixfold greater potency than natural ghrelin. The ability of relamorelin to stimulate growth hormone (GH) release is comparable to that of native ghrelin. Relamorelin has enhanced efficacy and plasma stability compared to native ghrelin. PURPOSE In this review, we discuss the pharmacokinetics, pharmacodynamics and potential indications for relamorelin. Relamorelin is administered subcutaneously, dosed daily or twice daily. Relamorelin is being studied for the treatment of patients with gastrointestinal motility disorders. Phase IIA pharmacodynamic studies have demonstrated acceleration of gastric emptying in patients with type 1 diabetes mellitus (T1DM) and type 2 DM (T2DM) and upper gastrointestinal symptoms. In a phase IIA study in patients with diabetic gastroparesis, relamorelin accelerated gastric emptying and significantly improved vomiting frequency compared to placebo and improved other symptoms of gastroparesis in a prespecified subgroup of patients with vomiting at baseline. In patients with chronic idiopathic constipation with defined transit profile at baseline, relamorelin relieved constipation and accelerated colonic transit compared to placebo. These characteristics suggest that this new ghrelin analog shows great promise to relieve patients with upper or lower gastrointestinal motility disorders.
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Affiliation(s)
- M. Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.); Mayo Clinic; Rochester MN USA
| | - A. Acosta
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.); Mayo Clinic; Rochester MN USA
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Wittekind DA, Kluge M. Ghrelin in psychiatric disorders - A review. Psychoneuroendocrinology 2015; 52:176-94. [PMID: 25459900 DOI: 10.1016/j.psyneuen.2014.11.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022]
Abstract
Ghrelin is a 28-amino-acid peptide hormone, first described in 1999 and broadly expressed in the organism. As the only known orexigenic hormone secreted in the periphery, it increases hunger and appetite, promoting food intake. Ghrelin has also been shown to be involved in various physiological processes being regulated in the central nervous system such as sleep, mood, memory and reward. Accordingly, it has been implicated in a series of psychiatric disorders, making it subject of increasing investigation, with knowledge rapidly accumulating. This review aims at providing a concise yet comprehensive overview of the role of ghrelin in psychiatric disorders. Ghrelin was consistently shown to exert neuroprotective and memory-enhancing effects and alleviated psychopathology in animal models of dementia. Few human studies show a disruption of the ghrelin system in dementia. It was also shown to play a crucial role in the pathophysiology of addictive disorders, promoting drug reward, enhancing drug seeking behavior and increasing craving in both animals and humans. Ghrelin's exact role in depression and anxiety is still being debated, as it was shown to both promote and alleviate depressive and anxiety-behavior in animal studies, with an overweight of evidence suggesting antidepressant effects. Not surprisingly, the ghrelin system is also implicated in eating disorders, however its exact role remains to be elucidated. Its widespread involvement has made the ghrelin system a promising target for future therapies, with encouraging findings in recent literature.
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Affiliation(s)
| | - Michael Kluge
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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Kraemer RR, Castracane VD. Endocrine alterations from concentric vs. eccentric muscle actions: a brief review. Metabolism 2015; 64:190-201. [PMID: 25467839 DOI: 10.1016/j.metabol.2014.10.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/22/2014] [Accepted: 10/23/2014] [Indexed: 12/31/2022]
Abstract
Resistance exercise has a positive effect on many tissues, including heart, bone, skeletal muscle, and nervous tissue. Eccentric muscle actions offer a unique and a potentially beneficial form of exercise for maintaining and improving health. During resistance exercise, the effects of gravity, and mechanical properties of the sarcomere and connective tissue in skeletal muscle allow a greater muscle load during an eccentric (lengthening) muscle contraction than a concentric (shortening) muscle contraction. Consequently, older patients, patients with muscle or limb movement limitations or injuries, as well as cancer patients may be able to benefit from isolated eccentric muscle actions. There are specific physiological responses to eccentric muscle contractions. This review will describe the effects of different eccentric muscle contraction protocols on endocrine responses that could have positive effects on different tissues and recommend direction for future research.
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Affiliation(s)
- Robert R Kraemer
- Deparment of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, LA, 70402.
| | - V Daniel Castracane
- Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center, 701 W. 5th St. Odessa, TX, 79763
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Genetic determination of the cellular basis of the ghrelin-dependent bone remodeling. Mol Metab 2015; 4:175-85. [PMID: 25737953 PMCID: PMC4338319 DOI: 10.1016/j.molmet.2015.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 12/31/2014] [Accepted: 01/08/2015] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Bone mass is maintained through a balance of bone formation and resorption. This homeostatic balance is regulated by various systems involving humoral and local factors. The discovery that the anorexigenic hormone leptin regulates bone mass via neuronal pathways revealed that neurons and neuropeptides are intimately involved in bone homeostasis. Ghrelin is a stomach-derived orexigenic hormone that counteracts leptin's action. However, the physiological role of ghrelin in bone homeostasis remains unknown. In this study, through the global knockout of ghrelin receptor (Ghsr) followed by tissue-specific re-expression, we addressed the molecular basis of the action of ghrelin in bone remodeling in vivo. METHODS We performed molecular, genetic and cell biological analyses of Ghsr-null mice and Ghsr-null mice with tissue specific Ghsr restoration. Furthermore, we evaluated the molecular mechanism of ghrelin by molecular and cell-based assays. RESULTS Ghsr-null mice showed a low bone mass phenotype with poor bone formation. Restoring the expression of Ghsr specifically in osteoblasts, and not in osteoclasts or the central nervous system, ameliorated bone abnormalities in Ghsr-null mice. Cell-based assays revealed ghrelin induced the phosphorylation of CREB and the expression of Runx2, which in turn accelerated osteoblast differentiation. CONCLUSIONS Our data show that ghrelin regulates bone remodeling through Ghsr in osteoblasts by modulating the CREB and Runx2 pathways.
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Kim C, Randolph JF, Golden SH, Labrie F, Kong S, Nan B, Barrett-Connor E. Weight loss increases follicle stimulating hormone in overweight postmenopausal women [corrected]. Obesity (Silver Spring) 2015; 23:228-33. [PMID: 25294746 PMCID: PMC4276440 DOI: 10.1002/oby.20917] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/11/2014] [Indexed: 12/25/2022]
Abstract
OBJECTIVES To examine the impact of a weight loss intervention upon follicle stimulating hormone (FSH) levels in postmenopause. METHODS Participants were postmenopausal, overweight, glucose-intolerant women not using exogenous estrogen (n = 382) in the Diabetes Prevention Program. Women were randomized to intensive lifestyle change (ILS) with the goals of weight reduction of at least 7% of initial weight and 150 min per week of moderate-intensity exercise, metformin 850 mg twice a day, or placebo administered twice a day. RESULTS Randomization to ILS led to small increases in FSH between baseline and 1-year follow-up vs. placebo (2.3 IU/l vs. -0.81 IU/l, P < 0.01). Increases in FSH were correlated with decreases in weight (r = -0.165, P < 0.01) and estradiol (E2) (r = -0.464, P < 0.0001) after adjustment for age, race/ethnicity, and randomization arm. Changes in FSH were still significantly associated with changes in weight even after adjustment for E2 levels. Metformin users had reductions in weight but non-significant changes in FSH and E2 levels vs. placebo. CONCLUSIONS Weight loss leads to small increases in FSH among overweight, postmenopausal women, potentially through pathways mediated by endogenous estrogen as well as other pathways.
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Affiliation(s)
- Catherine Kim
- Departments of Medicine and Obstetrics & Gynecology, University of Michigan, Ann Arbor, Michigan, USA
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Kim CY, Paxton BE, Weiss CR, Arepally A. Bariatric embolization for the treatment of obesity. GASTROINTESTINAL INTERVENTION 2014. [DOI: 10.1016/j.gii.2014.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Leggio L, Zywiak WH, Fricchione SR, Edwards SM, de la Monte SM, Swift RM, Kenna GA. Intravenous ghrelin administration increases alcohol craving in alcohol-dependent heavy drinkers: a preliminary investigation. Biol Psychiatry 2014; 76:734-41. [PMID: 24775991 PMCID: PMC4176606 DOI: 10.1016/j.biopsych.2014.03.019] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND There is a need to identify novel pharmacologic targets to treat alcoholism. Animal and human studies suggest a role for ghrelin in the neurobiology of alcohol dependence and craving. Here, we were the first to test the hypothesis that intravenous administration of exogenous ghrelin acutely increases alcohol craving. METHODS This was a double-blind, placebo-controlled human laboratory proof-of-concept study. Nontreatment-seeking, alcohol-dependent, heavy-drinking individuals were randomized to receive intravenous ghrelin 1 mcg/kg, 3 mcg/kg or 0 mcg/kg (placebo), followed by a cue-reactivity procedure, during which participants were exposed to neutral (juice) and alcohol cues. The primary outcome variable was the increase in alcohol craving (also called urge) for alcohol, assessed by the Alcohol Visual Analogue Scale. RESULTS Out of 103 screenings, 45 individuals received the study drug. Repeated measures of analysis of covariance revealed a group effect across ghrelin doses in increasing alcohol craving (p < .05). A dose-specific examination revealed a significant effect of ghrelin 3 mcg/kg versus placebo in increasing alcohol craving (p < .05) with a large effect size (d = .94). By contrast, no significant ghrelin effect was found in increasing either urge to drink juice or food craving (p = ns). No significant differences in side effects were found (p = ns). CONCLUSIONS Intravenous administration of exogenous ghrelin increased alcohol craving in alcohol-dependent heavy-drinking individuals. Although the small sample requires confirmatory studies, these findings provide preliminary evidence that ghrelin may play a role in the neurobiology of alcohol craving, thus demonstrating a novel pharmacologic target for treatment.
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Affiliation(s)
- Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland; Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland; Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence.
| | - William H. Zywiak
- Decision Sciences Institute, P.I.R.E., Pawtucket, RI,Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI
| | - Samuel R. Fricchione
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI
| | - Steven M. Edwards
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE
| | - Suzanne M. de la Monte
- Departments of Pathology, Neurology, and Neurosurgery, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI
| | - Robert M. Swift
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI,Veterans Affairs Medical Center, Providence, RI
| | - George A. Kenna
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI
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67
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Callaghan B, Furness JB. Novel and Conventional Receptors for Ghrelin, Desacyl-Ghrelin, and Pharmacologically Related Compounds. Pharmacol Rev 2014; 66:984-1001. [DOI: 10.1124/pr.113.008433] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Abstract
PURPOSE OF REVIEW Significant progress has been made in the field of defining and describing the pathophysiology of wasting conditions such as cachexia. The number of new promising drugs, nutritional therapy alternatives, and exercise/rehabilitation programs is increasing. The purpose of this review is to give an overview of recent clinical findings from intervention studies investigating multimodal anabolic therapies utilizing drug, nutritional, and/or exercise interventions in order to counteract wasting. RECENT FINDINGS Anabolic agents such as ghrelin and selective androgen receptor modulators are under late-phase clinical testing and hold promise as new therapies, and their ability to mitigate weight loss and improve muscle mass and physical function is evaluated. In the past 2 years, eight new studies investigating interventions with anabolic potential in wasting have been published, among which three of these studies were multimodal. SUMMARY Targeted anabolic therapies aiming to prevent or reverse wasting might involve a combination of anabolic pharmacologic drugs, nutrition, and physical exercise working concurrently to enhance muscle protein synthesis and reduce breakdown. Some anabolic pharmacological interventions demonstrate the potential to improve muscle mass, but the multimodal interventions seem in greater extent to also demonstrate improvement in physical function.
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Affiliation(s)
- Trude Rakel Balstad
- aEuropean Palliative Care Research Centre (PRC), Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU) bCancer Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
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69
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Takiguchi S, Takata A, Murakami K, Miyazaki Y, Yanagimoto Y, Kurokawa Y, Takahashi T, Mori M, Doki Y. Clinical application of ghrelin administration for gastric cancer patients undergoing gastrectomy. Gastric Cancer 2014; 17:200-5. [PMID: 24253567 DOI: 10.1007/s10120-013-0300-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 08/30/2013] [Indexed: 02/07/2023]
Abstract
Loss of body weight is a common (and the most serious) sequela after gastrectomy. It impairs quality of life, increases various diseases including infection, and may affect long-term survival. Ghrelin, an intrinsic ligand of the growth hormone secretagogue receptor, was discovered in the stomach in 1999. In addition to growth hormone secretion, ghrelin has pleiotropic functions including appetite stimulation, increasing bowel movement and absorption, and anti-inflammatory reactions. In consequence, ghrelin comprehensively leads positive energy balance and weight gain. The fundic gland of the stomach produces the majority of ghrelin, and plasma ghrelin declines to 10-30 % of the preoperative level after total gastrectomy and 50-70 % after distal gastrectomy. Although plasma ghrelin is never restored after total gastrectomy, it gradually recovers to the preoperative level within a few years after distal gastrectomy. Chronic gastritis due to Helicobacter pylori infection and vagotomy are additional factors that perturb the ghrelin secretion of gastric cancer patients after gastrectomy. A randomized clinical trial that revealed that recombinant ghrelin administration successfully increased both food intake and appetite, and ameliorated weight loss after total gastrectomy. Ghrelin administration could thus be a promising strategy to transiently improve the nutritional status of patients who who have undergone gastrectomy, but its effect in the long term remains unclear. Further studies are warranted to elucidate the mechanism of ghrelin and to create and evaluate the analogs that could be administered orally or subcutaneously.
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Affiliation(s)
- Shuji Takiguchi
- Division of Gastroenterological Surgery, Department of Surgery, Graduate School of Medicine, Osaka University, 2-2 E2 Yamadaoka, Suita, Osaka, 565-0871, Japan,
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70
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Affiliation(s)
- Patricia L. Brubaker
- Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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71
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Gahete MD, Rincón-Fernández D, Villa-Osaba A, Hormaechea-Agulla D, Ibáñez-Costa A, Martínez-Fuentes AJ, Gracia-Navarro F, Castaño JP, Luque RM. Ghrelin gene products, receptors, and GOAT enzyme: biological and pathophysiological insight. J Endocrinol 2014; 220:R1-24. [PMID: 24194510 DOI: 10.1530/joe-13-0391] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin is a 28-amino acid acylated hormone, highly expressed in the stomach, which binds to its cognate receptor (GHSR1a) to regulate a plethora of relevant biological processes, including food intake, energy balance, hormonal secretions, learning, inflammation, etc. However, ghrelin is, in fact, the most notorious component of a complex, intricate regulatory system comprised of a growing number of alternative peptides (e.g. obestatin, unacylated ghrelin, and In1-ghrelin, etc.), known (GHSRs) and, necessarily unknown receptors, as well as modifying enzymes (e.g. ghrelin-O-acyl-transferase), which interact among them as well as with other regulatory systems in order to tightly modulate key (patho)-physiological processes. This multiplicity of functions and versatility of the ghrelin system arise from a dual, genetic and functional, complexity. Importantly, a growing body of evidence suggests that dysregulation in some of the components of the ghrelin system can lead to or influence the development and/or progression of highly concerning pathologies such as endocrine-related tumors, inflammatory/cardiovascular diseases, and neurodegeneration, wherein these altered components could be used as diagnostic, prognostic, or therapeutic targets. In this context, the aim of this review is to integrate and comprehensively analyze the multiple components and functions of the ghrelin system described to date in order to define and understand its biological and (patho)-physiological significance.
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Affiliation(s)
- Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, Campus Universitario de Rabanales, Edificio Severo Ochoa (C6), Planta 3, University of Córdoba, 14014-Córdoba; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), University of Córdoba; Reina Sofia University Hospital, Córdoba; and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
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