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Beckers AB, Weerts ZZRM, Helyes Z, Masclee AAM, Keszthelyi D. Review article: transient receptor potential channels as possible therapeutic targets in irritable bowel syndrome. Aliment Pharmacol Ther 2017; 46:938-952. [PMID: 28884838 DOI: 10.1111/apt.14294] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/06/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Abdominal pain in irritable bowel syndrome (IBS) remains challenging to treat effectively. Researchers have attempted to elucidate visceral nociceptive processes in order to guide treatment development. Transient receptor potential (TRP) channels have been implied in the generation (TRPV1, TRPV4, TRPA1) and inhibition (TRPM8) of visceral pain signals. Pathological changes in their functioning have been demonstrated in inflammatory conditions, and appear to be present in IBS as well. AIM To provide a comprehensive review of the current literature on TRP channels involved in visceral nociception. In particular, we emphasise the clinical implications of these nociceptors in the treatment of IBS. METHODS Evidence to support this review was obtained from an electronic database search via PubMed using the search terms "visceral nociception," "visceral hypersensitivity," "irritable bowel syndrome" and "transient receptor potential channels." After screening the abstracts the articles deemed relevant were cross-referenced for additional manuscripts. RESULTS Recent studies have resulted in significant advances in our understanding of TRP channel mediated visceral nociception. The diversity of TRP channel sensitization pathways is increasingly recognised. Endogenous TRP agonists, including poly-unsaturated fatty acid metabolites and hydrogen sulphide, have been implied in augmented visceral pain generation in IBS. New potential targets for treatment development have been identified (TRPA1 and TRPV4,) and alternative means of affecting TRP channel signalling (partial antagonists, downstream targeting and RNA-based therapy) are currently being explored. CONCLUSIONS The improved understanding of mechanisms involved in visceral nociception provides a solid basis for the development of new treatment strategies for abdominal pain in IBS.
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Affiliation(s)
- A B Beckers
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Limburg, The Netherlands
| | - Z Z R M Weerts
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Limburg, The Netherlands
| | - Z Helyes
- Department of Pharmacology and Pharmacotherapy, Molecular Pharmacology Research Team, University of Pécs Medical School, János Szentágothai Research Centre, University of Pécs, Pécs, Baranya, Hungary
| | - A A M Masclee
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Limburg, The Netherlands
| | - D Keszthelyi
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Limburg, The Netherlands
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Camilleri M, Bueno L, Andresen V, De Ponti F, Choi MG, Lembo A. Pharmacological, Pharmacokinetic, and Pharmacogenomic Aspects of Functional Gastrointestinal Disorders. Gastroenterology 2016; 150:S0016-5085(16)00220-1. [PMID: 27144621 DOI: 10.1053/j.gastro.2016.02.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/09/2016] [Indexed: 02/08/2023]
Abstract
This article reviews medications commonly used for the treatment of patients with functional gastrointestinal disorders. Specifically, we review the animal models that have been validated for the study of drug effects on sensation and motility; the preclinical pharmacology, pharmacokinetics, and toxicology usually required for introduction of new drugs; the biomarkers that are validated for studies of sensation and motility endpoints with experimental medications in humans; the pharmacogenomics applied to these medications and their relevance to the FGIDs; and the pharmacology of agents that are applied or have potential for the treatment of FGIDs, including psychopharmacologic drugs.
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Affiliation(s)
- Michael Camilleri
- Professor of Medicine, Pharmacology, and Physiology, Mayo Clinic College of Medicine, Consultant in Gastroenterology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Viola Andresen
- Israelitic Hospital, University of Hamburg, Orchideenstieg 14, Hamburg, Germany
| | - Fabrizio De Ponti
- Professor of Pharmacology, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Myung-Gyu Choi
- Professor of Gastroenterology, The Catholic University of Korea College of Medicine Internal Medicine , President, Korean Society of Neurogastroenterology and Motility , Seoul, Korea
| | - Anthony Lembo
- Associate Professor, Harvard Medical School, Director of the GI Motility Laboratory at the Beth Israel Deaconess Medical Center's (BIDMC) Division of Gastroenterology, Boston, MA, USA
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Bokic T, Storr M, Schicho R. Potential Causes and Present Pharmacotherapy of Irritable Bowel Syndrome: An Overview. Pharmacology 2015; 96:76-85. [PMID: 26139425 DOI: 10.1159/000435816] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 06/08/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is currently one of the most common disorders of the digestive system in the Western society. Almost 2 out of 10 people suffer from IBS with women being more affected than men. IBS is associated with abdominal pain, bloating and altered stool consistency and imposes a heavy burden for the affected patients. SUMMARY The pathophysiology of IBS remains elusive although potential causes have been suggested, such as a deranged brain-gut signaling, hypersensitivity of visceral sensory afferent fibers, bacterial gastroenteritis, small intestinal bacterial overgrowth (SIBO), genetic alterations and food sensitivity. Targets for the pharmacotherapy of IBS include the serotonergic and opioidergic system, and the microbial population of the gut. Alternative therapies like traditional Chinese medicine have shown some success in the combat against IBS. Key Messages: Many therapeutics for the treatment of IBS have emerged in the past; however, only a few have met up with the expectations in larger clinical trials. Additionally, the multifactorial etiology of IBS and its variety of cardinal symptoms requires an individual set of therapeutics. This review provides a short overview of potential causes and current pharmacological therapeutics and of additional and alternative therapies for IBS.
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Affiliation(s)
- Theodor Bokic
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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Mulak A, Larauche M, Biraud M, Million M, Rivier J, Taché Y. Selective agonists of somatostatin receptor subtype 1 or 2 injected peripherally induce antihyperalgesic effect in two models of visceral hypersensitivity in mice. Peptides 2015; 63:71-80. [PMID: 25451334 PMCID: PMC4385413 DOI: 10.1016/j.peptides.2014.10.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 02/08/2023]
Abstract
Somatostatin interacts with five G-protein-coupled receptor (sst1-5). Octreotide, a stable sst2≫3≥5 agonist, exerts a visceral anti-hyperalgesic effect in experimental and clinical studies. Little is known on the receptor subtypes involved. We investigated the influence of the stable sst1-5 agonist, ODT8-SST and selective receptor subtype peptide agonists (3 or 10μg/mouse) injected intraperitoneally (ip) on visceral hypersensitivity in mice induced by repeated noxious colorectal distensions (four sets of three CRD, each at 55mmHg) or corticotropin-releasing factor receptor 1 agonist, cortagine given between two sets of graded CRD (15, 30, 45, and 60mmHg, three times each pressure). The mean visceromotor response (VMR) was assessed using a non-invasive manometry method and values were expressed as percentage of the VMR to the 1st set of CRD baseline or to the 60mmHg CRD, respectively. ODT8-SST (10μg) and the sst2 agonist, S-346-011 (3 and 10μg) prevented mechanically induced visceral hypersensitivity in the three sets of CRD, the sst1 agonist (10μg) blocked only the 2nd set and showed a trend at 3μg while the sst4 agonist had no effect. The selective sst2 antagonist, S-406-028 blocked the sst2 agonist but not the sst1 agonist effect. The sst1 agonist (3 and 10μg) prevented cortagine-induced hypersensitivity to CRD at each pressure while the sst2 agonist at 10μg reduced it. These data indicate that in addition to sst2, the sst1 agonist may provide a novel promising target to alleviate visceral hypersensitivity induced by mechanoreceptor sensitization and more prominently, stress-related visceral nociceptive sensitization.
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Affiliation(s)
- Agata Mulak
- Department of Medicine, CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Digestive Diseases Division at the University of California Los Angeles and VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA; Department of Gastroenterology and Hepatology, Wroclaw Medical University, Wroclaw, Poland
| | - Muriel Larauche
- Department of Medicine, CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Digestive Diseases Division at the University of California Los Angeles and VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Mandy Biraud
- Department of Medicine, CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Digestive Diseases Division at the University of California Los Angeles and VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Mulugeta Million
- Department of Medicine, CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Digestive Diseases Division at the University of California Los Angeles and VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Jean Rivier
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, CA, USA
| | - Yvette Taché
- Department of Medicine, CURE: Digestive Diseases Research Center and Oppenheimer Family Center for Neurobiology of Stress, Digestive Diseases Division at the University of California Los Angeles and VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
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Dickman R, Maradey-Romero C, Fass R. The role of pain modulators in esophageal disorders - no pain no gain. Neurogastroenterol Motil 2014; 26:603-10. [PMID: 24750261 DOI: 10.1111/nmo.12339] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 03/11/2014] [Indexed: 01/25/2023]
Abstract
Pain modulators have been primarily used for the management of functional esophageal disorders. Recently, these drugs have also been used for the management of other esophageal disorders, such as non-erosive reflux disease, the hypersensitive esophagus, and heartburn that is not responsive to proton pump inhibitor treatment. Several etiologies have been identified in patients with functional esophageal disorders, and these include esophageal hypersensitivity due to peripheral and/or central sensitisation, altered central processing of peripheral stimuli, altered autonomic activity, and psychological comorbidity such as depression and anxiety. Different antidepressants have been used as pain modulators and have demonstrated a beneficial effect on patients with the aforementioned esophageal disorders. Tricyclic antidepressants are the most commonly used class of drugs in clinical practice. Other antidepressants that have been used, some with more clinical success than others, include selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and trazodone. Other medications that have been used as pain modulators in esophageal disorders include adenosine antagonists, serotonin agonists, antiepileptics, and medications that ameliorate peripheral neuropathy. The mechanism by which many of the pain modulators confer their visceral analgesic effect remains to be fully elucidated. Regardless, their role and value in treating esophageal disorders have markedly increased in the last decade.
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Affiliation(s)
- R Dickman
- The Esophageal and Swallowing Center, Division of Gastroenterology and Hepatology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA
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Keszthelyi D, Troost FJ, Masclee AA. Irritable bowel syndrome: methods, mechanisms, and pathophysiology. Methods to assess visceral hypersensitivity in irritable bowel syndrome. Am J Physiol Gastrointest Liver Physiol 2012; 303:G141-54. [PMID: 22595988 DOI: 10.1152/ajpgi.00060.2012] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, characterized by recurrent abdominal pain or discomfort in combination with disturbed bowel habits in the absence of identifiable organic cause. Visceral hypersensitivity has emerged as a key hypothesis in explaining the painful symptoms in IBS and has been proposed as a "biological hallmark" for the condition. Current techniques of assessing visceral perception include the computerized barostat using rectal distensions, registering responses induced by sensory stimuli including the flexor reflex and cerebral evoked potentials, as well as brain imaging modalities such as functional magnetic resonance imaging and positron emission tomography. These methods have provided further insight into alterations in pain processing in IBS, although the most optimal method and condition remain to be established. In an attempt to give an overview of these methods, a literature search in the electronic databases PubMed and MEDLINE was executed using the search terms "assessment of visceral pain/visceral nociception/visceral hypersensitivity" and "irritable bowel syndrome." Both original articles and review articles were considered for data extraction. This review aims to discuss currently used modalities in assessing visceral perception, along with advantages and limitations, and aims also to define future directions for methodological aspects in visceral pain research. Although novel paradigms such as brain imaging and neurophysiological recordings have been introduced in the study of visceral pain, confirmative studies are warranted to establish their robustness and clinical relevance. Therefore, subjective verbal reporting following rectal distension currently remains the best-validated technique in assessing visceral perception in IBS.
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Affiliation(s)
- D Keszthelyi
- Top Institute Food and Nutrition, Wageningen, The Netherlands.
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Stengel A, Taché Y. Activation of somatostatin 2 receptors in the brain and the periphery induces opposite changes in circulating ghrelin levels: functional implications. Front Endocrinol (Lausanne) 2012; 3:178. [PMID: 23335913 PMCID: PMC3542632 DOI: 10.3389/fendo.2012.00178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 12/17/2012] [Indexed: 12/26/2022] Open
Abstract
Somatostatin is an important modulator of neurotransmission in the central nervous system and acts as a potent inhibitor of hormone and exocrine secretion and regulator of cell proliferation in the periphery. These pleiotropic actions occur through interaction with five G protein-coupled somatostatin receptor subtypes (sst(1) (-) (5)) that are widely expressed in the brain and peripheral organs. The characterization of somatostatin's effects can be investigated by pharmacological or genetic approaches using newly developed selective sst agonists and antagonists and mice lacking specific sst subtypes. Recent evidence points toward a divergent action of somatostatin in the brain and in the periphery to regulate circulating levels of ghrelin, an orexigenic hormone produced by the endocrine X/A-like cells in the rat gastric mucosa. Somatostatin interacts with the sst(2) in the brain to induce an increase in basal ghrelin plasma levels and counteracts the visceral stress-related decrease in circulating ghrelin. By contrast, stimulation of peripheral somatostatin-sst(2) signaling results in the inhibition of basal ghrelin release and mediates the postoperative decrease in circulating ghrelin. The peripheral sst(2)-mediated reduction of plasma ghrelin is likely to involve a paracrine action of D cell-derived somatostatin acting on sst(2) bearing X/A-like ghrelin cells in the gastric mucosa. The other member of the somatostatin family, named cortistatin, in addition to binding to sst(1) (-) (5) also directly interacts with the ghrelin receptor and therefore may simultaneously modulate ghrelin release and actions at target sites bearing ghrelin receptors representing a link between the ghrelin and somatostatin systems.
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Affiliation(s)
- Andreas Stengel
- Division Psychosomatic Medicine and Psychotherapy, Department of Medicine, Obesity Center Berlin, Charité, Universitätsmedizin BerlinBerlin, Germany
- *Correspondence: Andreas Stengel, Division Psychosomatic Medicine and Psychotherapy, Department of Medicine, Obesity Center Berlin, Charité, Universitätsmedizin Berlin, Luisenstr. 13a, 10117 Berlin, Germany. e-mail: ; Yvette Taché, Digestive Diseases Division, CURE: Digestive Diseases Research Center, Center for Neurobiology of Stress and Women’s Health, Department of Medicine, VA Greater Los Angeles Health Care System, University of California at Los Angeles, CURE Building 115, Room 117, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA. e-mail:
| | - Yvette Taché
- Digestive Diseases Division, CURE: Digestive Diseases Research Center, Center for Neurobiology of Stress and Women’s Health, Department of Medicine, VA Greater Los Angeles Health Care System, University of California at Los AngelesLos Angeles, CA, USA
- *Correspondence: Andreas Stengel, Division Psychosomatic Medicine and Psychotherapy, Department of Medicine, Obesity Center Berlin, Charité, Universitätsmedizin Berlin, Luisenstr. 13a, 10117 Berlin, Germany. e-mail: ; Yvette Taché, Digestive Diseases Division, CURE: Digestive Diseases Research Center, Center for Neurobiology of Stress and Women’s Health, Department of Medicine, VA Greater Los Angeles Health Care System, University of California at Los Angeles, CURE Building 115, Room 117, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA. e-mail:
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8
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Jee SR, Jung HK, Min BH, Choi KD, Rhee PL, Kang YW, Lee SI. [Guidelines for the treatment of functional dyspepsia]. Korean J Gastroenterol 2011; 57:67-81. [PMID: 21350319 DOI: 10.4166/kjg.2011.57.2.67] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Functional dyspepsia (FD) is defined as the presence of symptoms thought to originate in the gastroduodenal area, in the absence of any organic, systemic, or metabolic disease that is likely to explain the symptoms. Based on the available evidence and consensus opinion, thirteen consensus statements for the treatment of FD were developed using the modified Delphi approach. Proton pump inhibitor, prokinetics, and histamine 2 receptor antagonists are effective for the treatment of FD. Mucosal protecting agents, fundus relaxant, and drugs for visceral hypersensitivity can improve symptoms in FD. Antacids and antidepressants may help improving symptoms in FD. Comparing endoscopy with 'test and treat' of Helicobacter pylori, endoscopy may be more effective initial strategy for managing patients with FD in Korea given high incidence of gastric cancer and low cost of endoscopy. Helicobacter pylori eradication can be one of the therapeutic options for patients with FD. Psychotherapy is effective for those who have severe symptoms and refractoriness. Further studies are strongly needed to develop better treatment strategies for Korean patients with FD.
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Affiliation(s)
- Sam Ryong Jee
- Department of Internal Medicine, Inje University College of Medicine, Busan, Korea
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9
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Abstract
Irritable bowel syndrome (IBS) is characterized by chronic, recurrent abdominal pain and altered bowel habits and is currently defined by symptom criteria and the absence of detectable organic disease. The underlying pathophysiology remains incompletely understood. Despite considerable efforts by the scientific community and the pharmaceutical industry to develop novel pharmacological treatments aimed at chronic visceral pain, the traditional approach to identifying and evaluating novel drugs for this target have largely failed to translate into effective IBS treatments. However, several novel drugs aimed at normalizing bowel movements have produced clinical effects, not only on the primary target, but also on pain and discomfort. While some of the commonly used experimental animal models for the pain dimension of IBS have some face and construct validity, the predictive validity of most of the models is either unknown, or has been disappointing. A reverse translational approach is proposed, which is based on identification and characterization of brain endophenotypes in patients, followed by translation of these endophenotypes for pharmacological studies in rodent models.
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Affiliation(s)
- Daniel P Holschneider
- VA Greater Los Angeles Healthcare System, LA, CA, USA,Departments of Psychiatry and the Behavioral Sciences, Neurology, Cell & Neurobiology, Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Sylvie Bradesi
- VA Greater Los Angeles Healthcare System, LA, CA, USA,UCLA Center for Neurobiology of Stress, Departments of Medicine, Physiology and Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, USA,Author for correspondence:
| | - Emeran A Mayer
- VA Greater Los Angeles Healthcare System, LA, CA, USA,UCLA Center for Neurobiology of Stress, Departments of Medicine, Physiology and Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, USA
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10
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Abstract
PURPOSE OF REVIEW Somatostatin influences motility, secretion, and absorption and often has in vivo a modulating, indirect effect on target cells in the gastrointestinal tract. Knowledge on tissue-specific expression of the five somatostatin receptors (SSTRs), their capacities for internalization and downregulation, their subtype-specific intracellular messengers, and the possibility of forming functionally distinct homodimers or heterodimers, has further complicated the actual in-vivo mechanism of action of somatostatin. This review reports recent in-vivo and in-vitro studies on somatostatin effects on the gastrointestinal tract and pancreas, most of them using a new engineered animal model able to define specific roles of somatostatin and/or its receptor subtypes. RECENT FINDINGS SSTR2 knockout mice showed normal circulating gastrin and unchanged acid output, suggesting a high degree of plasticity behind gastric acid secretion. Intestinal inflammation significantly increased somatostatin mRNA in SSTR2 null compared to wild type suggesting that somatostatin mediates inflammation also in SSTR2 null mice. In pancreatic islets of SSTR1-5 null mice no variations of islet size, cellular organization or glucagon or insulin content was shown when compared with null SSTRs and control mice. SUMMARY Although none of the recent findings produced on somatostatin seem ready to be considered for clinical application, recent developments of animal models such as SSTR knockout mice have highlighted promising results to better understand the direct and indirect effects of somatostatin on gastrointestinal tract functions.
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Affiliation(s)
- Vito Domenico Corleto
- Digestive and Liver Disease, II School of Medicine, University La Sapienza, Rome, Italy.
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11
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Abstract
In irritable bowel syndrome, the main objectives of the treatment are the relief of abdominal pain then the improvement of bowel disturbances. Spasmolytic agents, or clays remain routinely the first line pharmacological options. The efficacy of dietary recommendations is not validated in most of the cases while dietary fibers, mainly insoluble fibers, may even worsen abdominal discomfort. In C-IBS, osmotic laxatives or macrogol are effective to improve colonic transit while loperamide and also colestyramine can be prescribed to reduce the number of stools of D-IBS patients. When the first line treatment fails to improve symptoms, antidepressants (tricyclic rather than SSRs) can be prescribed at lower doses than that recommended for depression. In meta-analysis, the odds ratio for pain relief varies from 2 to 4 and strongly depends on the patient's compliance to the treatment. Probiotics, pregabalin and even antibiotics (i.e neomycin, metronidazole or rifaximin), are possible new therapeutic options. Few clinical trials suggest that ramosetron (a new 5HT3 antagonist), octreotide, melatonin, or lidocain could be also discussed in the future. A non pharmacological therapeutic approach has to be considered, particularly in patients with severe symptoms, in combination with pharmacological treatment.
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Affiliation(s)
- P Ducrotté
- ADEN EA 4311/IFRMP 23, Département d'Hépato-Gastroentérologie et de Nutrition, CHRU, Hôpital Charles Nicolle, 1, rue de Germont, 76031 Rouen cedex, France.
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12
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Abstract
Irritable bowel syndrome is a functional gastrointestinal disorder affecting up to 3-15% of the general population in western countries. It is characterised by unexplained abdominal pain, discomfort, and bloating in association with altered bowel habits. The pathophysiology of irritable bowel syndrome is multifactorial involving disturbances of the brain-gut axis. The pathophysiology provides the rationale for pharmacotherapy: abnormal gastrointestinal motor functions, visceral hypersensitivity, psychosocial factors, autonomic dysfunction, and mucosal immune activation. Understanding the mechanisms, and their mediators or modulators including neurotransmitters and receptors have led to several therapeutic approaches including agents acting on the serotonin receptor or serotonin transporter system, antidepressants, novel selective anticholinergics, alpha-adrenergic agonists, opioid agents, cholecystokinin-antagonists, neurokinin-antagonists, somatostatin receptor agonists, corticotropin releasing factor antagonists, chloride channel activators, guanylate cyclase-c agonists, melatonin, atypical benzodiazepines, antibiotics, immune modulators and probiotics. The mechanisms and current evidence regarding efficacy of these agents are reviewed.
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Affiliation(s)
- M Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research, College of Medicine, Mayo Clinic, Charlton 8-110, 200 First St SW, Rochester, MN 55905, United States.
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Van Op den Bosch J, Adriaensen D, Van Nassauw L, Timmermans JP. The role(s) of somatostatin, structurally related peptides and somatostatin receptors in the gastrointestinal tract: a review. ACTA ACUST UNITED AC 2009; 156:1-8. [PMID: 19362110 DOI: 10.1016/j.regpep.2009.04.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Accepted: 04/05/2009] [Indexed: 12/19/2022]
Abstract
Extensive functional and morphological research has demonstrated the pivotal role of somatostatin (SOM) in the regulation of a wide variety of gastrointestinal activities. In addition to its profound inhibitory effects on gastrointestinal motility and exocrine and endocrine secretion processes along the entire gastrointestinal tract, SOM modulates several organ-specific activities. In contrast to these well-known SOM-dependent effects, knowledge on the SOM receptors (SSTR) involved in these effects is much less conclusive. Experimental data on the identities of the SSTRs, although species- and tissue-dependent, point towards the involvement of multiple receptor subtypes in the vast majority of gastrointestinal SOM-mediated effects. Recent evidence demonstrating the role of SOM in intestinal pathologies has extended the interest of gastrointestinal research in this peptide even further. More specifically, SOM is supposed to suppress intestinal inflammatory responses by interfering with the extensive bidirectional communication between mucosal mast cells and neurons. This way, SOM not only acts as a powerful inhibitor of the inflammatory cascade at the site of inflammation, but exerts a profound antinociceptive effect through the modulation of extrinsic afferent nerve fibres. The combination of these physiological and pathological activities opens up new opportunities to explore the potential of stable SOM analogues in the treatment of GI inflammatory pathologies.
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Affiliation(s)
- Joeri Van Op den Bosch
- Laboratory of Cell Biology & Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
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Abstract
Noncardiac chest pain (NCCP) affects approximately 1 quarter of the adult population in the United States. The pathophysiology of the disorder remains to be fully elucidated. Identified underlying mechanisms for esophageal pain include gastroesophageal reflux disease (GERD), esophageal dysmotility, and visceral hypersensitivity. Aggressive antireflux treatment has been the main therapeutic strategy for GERD-related NCCP. NCCP patients with or without spastic esophageal motor disorders are responsive to pain modulators. The value of botulinum toxin injection, endoscopic treatment for GERD, and antireflux surgery in alleviating NCCP symptoms is limited.
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Houghton LA, Cremonini F, Camilleri M, Busciglio I, Fell C, Cox V, Alpers DH, Dewit OE, Dukes GE, Gray E, Lea R, Zinsmeister AR, Whorwell PJ. Effect of the NK(3) receptor antagonist, talnetant, on rectal sensory function and compliance in healthy humans. Neurogastroenterol Motil 2007; 19:732-43. [PMID: 17727393 DOI: 10.1111/j.1365-2982.2007.00934.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Visceral hypersensitivity is important in the pathophysiology of irritable bowel syndrome and thus a target for modulation in drug development. Neurokinin (NK) receptors, including NK(3) receptors, are expressed in the motor and sensory systems of the digestive tract. The aim of this study was to compare the effects of two different doses (25 and 100 mg) of the NK(3) receptor antagonist, talnetant (SB223412) with placebo on rectal sensory function and compliance in healthy volunteers studied at two centres. Rectal barostat tests were performed on 102 healthy volunteers, randomized to receive either oral talnetant 25 or 100 mg or placebo over 14-17 days. Studies were performed on three occasions: day 1 immediately prior to 1st dose, day 1 4 h postdose, and after 14- to17-day therapy. Compliance, and pressure thresholds for first sensation, urgency, discomfort and pain were measured using ascending method of limits, and sensory intensity ratings for gas, urgency, discomfort and pain determined during four random phasic distensions (12, 24, 36 and 48 mmHg). Talnetant had no effect on rectal compliance, sensory thresholds or intensity ratings compared with placebo. In general, the results obtained at the two centres differed minimally, with intensity scores at one centre consistently somewhat lower. At the doses tested, talnetant has no effect on rectal compliance or distension-induced rectal sensation in healthy participants.
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Affiliation(s)
- L A Houghton
- Neurogastroenterology Unit, Wythenshawe Hospital, Academic Division of Medicine and Surgery, University of Manchester, Manchester, UK
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16
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Klooker TK, Kuiken SD, Lei A, Boeckxstaens GE. Effect of long-term treatment with octreotide on rectal sensitivity in patients with non-constipated irritable bowel syndrome. Aliment Pharmacol Ther 2007; 26:605-15. [PMID: 17661764 DOI: 10.1111/j.1365-2036.2007.03398.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Acute administration of octreotide reduces visceral perception and therefore has been suggested as potential treatment for irritable bowel syndrome. Whether prolonged treatment with octreotide also reduces visceral sensitivity and improves gastrointestinal symptoms remains, however, unknown. AIM To investigate the effect of a slow release preparation of octreotide on rectal sensitivity and symptoms in irritable bowel syndrome patients. METHODS Forty-six non-constipated irritable bowel syndrome patients (52% female, 19-63 years) participated. Before and after 8 weeks of treatment with octreotide (Sandostatin LAR 20 mg i.m.) or placebo, patients underwent a barostat study to assess the rectal sensitivity. During a 2-week run-in period and treatment, abdominal pain, defecation frequency, consistency and symptom relief were scored weekly. RESULTS Octreotide, but not placebo, significantly increased the threshold for first sensation. Thresholds for urge to defecate and discomfort/pain and rectal compliance were not altered by either treatment. Octreotide improved stool consistency compared with placebo (loose stools after eight weeks: octreotide: 52%, placebo: 81%, P < 0.05). In contrast, abdominal pain and defecation frequency were not affected. CONCLUSIONS Although the threshold of first rectal sensation increased and stool consistency improved, long-term treatment with octreotide, at least at the current dose used, has no visceral analgesic effect and fails to improve irritable bowel syndrome symptoms.
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Affiliation(s)
- T K Klooker
- Department of Gastroenterology and Hepatology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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17
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Abstract
Az irritábilis bél szindróma (IBS) kezelése a változatos tünetek, a társuló neuropszichiátriai kórképek miatt nem könnyű feladat. Bár számos, különböző támadáspontú szert alkalmazunk a betegség kezelésére, a mai napig kevés olyan gyógyszer van, amelynek hatékonyságáról, biztonságosságáról és tolerabilitásáról egyértelmű bizonyítékok állnak rendelkezésre. Az IBS multikauzális jellegéből adódóan a visceralis hiperszenzitivitással, a motilitással, az agy-bél tengely szabályozási zavaraival kapcsolatos kutatások eredményei, a folyamatokban központi szerepet játszó neurotranszmitterek, ezek receptorainak megismerése teremtette meg az új kezelési lehetőségek alapját. Bár napjainkban néhány gyógyszert (alosetron, tegaserod) már törzskönyveztek egyes országokban IBS-ben, az új készítményekkel kapcsolatban még több, nagy betegszámú vizsgálatra van szükség.
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Affiliation(s)
- István Pregun
- Semmelweis Egyetem, Altalános Orvostudományi Kar II. Belgyógyászati Klinika, Budapest.
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18
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Abstract
Irritable bowel syndrome (IBS) is a highly prevalent functional gastrointestinal disorder affecting up to 3-15% of the general population in Western countries. It is characterised by unexplained abdominal pain, discomfort and bloating in association with altered bowel habits. The pathophysiology of IBS is considered to be multifactorial, involving disturbances of the brain-gut-axis: IBS has been associated with abnormal gastrointestinal motor functions, visceral hypersensitivity, psychosocial factors, autonomic dysfunction and mucosal inflammation. Traditional IBS therapy is mainly symptom oriented and often unsatisfactory. Hence, there is a need for new treatment strategies. Increasing knowledge of brain-gut physiology, mechanisms, and neurotransmitters and receptors involved in gastrointestinal motor and sensory function have led to the development of several new therapeutic approaches. This article provides a systematic overview of recently approved or novel medications that show promise for the treatment of IBS; classification is based on the physiological systems targeted by the medication. The article includes agents acting on the serotonin receptor or serotonin transporter system, novel selective anticholinergics, alpha-adrenergic agonists, opioid agents, cholecystokinin antagonists, neurokinin antagonists, somatostatin receptor agonists, neurotrophin-3, corticotropin releasing factor antagonists, chloride channel activators, guanylate cyclase-c agonists, melatonin and atypical benzodiazepines. Finally, the role of probiotics and antibacterials in the treatment of IBS is summarised.
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Affiliation(s)
- Viola Andresen
- Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER) Program, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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19
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Abstract
BACKGROUND The importance of bi-directional brain-gut interactions in gastrointestinal illness is increasingly being recognized, most prominently in the area of functional gastrointestinal disorders. Numerous current and emerging therapies aimed at normalizing brain-gut interactions are a focus of interest, particularly for irritable bowel syndrome and functional dyspepsia. METHODS A literature search was completed for preclinical and clinical studies related to central modulation of gastrointestinal functions and published in English between 1980 and 2006. RESULTS Existing data, while sparse, support the use of different classes of antidepressant drugs, including tricyclics, and selective and non-selective serotonin reuptake inhibitors in irritable bowel syndrome. Serotonin receptor agonists and antagonists with peripheral and possibly central effects are effective in treating specific subtypes of irritable bowel syndrome. Based largely on theoretical and preclinical evidence, several novel compounds that selectively target receptors at multiple levels within the brain-gut axis such as neurokinin, somatostatin and corticotropin-releasing factor receptor antagonists are promising. CONCLUSIONS This review discusses the rationale for modulation of the brain-gut axis in the treatment of functional gastrointestinal disorders and highlights the most promising current and future therapeutic strategies.
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Affiliation(s)
- E A Mayer
- Department of Medicine, Center for Neurovisceral Sciences and Women's Health, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA.
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20
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Abstract
There is a need to have predictive biomarkers to test novel experimental medicines in functional gastrointestinal disorders. The human pharmacodynamic models and biomarkers pertaining to two important conditions are reviewed in a two-part article: functional dyspepsia (part I) and visceral pain (part II). With visceral pain models, the large coefficient of variation in sensation end points in human studies precludes definitive conclusions such as go/no go decisions or dose selection for phase IIb or III studies, unless very large numbers of patients are evaluated in phase IIA pharmacodynamic studies. This renders such pharmacological studies ambitious, or unachievable in a timely fashion. Moreover, the results of tests and clinical trials should be interpreted with greater knowledge of the drug pharmacokinetics, including the influence of CYP metabolism and potential drug interactions. Thus, it is important to identify valid biomarkers of visceral pain for the assessment of treatment response in pharmacodynamic studies. In this second part of a two-part article, we shall discuss the special challenges in developing medications for visceral pain and the general importance of including pharmacokinetic and pharmacogenomic studies in drug development programmes.
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Affiliation(s)
- V Andresen
- Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER) Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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21
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Camilleri M, Bueno L, de Ponti F, Fioramonti J, Lydiard RB, Tack J. Pharmacological and pharmacokinetic aspects of functional gastrointestinal disorders. Gastroenterology 2006; 130:1421-34. [PMID: 16678556 DOI: 10.1053/j.gastro.2005.08.062] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 08/05/2005] [Indexed: 02/06/2023]
Abstract
Medications are commonly used for the treatment of patients with functional gastrointestinal disorders. The general goal of this report is to review the pharmacokinetics and pharmacology of medications used in functional gastrointestinal disorders. Methods included literature review, consensus evaluation of the evidence for each topic assigned originally to 1 or 2 authors, and broader review at a harmonization session as part of the Rome III process. This report reviews the animal models that have been validated for the study of effects of pharmacologic agents on sensation and motility; the preclinical pharmacology, pharmacokinetics, and toxicology usually required for introduction of novel therapeutic agents; the biomarkers validated for studies of sensation and motility end points with experimental medications in humans; the pharmacogenomics applied to these medications and disorders; and the pharmacology of agents that are applied or have potential for treatment of functional gastrointestinal disorders, including psychopharmacologic agents. Clinician and basic investigators involved in the treatment or investigation of functional gastrointestinal disorders or disease models need to have a comprehensive understanding of a vast range of medications. It is anticipated that the interaction between investigators of basic science, basic and applied pharmacology, and clinical trials will lead to better treatment of these disorders.
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22
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Corleto VD, Severi C, Romano G, Tattoli I, Weber HC, Stridsberg M, Rindi G, Campanini N, Tomassoni F, Pagotto U, Coy DH, Jensen RT, Delle Fave G. Somatostatin receptor subtypes mediate contractility on human colonic smooth muscle cells. Neurogastroenterol Motil 2006; 18:217-25. [PMID: 16487413 DOI: 10.1111/j.1365-2982.2005.00752.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study demonstrates the expression of functional somatostatin receptor (sstr) subtypes in human circular and longitudinal colonic smooth muscle cells (SMC). Native somatostatin (SS) and sstr subtype-specific analogues were used to characterize the sstr subtypes present in both cell types by contraction/relaxation studies. Qualitative and quantitative mRNA analysis and immunohistochemistry of sstr subtypes were also carried out. sstr subtype 2 mRNA was expressed in circular SMC, and various levels of subtypes 1, 2 and 3 mRNA were expressed in longitudinal colonic SMC. Native SS and each subtype-specific analogue exerted a modest, but significant, contraction, although inhibition of carbachol-induced contraction (relaxation) was the main effect on SMC from both layers. CH-288, a sstr subtype 1-specific analogue, and octreotide, a sstr subtype 2-specific analogue, were the most effective relaxant analogues on longitudinal and circular SMC, respectively. sstr subtypes display a distinct expression pattern on human colonic SMC; on circular SMC, subtype 2 is the only sstr, whereas sstr subtypes 1, 2 and 3 are expressed on human SMC isolated from the longitudinal layer. The contractile effects of SS are mediated through sstr subtype 2 and sstr subtype 1 on circular and longitudinal human colonic SMC, respectively.
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Affiliation(s)
- V D Corleto
- Department of Digestive and Liver Diseases, 1st and 2nd Schools of Medicine, University 'La Sapienza', Rome, Italy.
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23
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Abstract
Visceral hypersensitivity is a consistent finding in a considerable proportion of patients with irritable bowel syndrome (IBS), and may provide a physiological basis for the development of IBS symptoms. In this study, we aimed to confirm the hypothesis that nitric oxide (NO) is involved in maintaining visceral hypersensitivity in IBS. Ten healthy volunteers (HV) and 12 IBS patients with documented hypersensitivity to rectal distension underwent a rectal barostat study. The effect of placebo and the specific NO synthase inhibitor NG -monomethyl-L-arginine (L-NMMA) on resting volume, rectal sensitivity to distension and rectal compliance was evaluated in a double-blind, randomized, cross-over fashion. NG -monomethyl-L-arginine did not alter resting volumes in HV or IBS patients. In HV, l-NMMA did not alter rectal sensory thresholds compared to placebo (45 +/- 3 and 46 +/- 3 mmHg, respectively). In contrast, L-NMMA significantly increased the threshold for discomfort/pain in IBS patients (placebo: 18 +/- 2, l-NMMA: 21 +/- 3 mmHg, P < 0.05). Rectal compliance was not affected by L-NMMA. Although NO does not seem to play a major role in normal rectal sensation or tone, we provide evidence that NO may be involved in the pathophysiology of visceral hypersensitivity in IBS.
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Affiliation(s)
- S D Kuiken
- Department of Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, The Netherlands
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24
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Cremonini F, Camilleri M, Gonenne J, Stephens D, Oenning L, Baxter K, Foxx-Orenstein A, Burton D. Effect of somatostatin analog on postprandial satiation in obesity. ACTA ACUST UNITED AC 2005; 13:1572-9. [PMID: 16222060 DOI: 10.1038/oby.2005.193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Altered satiation may impact postprandial symptoms and potentially change food intake in obesity. Our aim was to compare effects of octreotide and placebo on postprandial symptoms, satiation, and gastric volumes in obesity. RESEARCH METHODS AND PROCEDURES In a randomized, parallel-group, double-blind, placebo-controlled study, 26 obese but otherwise healthy participants received 100 mug of octreotide or placebo subcutaneously 30 minutes before each study. Studies were performed on 2 separate days and included validated non-invasive techniques: (99m)Tc-single photon emission computed tomography imaging to measure fasting stomach volume and gastric volume changes after 90 mL of water and 240 mL of Ensure and a standardized nutrient drink test to measure the maximum tolerated volume and postprandial symptoms. RESULTS Relative to placebo, octreotide increased gastric volume after 90 mL of water; however, fasting and gastric volume change post-Ensure and maximum tolerated volume of Ensure were not different. Octreotide decreased sensations of fullness (p = 0.035) and bloating (p = 0.05) and tended to reduce aggregate symptoms (p = 0.07) after the fully satiating meal. DISCUSSION In obese individuals, somatostatin analog significantly reduced postprandial sensations after a satiating meal without altering maximum tolerated meal volume or postnutrient gastric volume, suggesting an effect on upper gut sensation. The role of somatostatin as a permissive factor in the development of obesity by reducing postprandial sensations deserves further study.
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Affiliation(s)
- Filippo Cremonini
- Clinical Enteric Neuroscience Translational and Epidemiological Research Program, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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25
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Cremonini F, Houghton LA, Camilleri M, Ferber I, Fell C, Cox V, Castillo EJ, Alpers DH, Dewit OE, Gray E, Lea R, Zinsmeister AR, Whorwell PJ. Barostat testing of rectal sensation and compliance in humans: comparison of results across two centres and overall reproducibility. Neurogastroenterol Motil 2005; 17:810-20. [PMID: 16336496 DOI: 10.1111/j.1365-2982.2005.00709.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We assessed reproducibility of measurements of rectal compliance and sensation in health in studies conducted at two centres. We estimated samples size necessary to show clinically meaningful changes in future studies. We performed rectal barostat tests three times (day 1, day 1 after 4 h and 14-17 days later) in 34 healthy participants. We measured compliance and pressure thresholds for first sensation, urgency, discomfort and pain using ascending method of limits and symptom ratings for gas, urgency, discomfort and pain during four phasic distensions (12, 24, 36 and 48 mmHg) in random order. Results obtained at the two centres differed minimally. Reproducibility of sensory end points varies with type of sensation, pressure level and method of distension. Pressure threshold for pain and sensory ratings for non-painful sensations at 36 and 48 mmHg distension were most reproducible in the two centres. Sample size calculations suggested that crossover design is preferable in therapeutic trials: for each dose of medication tested, a sample of 21 should be sufficient to demonstrate 30% changes in all sensory thresholds and almost all sensory ratings. We conclude that reproducibility varies with sensation type, pressure level and distension method, but in a two-centre study, differences in observed results of sensation are minimal and pressure threshold for pain and sensory ratings at 36-48 mmHg of distension are reproducible.
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Affiliation(s)
- F Cremonini
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.) Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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26
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Abstract
The symptomatic management of irritable bowel syndrome (IBS) and functional dyspepsia, which often overlap, can be frustrating and difficult. Education and reassurance remain central for management although controlled trials are lacking. Psychological interventions may be useful in select patients but methodological inadequacies in clinical trials limit their interpretability. For symptom exacerbations, drug treatment is reasonable but no current treatment successfully targets the full symptom complex. Bulking agents are not of proven efficacy in IBS; they may improve constipation but worsen bloating and pain. Anticholinergics are of uncertain value in IBS. A meta-analysis of trials of smooth muscle relaxants for IBS has been reported to be positive but the quality of the trials included was poor. Antidepressants for IBS and functional dyspepsia appear to be efficacious based on the limited published evidence; both global symptoms and abdominal pain improve. Selective serotonin reuptake inhibitors (SSRIs) are of uncertain efficacy but anecdotally appear to be useful. Laxatives are not of proven efficacy in IBS. Loperamide improves diarrhea, but not abdominal pain in IBS. No drug is of proven efficacy for bloating. Acid suppression remains the mainstay of therapy for functional dyspepsia but the majority of patients do not have an adequate response. Promising drugs include new prokinetics for constipation-predominant IBS (e.g., tegaserod, a partial 5-HT4 agonist, prucalopride, a full 5-HT4 agonist, and dexloxiglumide, a cholecystokinin1 antagonist), agents for diarrhea-predominant IBS (e.g., 5-HT3 antagonists, alpha2 receptor agonists and corticotrophin receptor-1 antagonists), other visceral analgesics (e.g. tachykinin antagonists, opioid agonists) and in dyspepsia fundus relaxing agents (e.g., 5-HT1 agonists, tegaserod).
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Affiliation(s)
- Nicholas J Talley
- Department of Medicine, Universtity of Sydney, Nepean Hospital, Penrith, NSW 2751, Australia.
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27
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Kuiken SD, Tytgat GN, Boeckxstaens GE. Review article: drugs interfering with visceral sensitivity for the treatment of functional gastrointestinal disorders--the clinical evidence. Aliment Pharmacol Ther 2005; 21:633-51. [PMID: 15771750 DOI: 10.1111/j.1365-2036.2005.02392.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
At present, the concept of visceral hypersensitivity provides the leading hypothesis regarding the generation of symptoms in functional gastrointestinal disorders. This paper discusses the current clinical evidence for drugs that have been proposed to interfere with visceral sensitivity in functional gastrointestinal disorders. Several possible pharmacological targets have been identified to reduce visceral pain and to reverse the processes underlying the persistence of visceral hypersensitivity. However, most of the available evidence comes from experimental animal models and cannot simply be extrapolated to patients with functional gastrointestinal disorders. In this review, we selected five drug classes that have been shown to exhibit visceral analgesic properties in experimental studies, and of which data were available regarding their clinical efficacy. These included opioid substances, serotonergic agents, antidepressants, somatostatin analogues and alpha(2)-adrenergic agonists. Although clinical trials show a limited benefit, in particular for serotonergic agents, the evidence illustrating that these effects result from normalization of visceral sensation is currently lacking. Therefore, we conclude that the concept of targeting visceral hypersensitivity as a treatment for functional gastrointestinal disorders is still controversial. Future evaluations require patient selection based on the presence of visceral hypersensitivity and application of compounds that exhibit 'true' viscerosensory effects.
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Affiliation(s)
- S D Kuiken
- Department of Gastroenterology and Hepatology, Academic Medical Centre, 1105 AZ Amsterdam, The Netherlands
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28
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Affiliation(s)
- Sang In Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Yong-Dong Severance Hospital, Korea.
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29
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Abstract
To evaluate therapies available for the treatment of irritable bowel syndrome, and provide consensus recommendations for their use, a total of 51 double-blind clinical trials using bulking agents, prokinetics, antispasmodics, alosetron, tegaserod and antidepressants were selected. The quality of studies was assessed using 5-point scale. Meta-analyses were performed on all studies, and on 'high-quality studies'. The efficacy of fibre in the global irritable bowel syndrome symptoms relief (OR: 1.9; 95% CI:1.5-2.4) was lost after exclusion of low-quality trials (OR: 1.4; 95% CI: 1.0-2.0, P = 0.06). When excluding the low-quality trials, an improvement of global irritable bowel syndrome symptoms with all antispasmodics (OR: 2.1; 95% CI:1.8-2.9) was maintained only for octylonium bromide, but on the basis of only two studies. Antidepressants were effective (OR: 2.6, 95% CI: 1.9-3.5), even after exclusion of low-quality studies (OR: 1.9, 95% CI: 1.3-2.7). Alosetron (OR: 2.2; 95% CI: 1.9-2.6) and tegaserod (OR: 1.4; 95% CI: 1.2-1.5) showed a significant effect in women. We recommend the use of tegaserod for women with irritable bowel syndrome with constipation and alosetron for women with severe irritable bowel syndrome with diarrhoea. Antidepressants can be beneficial for irritable bowel syndrome with diarrhoea patients with severe symptoms. Loperamide can be recommended in painless diarrhoea. Evidence is weak to recommend the use of bulking agents in the treatment of irritable bowel syndrome with constipation.
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30
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Abstract
Pathophysiology of irritable bowel syndrome (IBS) is based upon multiple factors that have been organised in a comprehensive model centred around the brain-gut axis. The brain-gut axis encompasses nerve pathways linking the enteric and the central nervous systems and contains a large proportion of afferent fibres. Functionally and anatomically, visceral nerves are divided in to two categories: the parasympathetic pathways distributing to the upper gut through the vagi and to the hindgut, through the pelvic and pudendal nerves, and the sympathetic pathways, arising form the spinal cord and distributing to the midgut via the paravertebral ganglia. Several abnormalities of gut sensori-motor function have been described in patients with IBS. Abnormal motility patterns have been described at the intestinal and colonic levels. Changes in colonic motility are mainly related to bowel disturbances linked to IBS but do not correlate with pain. More recently, visceral hypersensitivity has been recognised as a main characteristic of patients with IBS. It is defined by an exaggerated perception of luminal distension of various segments of the gut and related to peripheral changes in the processing of visceral sensations as well as modulation of perception by centrally acting factors including mood and stress. Viscero-visceral reflexes link the two edges of the brain-gut axis and may account for the origin of symptoms in some pathological conditions. Recent advances in the understanding of the role of myenteric plexus allowed recognition of several neurotransmitters involved at the level of both the afferent and efferent pathways. Targeting the receptors of these neurotransmitters is a promising way for development of new treatments for IBS.
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Affiliation(s)
- Michel Delvaux
- Department of Internal Medicine and Digestive Pathology, CHU de Brabois, F-54511 Vandoeuvre-les-Nancy, France.
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31
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Abstract
Sensorimotor disorders of the stomach, small intestine and colon have a limited repertoire of clinical manifestations, and there is the potential for more than one mechanism to lead to symptoms. In many recent clinical trial programs of novel agents in neurogastroenterology, the emphasis has been primarily on symptom assessment of broad groups of patients identified by the Rome criteria. Drugs of potential value have fallen by the wayside with this approach. We propose the current paradigm is partly to blame; physiological testing should provide the basis for identifying more homogeneous populations and therapeutic targets within functional bowel disease, and this applies to the upper and lower gut. Here we summarize the evidence that certain biomarkers can, in a limited fashion, be used to predict the success of an experimental medicine in common disorders of gastrointestinal function, including the irritable bowel syndrome and functional dyspepsia. Although the current evidence is limited and is most convincingly demonstrated with examples of transit measurements (for loperamide, alosetron, tegaserod and piboserod), we perceive this paradigm that studies using validated and responsive biomarkers have an important role to play in drug development.
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Affiliation(s)
- M Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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32
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Abstract
Treatment of spastic motility disorders continues to be challenging. Therapeutic options remain limited due in part to our lack of understanding of the pathophysiology and significance of these disorders. Furthermore, most of therapeutic trials to date are hampered by the poorly designed nature of the study, including the small size of the trials and the lack of placebo arm. Most of the available information suggests that there seems to be an important dissociation between symptoms (chest pain/dysphagia) and esophageal dysmotility. Drug treatment aimed at visceral sensitivity seems more effective in relieving symptoms than spasmolytic medications. Recent trials with Botox, nitric oxide derivatives, and SSRIs offer promising results. Rigorous study design that includes large placebo-controlled trials is needed in this area.
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Affiliation(s)
- Sami R Achem
- Department of Gastroenterology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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33
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Abstract
Patients with chest pain of presumed esophageal origin should be reassured and should undergo an esophageal manometry study. In patients with spastic esophageal disorders, a trial with calcium channel blockers or low-dose antidepressants used as visceral analgesics is the best approach. Inpatients with non GERD-related, nonspastic esophageal motility disorder, low-dose antidepressants seem reasonable. Anxiolytics are useful in patients with panic disorders, and psychological interventions (eg, cognitive-behavioral therapy) are also valuable, mainly in patients in whom reassurance is not sufficient to avoid the misinterpretation of their symptoms. In the future, visceral sensitivity modifying agents such as serotoninergic agonists or antagonists may become the cornerstone of therapy in patients with chest pain of presumed esophageal origin. Combinations of different approaches, such as proton pump inhibitors and psychotropic or antinociceptive agents, should also be evaluated in clinical trials.
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Affiliation(s)
- Max J Schmulson
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City 14000, Mexico.
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34
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Schwetz I, Naliboff B, Munakata J, Lembo T, Chang L, Matin K, Ohning G, Mayer EA. Anti-hyperalgesic effect of octreotide in patients with irritable bowel syndrome. Aliment Pharmacol Ther 2004; 19:123-31. [PMID: 14687174 DOI: 10.1111/j.1365-2036.2004.01774.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Octreotide has been found to be beneficial in the treatment of chronic pain, although the mechanisms underlying its therapeutic effect are incompletely understood. AIMS To assess the effect of octreotide on perceptual responses to rectal distension in irritable bowel syndrome patients and healthy controls at baseline and following the experimental induction of rectal hyperalgesia. METHODS In study 1, rectal perception thresholds for discomfort were determined in seven irritable bowel syndrome patients and eight healthy controls on three separate days using a computer-controlled barostat. Subjects received saline, low-dose and high-dose octreotide in a random double-blind fashion. In study 2, perceptual responses to rectal distension were obtained in nine irritable bowel syndrome patients and seven controls before and after repetitive high-pressure mechanical sigmoid stimulation. RESULTS Octreotide increased the discomfort thresholds in irritable bowel syndrome patients, but not in controls, without changing rectal compliance. Repetitive sigmoid stimulation resulted in decreased rectal discomfort thresholds in the patient group only. In irritable bowel syndrome patients, octreotide prevented the sensitizing effect of repetitive sigmoid stimulation on rectal discomfort thresholds. CONCLUSIONS Octreotide effectively increased discomfort thresholds in irritable bowel syndrome patients, but not in controls, at baseline and during experimentally induced rectal hyperalgesia. These findings suggest that octreotide exerts primarily an anti-hyperalgesic rather than analgesic effect on visceral perception.
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Affiliation(s)
- I Schwetz
- CNS/WH: Center for Neurovisceral Sciences and Women's Health, Los Angeles, CA 90073, USA
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35
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Abstract
Colonic motility disorders are common conditions. However, our understanding of normal, and, consequently, pathological motor function of the colon remains limited, mainly due to the relative inaccessibility of this organ for study. Investigation of colonic motility may encompass one or more of the four separate components (myoelectric activity, phasic and tonic contractile activity and movement of intraluminal content) using electrophysiological, manometric or transit studies. Although transit studies provide the best 'functional' appreciation of colonic motor activity, and are the only techniques used in contemporary clinical practice, manometric methods are becoming increasingly popular, as they allow a direct study of colonic contractile activity over prolonged periods. To date, the majority of studies have been limited to the pelvic colon by a retrograde (per rectal) approach; however, recent technological advances have facilitated 'pan-colonic' investigation. This review concentrates on manometry of the human colon proximal to the sigmoid, and includes evaluation of both phasic and tonic motor activity, by utilization of perfused-tube and solid-state manometric catheters, and also the electronic barostat. Methodological techniques, experimental protocols and the analysis and interpretation of recorded data are critically explored, and a contemporary classification of colonic contractile activities is presented.
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Affiliation(s)
- S M Scott
- Academic Department of Surgery, GI Physiology Unit, Barts and the London, Queen Mary School of Medicine & Dentistry, The Royal London Hospital, Whitechapel, London, UK.
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Humphrey P, Hicks G, Feniuk W, Schindler M. Somatostatin Receptors in Analgesia. Pain 2003. [DOI: 10.1201/9780203911259.ch55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kuiken SD, Tytgat GN, Boeckxstaens GE. The selective serotonin reuptake inhibitor fluoxetine does not change rectal sensitivity and symptoms in patients with irritable bowel syndrome: A double blind, randomized, placebo-controlled study. Clin Gastroenterol Hepatol 2003. [DOI: 10.1016/s1542-3565(03)70039-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Abstract
The management of the irritable bowel syndrome (IBS) remains unsatisfactory. For abdominal pain, antispasmodics are, at best, of only modest efficacy. Tricyclic antidepressants in low dose are useful (with the number needed to treat being three), but side effects and patient concerns regarding use of a centrally acting agent for depression remain limitations. Selective serotonin reuptake inhibitors are of uncertain efficacy in IBS. Opioid agonists, especially loperamide, are useful for diarrhea but not for pain in IBS; rebound constipation also remains a problem. Bile salt sequestering agents are not of established value in IBS but seem to be useful clinically in a small group of IBS patients with diarrhea. Aloestron, a 5HT(3) antagonist, should be reserved, if available, for women with severe diarrhea predominant IBS who have failed to respond to conventional therapy, and started at a low dose. Fiber and bulking agents may help constipation in some trials, but the evidence that they are efficacious in IBS is equivocal; they are frequently prescribed as first-line drugs for IBS regardless of the primary bowel disturbance but often increase bloating, gas, and pain. Laxatives are not of established value in IBS but are often taken by patients with constipation predominant IBS. Tegaserod, a partial 5HT(4) agonist, is now available in the United States and other countries for use in women with IBS whose primary bowel symptom is constipation; its efficacy in men and in those with alternating bowel habits is unknown. Probiotics are of uncertain efficacy. Chinese herbal medicine data are insufficient. Other new drugs in development include the cholecystokinin antagonists and novel visceral analgesics. Both current and potential therapies for IBS are reviewed in this article.
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Affiliation(s)
- Nicholas J Talley
- Mayo Clinic Rochester, Charlton Building 8-110, 200 First Street, S.W., Rochester, MN 55905, USA
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Abstract
Irritable bowel syndrome (IBS), a functional gastrointestinal disorder, is present in 10% to 20% of the U.S. adult population. The syndrome is best defined as chronic abdominal discomfort with changes in stool frequency, consistency, and passage, with associated symptoms such as abdominal bloating or presence of mucus in stools. Several studies have shown that up to 70% to 90% of patients with IBS who seek treatment have psychiatric comorbidity, most notably mood and anxiety disorders. Recent studies have shown a high prevalence of IBS in psychiatric patients who seek treatment, with a prevalence of 19% in schizophrenia, 29% in major depression, and 46% in panic disorder among other disorders. Our article reviews the comorbidity of IBS in psychiatric patients and discusses implications for treatment.
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Affiliation(s)
- Amir Garakani
- Department of Psychiatry, Mt. Sinai School of Medicine, New York, NY, USA
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Abstract
In recent years there has been an increasing appreciation of the complexity of functional gastrointestinal disorders. These represent a spectrum of conditions which may affect any part of the gastrointestinal tract in which there appears to be dysregulation of visceral function and afferent sensation and a strong association with emotional factors and stress. There is a clear psychological dimension, with up to 60% of irritable bowel syndrome (IBS) patients reported to have psychological co-morbidities and altered pain perception is also common in comparison with control populations. The role of the enteric nervous system, the sensory pathways and the brain as well as the influence of the latter on sympathetic and parasympathetic outflow have likewise attracted increasing interest and have led to exciting new methods to study their complex interactions. The concept of low-grade inflammation, such as might occur after infection, acting as a trigger for neuromuscular dysfunction has also led to the broad integrative hypotheses that help to explain the biopsychosocial dimensions seen in functional gastrointestinal disease. The multi-component model places a major emphasis on neurogastroenterology and enteric and neuro-immune interactions where new approaches to pharmacotherapy lie. Drugs may affect motility, visceral sensation and other aspects of gut function such as secretion or absorption. More particularly, however, has been the search for and attempts to influence important mediators of these primary gut functions. Such targets include serotonin and selected 5-HT receptors, which are involved in gut motility, visceral sensation and other aspects of gut function, CCK receptors which are involved in the mediation of pain in the gut and nociception in the CNS, opioid receptors involved in pain in the brain, spinal cord and periphery, muscarinic M3-receptors, substance P and neurokinin A and B receptors which are involved in motor adaptation and pain transmission in association with inflammation, gabba receptors involved in nociception and cannabinoid receptors which are involved in the control of acetyl choline release in the gut. With a better understanding of the structures and pathways involved in visceral perception and hyperalgesia, in the CNS, spinal cord and the gut and new pharmacological tools we will be better able to elucidate the neuropharmacology of visceral perception and its relationship to gut dysfunction. It is likely that there will be multiple therapeutic options based on the spectrum of abnormalities capable of causing the spectrum of symptoms of functional gastrointestinal disorders in any individual patient.
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Affiliation(s)
- Richard H Hunt
- Department of Medicine, Division of Gastroenterology, McMaster University Medical Centre, Hamilton, Ontario, Canada
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van Bergeijk JD, Wilson JHP, Nielsen OH, von Tirpitz C, Karvonen AL, Lygren I, Rädler A, Waldum HL, Mulder CJJ, Friis S, Tefera S, Hoogkamer JFW. Octreotide in patients with active ulcerative colitis treated with high dose corticosteroids (OPUS 1). Eur J Gastroenterol Hepatol 2002; 14:243-8. [PMID: 11953688 DOI: 10.1097/00042737-200203000-00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND In ulcerative colitis the intestinal somatostatin content is reduced. Somatostatin has several immune-inhibitory effects. In vitro it diminishes activity of intestinal lymphocytes and peripheral blood monocytes. Its long-acting analogue octreotide has beneficial effects on mucosal damage in acute experimental acetic acid colitis in rats. AIMS To determine the potential benefits of octreotide as a treatment for patients with severe ulcerative colitis treated with high dose corticosteroids. PATIENTS Forty-two patients with severe ulcerative colitis (more than 10 points on the Powell-Tuck scoring system and mucosal disease Heatly grade III or IV). METHODS In a multi-centre, double blind, placebo-controlled trial all patients were treated with oral 5-ASA (1.6-2.4 g daily) and high dose corticosteroids (tapering off from 60 to 80 mg daily). They were randomly assigned to receive subcutaneous placebo (n = 22) or octreotide 500 microg (n = 20) thrice daily during 21 days. Clinical and endoscopic disease activity, histology and laboratory parameters were obtained during the study period. RESULTS Clinical disease activity for both octreotide and placebo were not significantly different at baseline and after 21 days of treatment. Endoscopic disease activities (mean +/- SD) changed from 12.5 +/- 4.7 to 7.2 +/- 5.3 for octreotide, and from 11.5 +/- 5.0 to 5.0 +/- 3.4 for placebo (NS). Seven patients from both groups received additional treatment (colectomy (n = 6), cyclosporin (n = 1)). Adverse events occurred equally in both groups. CONCLUSIONS Subcutaneous administration of octreotide 500 microg thrice daily is not of additional benefit as adjuvant therapy to high dose corticosteroids in severe ulcerative colitis.
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Affiliation(s)
- Jeroen D van Bergeijk
- Dept of Gastroenterology and Internal Medicine, University Hospital Rotterdam, The Netherlands
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Affiliation(s)
- Carlo Di Lorenzo
- Division of Pediatric Gastroenterology, Children's Hospital of Pittsburgh, University of Pittsburgh, Pennsylvania 15213, USA.
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Abstract
Irritable bowel syndrome (IBS) is common and can be disabling. Several drugs that modulate serotonin (5HT) and other neurotransmitters in the gut (neuroenteric modulators) have either become available or are in development, but progress has been slowed by toxicity. Blockade of 5HT(3) receptors slows colonic transit, increases fluid absorption and increases left colon compliance. Alosetron, a potent 5HT(3) receptor antagonist, has, in women but not in men, a clinically significant but modest therapeutic gain over placebo in the relief of abdominal pain and discomfort and bowel-habit disturbance (but not bloating) in diarrhoea-predominant IBS. However, the drug unexpectedly was associated with ischaemic colitis and, very rarely, severe constipation-induced complications, and alosetron has been withdrawn. Cilansetron may have similar efficacy in men and women. 5HT(4) receptor stimulation results in accelerated colonic transit, and tegaserod, a partial 5HT(4) receptor agonist, has modest but clinically significant advantage over placebo in constipation-predominant IBS; the benefit seems to be confined to females. Long-term published data are lacking and safety concerns have been raised. Prucalopride, a full 5HT(4) agonist that has been promising in idiopathic chronic constipation, may also be limited by toxicity. Other 5HT receptor antagonists and agonists are under development for IBS. However, for modulators of single receptors to achieve a substantial therapeutic gain, and to do so safely, drug targets based on the pathophysiology of IBS need to be better defined.
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Affiliation(s)
- N J Talley
- Department of Medicine, University of Sydney, Nepean Hospital, PO Box 63, NSW 2751, Penrith, Australia.
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Abstract
An intricate surveillance network consisting of enteroendocrine cells, immune cells and sensory nerve fibres monitors the luminal and interstitial environment in the alimentary canal. Functional bowel disorders are characterized by persistent alterations in digestive regulation and gastrointestinal discomfort and pain. Visceral hyperalgesia may arise from an exaggerated sensitivity of peripheral afferent nerve fibres and/or a distorted processing and representation of gut signals in the brain. Novel strategies to treat these sensory bowel disorders are therefore targeted at primary afferent nerve fibres. These neurons express a number of molecular traits including transmitters, receptors and ion channels that are specific to them and whose number and/or behaviour may be altered in chronic visceral pain. The targets under consideration comprise vanilloid receptor ion channels, acid-sensing ion channels, sensory neuron-specific Na(+) channels, P2X(3) purinoceptors, 5-hydroxytryptamine (5-HT), 5-HT(3) and 5-HT(4) receptors, cholecystokinin CCK(1) receptors, bradykinin and prostaglandin receptors, glutamate receptors, tachykinin and calcitonin gene-related peptide receptors as well as peripheral opioid and cannabinoid receptors. The utility of sensory neuron-targeting drugs in functional bowel disorders will critically depend on the compounds' selectivity of action for afferent versus enteric or central neurons.
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Affiliation(s)
- P Holzer
- Department of Experimental and Clinical Pharmacology, University of Graz, Universitätsplatz 4, A-8010 Graz, Austria.
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Müller-Lissner SA, Fumagalli I, Bardhan KD, Pace F, Pecher E, Nault B, Rüegg P. Tegaserod, a 5-HT(4) receptor partial agonist, relieves symptoms in irritable bowel syndrome patients with abdominal pain, bloating and constipation. Aliment Pharmacol Ther 2001; 15:1655-66. [PMID: 11564007 DOI: 10.1046/j.1365-2036.2001.01094.x] [Citation(s) in RCA: 330] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AIM To investigate the efficacy and safety of tegaserod, a novel 5-HT(4) receptor partial agonist, in a randomized, double-blind, placebo-controlled, 12-week treatment, multicentre study. METHODS Eight hundred and eighty-one patients with irritable bowel syndrome, characterized by abdominal pain, bloating and constipation, received tegaserod, 2 mg b.d. or 6 mg b.d., or placebo for 12 weeks. RESULTS Tegaserod, 2 mg b.d. and 6 mg b.d., showed a statistically significant relief of overall irritable bowel syndrome symptoms, measured by a weekly, self-administered questionnaire. At end-point, treatment differences from placebo were 12.7% and 11.8% for 2 mg b.d. and 6 mg b.d., respectively. The effect of tegaserod was noted as early as week 1, and was sustained over the 12-week treatment period. Individual irritable bowel syndrome symptoms assessed daily also showed a statistically significant improvement of abdominal discomfort/pain, number of bowel movements and stool consistency, and a favourable trend for reducing days with significant bloating. Adverse events were similar in all groups, with transient diarrhoea being the only adverse event seen more frequently with tegaserod than placebo. CONCLUSIONS Based upon the results of this study, tegaserod offers rapid and sustained relief of the abdominal pain and constipation associated with irritable bowel syndrome. Tegaserod is also well tolerated.
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Abstract
The optimal "treatment" of postfundoplication complications is preoperative prevention of them. Nonreflux causes of the symptom prompting surgery should be carefully eliminated preoperatively. Failure to respond to optimal powerful antireflux pharmacotherapy suggests that GERD was not the cause of symptoms. Neurologic or respiratory disease, delayed gastric emptying or retching, short esophagus, and esophageal dysmotility may predispose patients to complications, and may require careful tailoring of the fundoplication. The optimal antireflux surgery, with a wrap neither too loose nor too tight, may require a nadir lower esophageal sphincter pressure of more than 5 mm Hg to prevent reflux, but less than some value to prevent dysphagia. This latter value may be approximately 10 mm Hg, but depends on swallowing parameters such as peristaltic pressure, lower esophageal sphincter opening diameter, swallowed bolus diameter, and other considerations. Infants may require a gastrostomy tube for venting because of their lower gastric compliance to deal with swallowed air. Children with delayed gastric emptying may benefit from pyloroplasty, but this is debated. When complications occur, re-evaluate the diagnosis and the competence of the fundoplication with barium fluoroscopy, endoscopy with histology, pH probe, and other modalities as indicated. Initially try conservative management of the patient's complications, including dietary and feeding modifications. Give a trial of antireflux pharmacotherapy for recurrent reflux or pharmacotherapy directed at the specific side-effect of the fundoplication if one is present. Consider endoscopically dilating a persistently tight wrap or surgically revising the fundoplication if it is suggested by the evaluation.
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Affiliation(s)
- Susan R. Orenstein
- Pediatric Gastroenterology, Children's Hospital of Pittsburgh, One Children's Place, Pittsburgh, PA 15213-2583, USA.
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Booth CE, Kirkup AJ, Hicks GA, Humphrey PP, Grundy D. Somatostatin sst(2) receptor-mediated inhibition of mesenteric afferent nerves of the jejunum in the anesthetized rat. Gastroenterology 2001; 121:358-69. [PMID: 11487545 DOI: 10.1053/gast.2001.26335] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Octreotide inhibits visceral sensations in clinical studies, but the site of action and the receptor type(s) involved are unknown. Our aim was to investigate the effects of octreotide, the selective sst(2) receptor agonist (BIM 23027), and the sst(2) antagonist (Cyanamid154806) on the activity of mesenteric afferent fibers innervating the rat jejunum. Their effects were investigated on baseline discharge, mechanosensitivity, and responses to algesic chemicals. METHODS Extracellular multiunit recordings of jejunal afferent nerve firing were made in pentobarbitone-anesthetized (60 mg/kg intraperitoneally) male Wistar rats. RESULTS Octreotide and BIM23027 (0.001-100 microg/kg intravenously) each evoked a long-lasting inhibition of baseline discharge, which was blocked by cyanamid 154806 (3 mg/kg) and absent in chronically vagotomized animals. Afferent responses to bradykinin were also inhibited by an sst(2) receptor-mediated mechanism but were unaffected by vagotomy. Ramp distentions of the jejunum evoked a biphasic activation of afferent nerve discharge, the low threshold component of which was attenuated in vagotomized animals. Sst(2) receptor agonists significantly inhibited the mechanosensitivity of spinal, but not vagal, afferents. CONCLUSIONS These data suggest that activation of somatostatin sst(2) receptors inhibit populations of mesenteric afferents likely to be involved in nociceptive transmission.
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Affiliation(s)
- C E Booth
- Department of Biomedical Science, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield, S10 2TN England
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Abstract
BACKGROUND Functional dyspepsia is defined by upper gastrointestinal symptoms without any evidence of structural abnormalities or organic disease. Current pharmacological treatment of functional dyspepsia is largely empirical and involves anti-secretory or prokinetic drugs. AIMS To review recent advances in the understanding of the mechanisms involved in symptom production in functional dyspepsia, as well as the development of new drugs that may interfere with these mechanisms, which may lead to more rational and effective treatment of this clinical condition. METHOD Systematic review of papers published in English for the last 10 years. RESULTS New drugs that increase propulsive gastroduodenal motor activity include new benzamides similar to cisapride, CCK-A blockers, agonists of opiate receptors and motilin agonists similar to erythromycin. A number of agents, including sumatriptan and buspirone, stimulates serotonin receptors in the myoenteric plexuses and have been shown to increase gastric accommodation to a meal. Finally, a number of new drugs that either increase thresholds for visceral perception or modify sensations is currently under investigation. This includes agents of several groups, such as octreotide, loxiglumide, ondansetron and other serotonin blockers, fedotozine and tricyclic antidepressant at low doses. CONCLUSIONS Although these new drugs may improve the pharmacological approach to the treatment of functional dyspepsia, there is a need for randomized, controlled trials to assess their efficacy. Moreover, difficulties related to the identification of the mechanisms underlying symptoms may limit the utilization of these new drugs.
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Affiliation(s)
- L E Troncon
- Departamento de Clínica Médica (Divisão de Gastroenterologia), Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP.
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