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Do HQ, Jansen M. Binding motif for RIC-3 chaperon protein in serotonin type 3A receptors. J Gen Physiol 2023; 155:e202213305. [PMID: 37026993 PMCID: PMC10083716 DOI: 10.1085/jgp.202213305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/09/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
Serotonin or 5-hydroxytryptamine type 3 (5-HT3) receptors belong to the family of pentameric ligand-gated ion channels (pLGICs) that are therapeutic targets for psychiatric disorders and neurological diseases. Due to structural conservation and significant sequence similarities of pLGICs' extracellular and transmembrane domains, clinical trials for drug candidates targeting these two domains have been hampered by off-subunit modulation. With the present study, we explore the interaction interface of the 5-HT3A subunit intracellular domain (ICD) with the resistance to inhibitors of choline esterase (RIC-3) protein. Previously, we have shown that RIC-3 interacts with the L1-MX segment of the ICD fused to maltose-binding protein. In the present study, synthetic L1-MX-based peptides and Ala-scanning identify positions W347, R349, and L353 as critical for binding to RIC-3. Complementary studies using full-length 5-HT3A subunits confirm that the identified Ala substitutions reduce the RIC-3-mediated modulation of functional surface expression. Additionally, we find and characterize a duplication of the binding motif, DWLR…VLDR, present in both the MX-helix and the transition between the ICD MA-helix and transmembrane segment M4. Analogous Ala substitutions at W447, R449, and L454 disrupt MAM4-peptide RIC-3 interactions and reduce modulation of functional surface expression. In summary, we identify the binding motif for RIC-3 in 5-HT3A subunits at two locations in the ICD, one in the MX-helix and one at the MAM4-helix transition.
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Affiliation(s)
- Hoa Quynh Do
- Department of Cell Physiology and Molecular Biophysics and Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Michaela Jansen
- Department of Cell Physiology and Molecular Biophysics and Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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Understanding the Connection between Gut Homeostasis and Psychological Stress. J Nutr 2023; 153:924-939. [PMID: 36806451 DOI: 10.1016/j.tjnut.2023.01.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 12/24/2022] [Accepted: 01/17/2023] [Indexed: 02/03/2023] Open
Abstract
Long-term exposure to adverse life events that provoke acute or chronic psychological stress (hereinafter "stress") can negatively affect physical health and even increase susceptibility to psychological illnesses, such as anxiety and depression. As a part of the hypothalamic-pituitary-adrenal axis, corticotropin-releasing factor (CRF) released from the hypothalamus is primarily responsible for the stress response. Typically, CRF disrupts the gastrointestinal system and leads to gut microbiota dysbiosis, thereby increasing risk of functional gastrointestinal diseases, such as irritable bowel syndrome. Furthermore, CRF increases oxidative damage to the colon and triggers immune responses involving mast cells, neutrophils, and monocytes. CRF even affects the differentiation of intestinal stem cells (ISCs), causing enterochromaffin cells to secrete excessive amounts of 5-hydroxytryptamine (5-HT). Therefore, stress is often accompanied by damage to the intestinal epithelial barrier function, followed by increased intestinal permeability and bacterial translocation. There are multi-network interactions between the gut microbiota and stress, and gut microbiota may relieve the effects of stress on the body. Dietary intake of probiotics can provide energy for ISCs through glycolysis, thereby alleviating the disruption to homeostasis caused by stress, and it significantly bolsters the intestinal barrier, alleviates intestinal inflammation, and maintains endocrine homeostasis. Gut microbiota also directly affect the synthesis of hormones and neurotransmitters, such as CRF, 5-HT, dopamine, and norepinephrine. Moreover, the Mediterranean diet enhances the stress resistance to some extent by regulating the intestinal flora. This article reviews recent research on how stress damages the gut and microbiota, how the gut microbiota can improve gut health by modulating injury due to stress, and how the diet relieves stress injury by interfering with intestinal microflora. This review gives insight into the potential role of the gut and its microbiota in relieving the effects of stress via the gut-brain axis.
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Singh M, Kumar V, Sehrawat N, Yadav M, Chaudhary M, Upadhyay SK, Kumar S, Sharma V, Kumar S, Dilbaghi N, Sharma AK. Current paradigms in epigenetic anticancer therapeutics and future challenges. Semin Cancer Biol 2021; 83:422-440. [PMID: 33766649 DOI: 10.1016/j.semcancer.2021.03.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/14/2020] [Accepted: 03/16/2021] [Indexed: 12/16/2022]
Abstract
Any alteration at the genetic or epigenetic level, may result in multiplex of diseases including tumorigenesis which ultimately results in the cancer development. Restoration of the normal epigenome by reversing the epigenetic alterations have been reported in tumors paving the way for development of an effective epigenetic treatment in cancer. However, delineating various epigenetic events has been a challenging task so far despite substantial progress in understanding DNA methylation and histone modifications during transcription of genes. Many inhibitors in the form of epigenetic drugs mostly targeting chromatin and histone modifying enzymes including DNA methyltransferase (DNMT) enzyme inhibitors and a histone deacetylases (HDACs) inhibitor, have been in use subsequent to the approval by FDA for cancer treatment. Similarly, other inhibitory drugs, such as FK228, suberoylanilide hydroxamic acid (SAHA) and MS-275, have been successfully tested in clinical studies. Despite all these advancements, still we see a hazy view as far as a promising epigenetic anticancer therapy is concerned. The challenges are to have more specific and effective inhibitors with negligible side effects. Moreover, the alterations seen in tumors are not well understood for which one has to gain deeper insight into the tumor pathology as well. Current review focusses on such epigenetic alterations occurring in cancer and the effective strategies to utilize such alterations for potential therapeutic use and treatment in cancer.
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Affiliation(s)
- Manoj Singh
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Vikas Kumar
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Nirmala Sehrawat
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Mukesh Yadav
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Mayank Chaudhary
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Sushil K Upadhyay
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Sunil Kumar
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India
| | - Varruchi Sharma
- Department of Biotechnology, Sri Guru Gobind Singh College Sector-26, Chandigarh, UT, 160019, India
| | - Sandeep Kumar
- Department of Bio& Nanotechnology, Guru Jambheshwar University of Science & Technology, Hisar, Haryana, 125001, India
| | - Neeraj Dilbaghi
- Department of Bio& Nanotechnology, Guru Jambheshwar University of Science & Technology, Hisar, Haryana, 125001, India
| | - Anil K Sharma
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, 133207, Haryana, India.
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Itomi Y, Tanaka T, Matsushita K, Kawamura T, Kojima T, Aso K, Matsumoto-Okano S, Tsukimi Y. Pharmacological evaluation of a novel corticotropin-releasing factor 1 receptor antagonist T-3047928 in stress-induced animal models in a comparison with alosetron. Neurogastroenterol Motil 2020; 32:e13795. [PMID: 31970891 DOI: 10.1111/nmo.13795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/19/2019] [Accepted: 12/13/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND The major symptoms of irritable bowel syndrome (IBS) are changes in bowel habits and abdominal pain. Psychological stress is the major pathophysiological components of IBS. Corticotropin-releasing factor (CRF) is a well-known integrator in response to psychological stress. In this study, a novel CRF1 receptor antagonist T-3047928 was evaluated in stress-induced IBS models of rats to explore its potency for IBS. METHODS Plasma adrenocorticotropic hormone (ACTH) levels after intravenous oCRH challenge were measured as a pharmacodynamic marker. Efficacies of oral T-3047928 were compared with oral alosetron, a 5-HT3 antagonist, on conditioning fear stress (CFS)-induced defecation, restraint stress (RS)-induced acute visceral pain, specific alteration of rhythm in temperature (SART) stress-induced chronic visceral pain, and normal defecation. RESULTS T-3047928 (1-10 mg/kg, p.o.) demonstrated a dose-dependent inhibition on oCRH-induced ACTH secretion. In disease models, T-3047928 suppressed fecal pellet output induced by CFS and improved both acute and chronic visceral hypersensitivity induced by RS and SART stress, respectively. Alosetron was also efficacious in stress-induced defecation and visceral pain models at 1 and 10 mg/kg, respectively. Alosetron, however, also suppressed normal defecation at lower those. On the other hand, T-3047928 did not change normal defecation even at higher dose than those in disease models. CONCLUSION T-3047928 is an orally active CRF1 antagonist that demonstrated potent inhibitory effects in stress-associated IBS models with no effect on normal defecation. Therefore, it is suggested that T-3047928 may have a potency as a novel option for IBS-D therapy with minimal constipation risk.
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Affiliation(s)
- Yasuo Itomi
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Takahiro Tanaka
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Kozo Matsushita
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Toru Kawamura
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Takuto Kojima
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Kazuyoshi Aso
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Shiho Matsumoto-Okano
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Yasuhiro Tsukimi
- Inflammation DDU, Pharmacological Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
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Chow CFW, Che S, Qin HY, Kwan HY, Bian ZX, Wong HLX. From psychology to physicality: how nerve growth factor transduces early life stress into gastrointestinal motility disorders later in life. Cell Cycle 2019; 18:1824-1829. [PMID: 31272268 DOI: 10.1080/15384101.2019.1637203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Environmental stressors in early childhood can have a detrimental impact later in life, manifesting in functional gastrointestinal disorders including irritable bowel syndrome (IBS). The phenomenon is also observed in rodents, where neonatal-maternal separation, a model of early life stress, induces phenotypes similar to IBS; however, the underlying mechanisms remain unelucidated. Our recent study provided a mechanism for the pathogenesis in the gut, demonstrating that increased visceral hyperalgesia resulted from the expansion of the intestinal stem cell compartment leading to increased differentiation and proliferation of serotonin (5-hydroxytryptamine/5-HT)-producing enterochromaffin cells. Moreover, it identified nerve growth factor (NGF) as a key mediator of the pathogenesis; surprisingly, it exerts its effect via cross talk with Wnt/β-catenin signaling. This article addresses the roles of NGF in driving IBS and its potential clinical implications, outstanding questions in how psychological stimuli are transduced into physical phenotypes, as well as future directions of our findings. Abbreviations: 5-HT: 5-hydroxytryptamine/serotonin; BDNF: brain-derived neurotrophic factor; CRF: corticotrophin-releasing factor; EC: enterochromaffin; ENS: enteric nervous system; GI: gastrointestinal; GPCR: G-protein-coupled receptor; IBS (-D): irritable bowel syndrome (diarrhea predominant); LRP5/6: low-density lipoprotein receptor-related protein 5/6; MAPK: mitogen-activated protein kinase; NGF: nerve growth factor; NMS: neonatal-maternal separation; PI3K: phosphoinositode3-kinase; PLCγ: phospholipase c, gamma subtype; TrkA: tropomyosin receptor kinase A.
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Affiliation(s)
- Chi Fung Willis Chow
- a Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR , China
| | - Sijia Che
- a Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR , China
| | - Hong-Yan Qin
- b Department of Pharmacy, First Hospital of Lanzhou University , Lanzhou , China
| | - Hiu Yee Kwan
- a Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR , China
| | - Zhao-Xiang Bian
- a Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR , China
| | - Hoi Leong Xavier Wong
- a Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR , China
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Wong HLX, Qin HY, Tsang SW, Zuo X, Che S, Chow CFW, Li X, Xiao HT, Zhao L, Huang T, Lin CY, Kwan HY, Yang T, Longo FM, Lyu A, Bian ZX. Early life stress disrupts intestinal homeostasis via NGF-TrkA signaling. Nat Commun 2019; 10:1745. [PMID: 30988299 PMCID: PMC6465335 DOI: 10.1038/s41467-019-09744-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/28/2019] [Indexed: 12/29/2022] Open
Abstract
Early childhood is a critical period for development, and early life stress may increase the risk of gastrointestinal diseases including irritable bowel syndrome (IBS). In rodents, neonatal maternal separation (NMS) induces bowel dysfunctions that resemble IBS. However, the underlying mechanisms remain unclear. Here we show that NMS induces expansion of intestinal stem cells (ISCs) and their differentiation toward secretory lineages including enterochromaffin (EC) and Paneth cells, leading to EC hyperplasia, increased serotonin production, and visceral hyperalgesia. This is reversed by inhibition of nerve growth factor (NGF)-mediated tropomyosin receptor kinase A (TrkA) signalling, and treatment with NGF recapitulates the intestinal phenotype of NMS mice in vivo and in mouse intestinal organoids in vitro. Mechanistically, NGF transactivates Wnt/β-catenin signalling. NGF and serotonin are positively correlated in the sera of diarrhea-predominant IBS patients. Together, our findings provide mechanistic insights into early life stress-induced intestinal changes that may translate into treatments for gastrointestinal diseases.
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Affiliation(s)
- Hoi Leong Xavier Wong
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Hong-Yan Qin
- Department of Pharmacy, First Hospital of Lanzhou University, 730000, Lanzhou, China
| | - Siu Wai Tsang
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Xiao Zuo
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Sijia Che
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Chi Fung Willis Chow
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Xi Li
- Department of Gastroenterology, Peking University Shenzhen Hospital, 518035, Shenzhen, China
| | - Hai-Tao Xiao
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, 518060, Shenzhen, China
| | - Ling Zhao
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Tao Huang
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Cheng Yuan Lin
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Hiu Yee Kwan
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Aiping Lyu
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Zhao-Xiang Bian
- Institute of Brain and Gut Axis (IBAG), Centre of Clinical Research for Chinese Medicine, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
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Mine Y, Itakura T, Oku S, Asada R, Shimizu I. DSP-6952, a novel 5-HT 4 receptor partial agonist, inhibits visceral hypersensitivity and ameliorates gastrointestinal dysfunction in experimental animals. Eur J Pharmacol 2018; 826:123-132. [DOI: 10.1016/j.ejphar.2018.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 01/28/2023]
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Qi Q, Zhang Y, Chen F, Zuo X, Li Y. Ramosetron for the treatment of irritable bowel syndrome with diarrhea: a systematic review and meta-analysis of randomized controlled trials. BMC Gastroenterol 2018; 18:5. [PMID: 29310568 PMCID: PMC5759234 DOI: 10.1186/s12876-017-0734-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 12/22/2017] [Indexed: 12/14/2022] Open
Abstract
Background Ramosetron is a potent and selective serotonin type 3 receptor antagonist. This meta-analysis aimed to analyze the efficacy and safety of ramosetron for irritable bowel syndrome with diarrhea (IBS-D). Methods Pubmed, MEDLINE, EMBASE and the Cochrane Library were searched for randomized controlled trials investigating the efficacy and safety of ramosetron for IBS-D. Risk of bias was assessed as described in the Cochrane handbook. A random effects model was used to calculate the effects of ramosetron vs placebo on symptomatic improvements, including relief of overall IBS symptoms, relief of abdominal discomfort/pain, improvement in abnormal bowel habits, and improvement in stool consistency, expressed as pooled relative risks (RRs) with 95% confidence interval (CI). Adverse events data were also summarized with RRs. Results Four randomized controlled trials involving 1623 participants were included. Compared with placebo, ramosetron could lead to relief of overall IBS symptoms (RR 1.70; 95%CI 1.48, 1.95), relief of abdominal discomfort/pain (RR 1.41; 95%CI, 1.24, 1.59), improvement in abnormal bowel habits (RR 1.72; 95%CI, 1.50, 1.98) and improvement in stool consistency (RR 1.71; 95%CI 1.40, 2.08). Ramosetron could lead to relief of overall IBS symptoms in both male and female patients (RR; 95%CI: 1.94; 1.58, 2.38 and 1.49; 1.25, 1.79). The RR (95%CI) for reported adverse events of ramosetron vs placebo was 1.10 (0.97, 1.26) across all studies. No serious adverse events (e.g., ischemic colitis) were reported. The incidences of hard stool and constipation were higher in ramosetron group compared with placebo group (RR; 95%CI: 4.74; 3.00, 7.51 and 2.53; 1.57, 4.10, respectively). Conclusions Ramosetron had beneficial effects to both male and female IBS-D patients. Treatment with ramosetron could cause more hard stool and constipation, without severe adverse events.
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Affiliation(s)
- Qingqing Qi
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong Province, 250012, China
| | - Yan Zhang
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong Province, 250012, China
| | - Feixue Chen
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong Province, 250012, China
| | - Xiuli Zuo
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong Province, 250012, China
| | - Yanqing Li
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong Province, 250012, China.
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Dong Y, Wang Z, Qin Z, Cao J, Chen Y. Role of serotonin in the intestinal mucosal epithelium barrier in weaning mice undergoing stress-induced diarrhea. J Mol Histol 2017; 49:85-97. [PMID: 29260435 DOI: 10.1007/s10735-017-9749-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/05/2017] [Indexed: 12/17/2022]
Abstract
Stress-induced diarrhea is a frequent and challenging threat to humans and domestic animals. Serotonin (5-HT) has been shown to be involved in the pathological process of stress-induced diarrhea. However, the role of 5-HT in stress-induced diarrhea remains unclear. A stress-induced diarrhea model was established in 21-day-old ICR weaning mice through an intragastric administration of 0.25 mL of 0.4 g/mL folium sennae and restraint of the hind legs with adhesive tape for 4 h to determine whether 5-HT regulates the mucosal barrier to cause diarrhea. Mice with decreased levels of 5-HT were pretreated with an intraperitoneal injection of 300 mg/kg p-chlorophenylalanine (PCPA), a 5-HT synthesis inhibitor. After 5 days of treatment, the stress level, body weight and intestinal mucosal morphology indexes were measured. Compared to the controls, the mice with stress-induced diarrhea displayed a stress reaction, with increased corticosterone levels, as well as increased 5-HT-positive cells. However, the mice with stress-induced diarrhea exhibited decreased body weights, villus height to crypt depth ratios (V/C), and Occludin and Claudin1 expression. The PCPA injection reversed these effects in mice with different degrees of stress-induced diarrhea. Based on these findings, inhibition of 5-HT synthesis relieved the stress response and improved the health of the intestinal tract, including both the intestinal absorption capacity, as determined by the villus height and crypt depth, and the mucosal barrier function, as determined by the tight junction proteins of epithelial cell.
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Affiliation(s)
- Yulan Dong
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193, People's Republic of China
| | - Zixu Wang
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193, People's Republic of China
| | - Zhuoming Qin
- Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, 250100, People's Republic of China
| | - Jing Cao
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193, People's Republic of China
| | - Yaoxing Chen
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193, People's Republic of China.
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彭 颖, 李 晓. 倍半萜内酯类治疗肠易激综合征的应用前景. Shijie Huaren Xiaohua Zazhi 2017; 25:1624-1632. [DOI: 10.11569/wcjd.v25.i18.1624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
肠易激综合征(irritable bowel syndrome, IBS)是常见的功能性肠道疾病, 以腹痛或腹部不适、排便习惯异常为特征, 其发病机制尚不明确. 依照罗马Ⅲ标准可将其分为腹泻型、便秘型、混合型和未定型4种亚型. 目前临床治疗原则主要是对症治疗, 迄今尚无特效药物能够有效治疗所有类型IBS. 倍半萜内酯类成分是众多药用植物的生物活性成分, 具有广泛生物学活性, 包括抗肿瘤、抗炎镇痛、抗菌等. 本文就倍半萜内酯类成分可改善IBS症状的相关生物学活性, 及其在IBS治疗中的应用前景进行简要综述.
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Shiotani A, Kusunoki H, Ishii M, Imamura H, Manabe N, Kamada T, Hata J, Merchant J, Haruma K. Pilot study of Biomarkers for predicting effectiveness of ramosetron in diarrhea-predominant irritable bowel syndrome: expression of S100A10 and polymorphisms of TPH1. Neurogastroenterol Motil 2015; 27:82-91. [PMID: 25428414 PMCID: PMC4285583 DOI: 10.1111/nmo.12473] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 10/24/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND Serotonin type 3 receptor (5-HT3 R) antagonists are potentially useful therapeutic agents for diarrhea-predominant irritable bowel syndrome (IBS-D). To identify biomarkers predicting effectiveness of the 5-HT3 R antagonist (ramosetron) in IBS-D. METHODS Irritable bowel syndrome-D Japanese subjects received 2.5 or 5 μg of ramosetron once daily for 4 weeks. Colonic mucosal S100A and tryptophan hydroxylase (TPH) mRNA expression levels were measured before treatment. Genomic DNA was extracted from blood and polymorphisms of TPH1 and TPH2 were analyzed. KEY RESULTS Forty-two patients (27 men and 15 women, mean age 42 years) with IBS-D were included for analysis. Improvement of IBS symptoms was seen in 26 (61.9%). Baseline S100A10 (p = 0.02) and TPH1 (p = 0.02) expression were significantly higher in the ramosetron responders than in the non-responders. The frequencies of the TPH1 rs4537731G allele in linkage disequilibrium with the TPH1 rs7130929 T allele (11.5% vs 50%, p = 0.003; OR: 12; 95% CI: 2.1-69) along with TPH1 rs211105 C allele (3.8% vs 43.8%, p = 0.0003; OR: 19; 95% CI: 2.1-181) were significantly lower in the responders than in the non-responders. The mean scores of diarrhea at baseline were significantly higher (5.2 vs 3.7, p = 0.005) in patients with TPH1 rs211105 T/T than those with the G allele. CONCLUSIONS & INFERENCES TPH1 gene polymorphisms and S100A10 expression, which correlate with 5-HT signaling were associated with ramosetron effectiveness in IBS-D, and may possibly lead to prospective identification of the resistance to treatment.
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Affiliation(s)
- Akiko Shiotani
- Department of Internal Medicine, Kawasaki Medical School, Okayama, Japan
| | - Hiroaki Kusunoki
- Department of Comprehensive Medicine, Kawasaki Medical School, Okayama, Japan
| | - Mnabu Ishii
- Department of Internal Medicine, Kawasaki Medical School, Okayama, Japan
| | - Hiroshi Imamura
- Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Okayama, Japan
| | - Noriaki Manabe
- Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Okayama, Japan
| | - Tomoari Kamada
- Department of Internal Medicine, Kawasaki Medical School, Okayama, Japan
| | - Jiro Hata
- Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Okayama, Japan
| | - Juanita Merchant
- Department of Internal Medicine and Molecular and Integrative Physiology University of Michigan, Ann Arbor, USA
| | - Ken Haruma
- Department of Internal Medicine, Kawasaki Medical School, Okayama, Japan
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12
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Farajian Mashhadi F, Naylor RJ, Javid FA. The Effects of Serotonin Receptor Antagonists on Contraction and Relaxation Responses Induced by Electrical Stimulation in the Rat Small Intestine. ACTA ACUST UNITED AC 2014. [DOI: 10.17795/gct-18311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Page C, Humphrey P. Sir David Jack: an extraordinary drug discoverer and developer. Br J Clin Pharmacol 2013; 75:1213-8. [PMID: 22994263 DOI: 10.1111/j.1365-2125.2012.04467.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Clive Page
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, UK
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14
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Moore NA, Sargent BJ, Manning DD, Guzzo PR. Partial agonism of 5-HT3 receptors: a novel approach to the symptomatic treatment of IBS-D. ACS Chem Neurosci 2013; 4:43-7. [PMID: 23342199 DOI: 10.1021/cn300166c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/10/2012] [Indexed: 12/19/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by abdominal pain, discomfort, and altered bowel habits, which have a significant impact on quality of life for approximately 10-20% of the population. IBS can be divided into three main types IBS-D (diarrhea predominant), IBS-C (constipation predominant), and mixed or alternating IBS. 5-HT(3) receptor antagonism has proved to be an efficacious treatment option for IBS-D. For example, alosetron displays efficacy in the treatment of multiple symptoms, including abdominal pain, discomfort, urgency, stool frequency and consistency. However, significant constipation occurred in approximately 25% of patients, leading to withdrawal of up to 10% of patients in clinical trials. Targeting compounds with partial agonist activity at the 5-HT(3) receptor represents a mechanistic departure from the classic 5-HT(3) receptor antagonist approach and should result in agents that are applicable to a broader array of IBS patient populations. Attenuation of the activity of the ion channel without completely abolishing its function may control or normalize bowel function without leading to a total block associated with severe constipation. We have identified a new class of selective, orally active 5-HT(3) receptor ligands with high 5-HT(3) receptor affinity and low partial agonist activity currently in preclinical development that should offer a significant advantage over existing therapies.
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Affiliation(s)
- Nicholas A. Moore
- Albany Molecular Research Inc. (AMRI), 26 Corporate Circle, Albany, New York 12212, United States
| | - Bruce J. Sargent
- Albany Molecular Research Inc. (AMRI), 26 Corporate Circle, Albany, New York 12212, United States
| | - David D. Manning
- Albany Molecular Research Inc. (AMRI), 26 Corporate Circle, Albany, New York 12212, United States
| | - Peter R. Guzzo
- Albany Molecular Research Inc. (AMRI), 26 Corporate Circle, Albany, New York 12212, United States
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15
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Henderson WA, Shankar R, Taylor TJ, Del Valle-Pinero AY, Kleiner DE, Kim KH, Youssef NN. Inverse relationship of interleukin-6 and mast cells in children with inflammatory and non-inflammatory abdominal pain phenotypes. World J Gastrointest Pathophysiol 2012; 3:102-8. [PMID: 23516176 PMCID: PMC3602438 DOI: 10.4291/wjgp.v3.i6.102] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 11/16/2012] [Accepted: 12/06/2012] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate interleukin-6 (IL-6), mast cells, enterochromaffin cells, 5-hydroxytryptamine, and substance P in the gastrointestinal mucosa of children with abdominal pain. METHODS Formalin-fixed paraffin-embedded gastrointestinal biopsy blocks from patients (n = 48) with non-inflammatory bowel disease (irritable bowel syndrome and functional abdominal pain) and inflammatory bowel disease were sectioned and stained for IL-6, mast cells, enterochromaffin cells, 5-hydroxytryptamine, and substance P. All children had chronic abdominal pain as part of their presenting symptoms. Biopsy phenotype was confirmed by a pathologist, blinded to patient information. Descriptive statistics, chi-square, and independent sample t tests were used to compare differences between the inflammatory and non-inflammatory groups. RESULTS The cohort (n = 48), mean age 11.9 years (SD = 2.9), 54.2% females, 90% Caucasian, was comprised of a non-inflammatory (n = 26) and an inflammatory (n = 22) phenotype. There was a significant negative correlation between substance P expression and mast cell count (P = 0.05, r = -0.373). Substance P was found to be expressed more often in female patient biopsies and more intensely in the upper gastrointestinal mucosa as compared to the lower mucosa. There were significantly increased gastrointestinal mucosal immunoreactivity to IL-6 (P = 0.004) in the inflammatory phenotype compared to non-inflammatory. Additionally, we found significantly increased mast cells (P = 0.049) in the mucosa of the non-inflammatory phenotype compared to the inflammatory group. This difference was particularly noted in the lower colon biopsies. CONCLUSION The findings of this study yield preliminary evidence in identifying biomarkers of undiagnosed abdominal pain in children and may suggest candidate genes for future evaluation.
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16
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MIFTAHOF R. NUMERICAL SIMULATION OF THE ROLE OF CO-TRANSMISSION BY ACETYLCHOLINE AND SEROTONIN ON MOTILITY OF THE GUT. J MECH MED BIOL 2011. [DOI: 10.1142/s0219519406002035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Electrophysiological mechanisms of co-transmission by serotonin (5-HT) and acetylcholine (ACh), co-expression of their receptor types, i.e., 5-HT type 3 and 4, nicotinic cholinerginc (nACh) and muscarinic cholinergic (μACh), and effects of selective and non-selective 5-HT3 and 5-HT4 receptor agonists/antagonists, on electromechanical activity of the gut were studied numerically. Two series of numerical experiments were performed. First, the dynamics of the generation and propagation of electrical signals interconnected with the primary sensory (AH) neurons, motor (S) neurons and smooth muscle cells were studied in a one-dimensional model. Simulations showed that stimulation of the 5-HT3 receptors reduced the threshold of activation of the mechanoreceptors by 17.6%. Conjoint excitation of the 5-HT3 and 5-HT4 receptors by endogenous serotonin converted the regular firing pattern of electrical discharges of the AH and S neurons to a beating mode. Activation confined to 5-HT3 receptors, located on the somas of the adjacent AH and S type neurons, could not sustain normal signal transduction between them. It required ACh as a co-transmitter and co-activation of the nACh receptors. Application of selective 5-HT3 receptor antagonists inhibited dose-dependently the production of action potentials at the level of mechanoreceptors and the soma of the primary sensory neuron and increased the threshold activation of the mechanoreceptors. Normal mechanical contractile activity depended on co-stimulation of the 5-HT4 and μACh receptors on the membrane of smooth muscle cells. In the second series of simulations, which involved a spatio-temporal model of the functional unit, effects of co-transmission by ACh and 5-HT on the electromechanical response in a segment of the gut were analyzed. Results indicated that propagation of the wave of excitation between the AH and S neurons within the myenteric nervous plexus in the presence of 5-HT3 receptor antagonists was supported by co-release of ACh. Co-stimulation of 5-HT3, nACh and μACh receptors impaired propulsive activity of the gut. The bolus showed uncoordinated movements. In an ACh-free environment Lotronex (GlaxoSmithKline), a 5-HT3 receptor antagonist, significantly increased the transit time of the pellet along the gut. In the presence of ACh, Lotronex produced intensive tonic-type contractions in the longitudinal and circular smooth muscle layers and eliminated propulsive activity. The 5HT4 receptor agonist, Zelnorm (Novartis), preserved the reciprocal electromechanical relationships between the longitudinal and circular smooth muscle layers. The drug changed the normal propulsive pattern of activity to an expulsive (non-mixing) type. Treatment of the gut with selective 5HT4 receptor antagonists increased the transit time by disrupting the migrating myoelectrical complex. Cisapride (Janssen), a mixed 5HT3 and 5HT4 receptor agonist, increased excitability of the AH and S neurons and the frequency of slow waves. Longitudinal and circular smooth muscle syncytia responded with the generation of long-lasting tonic contractions, resulting in a "squeezing" type of pellet movement. Comparison of the theoretical results obtained on one-dimensional and spatio-temporal models to in vivo and in vitro experimental data indicated satisfactory qualitative, and where available, quantitative agreement.
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Affiliation(s)
- R. MIFTAHOF
- Division of Applied Mathematics, KAIST, Daejeon, Republic of Korea
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17
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Kapeller J, Möller D, Lasitschka F, Autschbach F, Hovius R, Rappold G, Brüss M, Gershon MD, Niesler B. Serotonin receptor diversity in the human colon: Expression of serotonin type 3 receptor subunits 5-HT3C, 5-HT3D, and 5-HT3E. J Comp Neurol 2011; 519:420-32. [PMID: 21192076 DOI: 10.1002/cne.22525] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Since the first description of 5-HT₃ receptors more than 50 years ago, there has been speculation about the molecular basis of their receptor heterogeneity. We have cloned the genes encoding novel 5-HT3 subunits 5-HT3C, 5-HT3D, and 5-HT3E and have shown that these subunits are able to form functional heteromeric receptors when coexpressed with the 5-HT3A subunit. However, whether these subunits are actually expressed in human tissue remained to be confirmed. In the current study, we performed immunocytochemistry to locate the 5-HT3A as well as the 5-HT3C, 5-HT3D, and 5-HT3E subunits within the human colon. Western blot analysis was used to confirm subunit expression, and RT-PCR was employed to detect transcripts encoding 5-HT₃ receptor subunits in microdissected tissue samples. This investigation revealed, for the first time, that 5-HT3C, 5-HT3D, and 5-HT3E subunits are coexpressed with 5-HT3A in cell bodies of myenteric neurons. Furthermore, 5-HT3A and 5-HT3D were found to be expressed in submucosal plexus of the human large intestine. These data provide a strong basis for future studies of the roles that specific 5-HT₃ receptor subtypes play in the function of the enteric and central nervous systems and the contribution that specific 5-HT₃ receptors make to the pathophysiology of gastrointestinal disorders such as irritable bowel syndrome and dyspepsia.
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Affiliation(s)
- Johannes Kapeller
- Department of Human Molecular Genetics, University of Heidelberg, Germany
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18
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Acosta RD, Cash BD. Existing and emerging therapies for irritable bowel syndrome. Expert Opin Emerg Drugs 2011; 16:389-402. [PMID: 21438740 DOI: 10.1517/14728214.2011.566214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Irritable bowel syndrome is a common disorder that is associated with a significant impact on both affected individuals and society. While the pathophysiology of irritable bowel syndrome remains unknown, knowledge regarding the normal and abnormal functions of the gut and its complex interaction with the body's nervous systems continues to shed light on the multifactorial origins of irritable bowel syndrome symptoms. This article provides an overview of the current knowledge of the therapeutic approaches to irritable bowel syndrome. AREAS COVERED A search of the online bibliographic databases MEDLINE and EMBASE was performed in order to identify all relevant articles published between 1980 and 2010. The search was enhanced with the use of a medical librarian. Bibliographies from potentially relevant articles were manually searched. EXPERT OPINION The therapeutic options for irritable bowel syndrome are rapidly evolving beyond traditional symptom-based therapies, such as fiber, antispasmodics, antidiarrheals and laxatives, and are moving toward agents with organ-specific receptor selectivity directed, in many cases, at specific gastrointestinal functions.
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Affiliation(s)
- Ruben D Acosta
- National Naval Medical Center and Walter Reed Army Medical Center, Division of Gastroenterology, 8901 Wisconsin Avenue, Bethesda, MD 20889-5000, USA
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19
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Ghaith O, El-Halabi M, Hashash JG, Sharara AI. Investigational agents for the irritable bowel syndrome. Expert Opin Investig Drugs 2011; 19:1161-78. [PMID: 20836617 DOI: 10.1517/13543784.2010.513380] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IMPORTANCE OF THE FIELD Irritable bowel syndrome (IBS) is a common disorder with significant health and economic consequences. The etiology of IBS is complex and appears to be multifactorial. Traditional IBS therapies have been directed primarily at the relief of individual symptoms but have been largely disappointing. This has triggered the search for newer treatment strategies with improved patient outcomes. AREAS COVERED IN THIS REVIEW Enhanced knowledge about the putative pathophysiology of IBS has allowed the identification of new mechanistic targets for treatment. Our aim is to review emerging and promising drugs in the treatment of IBS based on disease pathophysiology. Data were extracted using Medline and PubMed search engines until January 2010. Abstracts were identified through 'Web of Science' and abstract supplements of major gastrointestinal scientific meetings. Drugs were classified according to mechanism of action and those with efficacy in trials involving human subjects examined. WHAT THE READER WILL GAIN Additional insight into the pathophysiology as well as current and prospective treatments of IBS. TAKE HOME MESSAGE A multitude of putative drug targets have been identified and some novel treatments have progressed through to human clinical trials, but very few will be approved for the market in the near future. Moreover, and in keeping with the complex and multifactorial nature of this syndrome, it is unlikely that there will be one dominant and universally effective form of therapy for all IBS patients.
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Affiliation(s)
- Ola Ghaith
- Division of Gastroenterology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
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20
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21
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Walstab J, Rappold G, Niesler B. 5-HT(3) receptors: role in disease and target of drugs. Pharmacol Ther 2010; 128:146-69. [PMID: 20621123 DOI: 10.1016/j.pharmthera.2010.07.001] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 06/21/2010] [Indexed: 12/19/2022]
Abstract
Serotonin type 3 (5-HT(3)) receptors are pentameric ion channels belonging to the superfamily of Cys-loop receptors. Receptor activation either leads to fast excitatory responses or modulation of neurotransmitter release depending on their neuronal localisation. 5-HT(3) receptors are known to be expressed in the central nervous system in regions involved in the vomiting reflex, processing of pain, the reward system, cognition and anxiety control. In the periphery they are present on a variety of neurons and immune cells. 5-HT(3) receptors are known to be involved in emesis, pain disorders, drug addiction, psychiatric and GI disorders. Progress in molecular genetics gives direction to personalised medical strategies for treating complex diseases such as psychiatric and functional GI disorders and unravelling individual drug responses in pharmacogenetic approaches. Here we discuss the molecular basis of 5-HT(3) receptor diversity at the DNA and protein level, of which our knowledge has greatly extended in the last decade. We also evaluate their role in health and disease and describe specific case-control studies addressing the involvement of polymorphisms of 5-HT3 subunit genes in complex disorders and responses to drugs. Furthermore, we focus on the actual state of the pharmacological knowledge concerning not only classical 5-HT(3) antagonists--the setrons--but also compounds of various substance classes targeting 5-HT(3) receptors such as anaesthetics, opioids, cannabinoids, steroids, antidepressants and antipsychotics as well as natural compounds derived from plants. This shall point to alternative treatment options modulating the 5-HT(3) receptor system and open new possibilities for drug development in the future.
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Affiliation(s)
- Jutta Walstab
- Department of Human Molecular Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
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Matsueda K, Harasawa S, Hongo M, Hiwatashi N, Sasaki D. A randomized, double-blind, placebo-controlled clinical trial of the effectiveness of the novel serotonin type 3 receptor antagonist ramosetron in both male and female Japanese patients with diarrhea-predominant irritable bowel syndrome. Scand J Gastroenterol 2009; 43:1202-11. [PMID: 18618371 DOI: 10.1080/00365520802240255] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Irritable bowel syndrome is characterized by abdominal discomfort and/or pain associated with altered bowel habits. The neurotransmitter serotonin and serotonin type 3 receptors that are extensively distributed on enteric neurons in the human gastrointestinal tract play a role in increasing the sensation of pain and affecting bowel habits in patients with irritable bowel syndrome. The aim of this study was to evaluate the efficacy and safety of the serotonin type 3 receptor antagonist ramosetron hydrochloride in Japanese patients with diarrhea-predominant irritable bowel syndrome. MATERIAL AND METHODS In a double-blind, placebo-controlled, parallel group-comparative study with a 1-week run-in period, 539 patients with diarrhea-predominant irritable bowel syndrome meeting the Rome II diagnostic criteria received either 5 microg ramosetron hydrochloride (n=270) or placebo (n=269) once daily for 12 weeks. RESULTS Forty-seven percent of ramosetron hydrochloride-treated patients were monthly responders in the primary end-point, "Patient-reported global assessment of relief of irritable bowel syndrome symptoms", compared with 27% for placebos (p<0.001). The most frequently reported adverse event in the ramosetron hydrochloride-treated group compared with the placebo group was hard stool. CONCLUSIONS Ramosetron hydrochloride 5 microg once daily is effective and well tolerated in the treatment of abdominal pain, discomfort and bowel habits in patients with diarrhea-predominant irritable bowel syndrome.
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Affiliation(s)
- Kei Matsueda
- International Medical Center of Japan Kohnodai Hospital, Kohnodai, Ichikawa, Chiba 272-8516, Japan.
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23
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Serotonin pharmacology in the gastrointestinal tract: a review. Naunyn Schmiedebergs Arch Pharmacol 2008; 377:181-203. [PMID: 18398601 DOI: 10.1007/s00210-008-0276-9] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Accepted: 02/15/2008] [Indexed: 12/17/2022]
Abstract
Serotonin (5-hydroxytryptamine or 5-HT) plays a critical physiological role in the regulation of gastrointestinal (GI) function. 5-HT dysfunction may also be involved in the pathophysiology of a number of functional GI disorders, such as chronic constipation, irritable bowel syndrome and functional dyspepsia. This article describes the role of 5-HT in the enteric nervous system (ENS) of the mammalian GI tract and the receptors with which it interacts. Existing serotonergic therapies that have proven effective in the treatment of GI functional disorders and the potential of drugs currently in development are also highlighted. Advances in our understanding of the physiological and pathophysiological roles of 5-HT in the ENS and the identification of selective receptor ligands bodes well for the future development of more efficacious therapies for patients with functional GI disorders.
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Stacher G. Cilansetron in the treatment of diarrhea-predominant irritable bowel syndrome? Expert Rev Gastroenterol Hepatol 2007; 1:15-27. [PMID: 19072430 DOI: 10.1586/17474124.1.1.15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Information on the 5-hydroxytryptamine type 3 receptor antagonist cilansetron is scarce and most studies have only been published in abstract form. Results from preclinical and two dose-finding studies have suggested that cilansetron could be effective in the treatment of patients with diarrhea-predominant irritable bowel syndrome. Two large efficacy and safety trials extending over 3 and 6 months revealed a superiority of cilansetron 2 mg orally three-times daily over placebo reflected by numbers needed to treat of 4.8 and 5.6, respectively, for the parameter proportion of patients reporting adequate symptom relief. Dose-ranging studies showed no dose-response relationship. Cilansetron tended to induce constipation but, apart from transient ischemic colitis in four out of 1484 cases, no serious adverse effects were observed. Further trials are underway to fully determine the role of cilansetron in the treatment of diarrhea-predominant irritable bowel syndrome.
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Affiliation(s)
- Georg Stacher
- Professor, Medical University of Vienna, Psychophysiology Unit, Department of Surgery, A-1090 Wien, Austria.
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25
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Holbrook JD, Sanseau P. Drug discovery and computational evolutionary analysis. Drug Discov Today 2007; 12:826-32. [PMID: 17933683 DOI: 10.1016/j.drudis.2007.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 08/31/2007] [Accepted: 08/31/2007] [Indexed: 01/26/2023]
Abstract
Drug discovery remains a difficult business with a very high level of attrition. Many steps in this long process use data generated from various species. One key challenge is to successfully translate the pre-clinical findings of target validation and safety studies in animal models to diverse human beings in the clinic. Advanced computational evolutionary analysis techniques combined with the increasing availability of sequence information enable the application of systematic evolutionary approaches to targets and pathways of interest to drug discovery. These analyses have the potential to increase our understanding of experimental differences observed between species.
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Affiliation(s)
- Joanna D Holbrook
- GlaxoSmithKline, Molecular Discovery Research, Bioinformatics Analysis, Stevenage SG1 2NY, United Kingdom
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26
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Miftahof R, Akhmadeev N. Dynamics of intestinal propulsion. J Theor Biol 2007; 246:377-93. [PMID: 17306304 DOI: 10.1016/j.jtbi.2007.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 01/06/2007] [Accepted: 01/08/2007] [Indexed: 01/12/2023]
Abstract
A biomechanical model and mathematical formulation of the problem of propulsion of a solid non-deformable pellet by an isolated segment of the gut are presented. The organ is modeled as a soft orthotropic cylindrical biological shell. Its wall is reinforced by transversely isotropic muscle fibers of orthogonal type of weaving embedded in a connective tissue stroma. The mechanical properties of the wall are assumed to be nonlinear, deformations are finite. The longitudinal smooth muscle syncitium possesses anisotropic and the circular muscle syncytium has anisotropic electrical properties. Their electromechanical activity is under control of a pacemaker, which is represented by interstitial cells of Cajal. The model describes the dynamics of the generation and propagation of mechanical waves of contraction-relaxation along the surface of the bioshell and propulsion of the pellet. The governing system of equations was solved numerically. The combined finite-difference and finite-element method was used. The results demonstrate that pendular movements alone provide an aboral transit, without mixing though, of the bolus. Non-propagating segmental contractions show small amplitude librations of the pellet without its visible propulsion. Only the coordinated activity of both smooth muscle layers in a form of the peristaltic reflex provides physiologically significant simultaneous propulsion and mixing of the intraluminal content (pellet).
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Affiliation(s)
- R Miftahof
- Division of Applied Mathematics, Korea Advance Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon, S. Korea.
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27
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Millan MJ. Multi-target strategies for the improved treatment of depressive states: Conceptual foundations and neuronal substrates, drug discovery and therapeutic application. Pharmacol Ther 2006; 110:135-370. [PMID: 16522330 DOI: 10.1016/j.pharmthera.2005.11.006] [Citation(s) in RCA: 419] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 11/28/2005] [Indexed: 12/20/2022]
Abstract
Major depression is a debilitating and recurrent disorder with a substantial lifetime risk and a high social cost. Depressed patients generally display co-morbid symptoms, and depression frequently accompanies other serious disorders. Currently available drugs display limited efficacy and a pronounced delay to onset of action, and all provoke distressing side effects. Cloning of the human genome has fuelled expectations that symptomatic treatment may soon become more rapid and effective, and that depressive states may ultimately be "prevented" or "cured". In pursuing these objectives, in particular for genome-derived, non-monoaminergic targets, "specificity" of drug actions is often emphasized. That is, priority is afforded to agents that interact exclusively with a single site hypothesized as critically involved in the pathogenesis and/or control of depression. Certain highly selective drugs may prove effective, and they remain indispensable in the experimental (and clinical) evaluation of the significance of novel mechanisms. However, by analogy to other multifactorial disorders, "multi-target" agents may be better adapted to the improved treatment of depressive states. Support for this contention is garnered from a broad palette of observations, ranging from mechanisms of action of adjunctive drug combinations and electroconvulsive therapy to "network theory" analysis of the etiology and management of depressive states. The review also outlines opportunities to be exploited, and challenges to be addressed, in the discovery and characterization of drugs recognizing multiple targets. Finally, a diversity of multi-target strategies is proposed for the more efficacious and rapid control of core and co-morbid symptoms of depression, together with improved tolerance relative to currently available agents.
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Affiliation(s)
- Mark J Millan
- Institut de Recherches Servier, Centre de Recherches de Croissy, Psychopharmacology Department, 125, Chemin de Ronde, 78290-Croissy/Seine, France.
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Miftahof R, Fedotov E. Intestinal propulsion of a solid non-deformable bolus. J Theor Biol 2005; 235:57-70. [PMID: 15833313 DOI: 10.1016/j.jtbi.2004.12.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2004] [Revised: 12/14/2004] [Accepted: 12/15/2004] [Indexed: 11/19/2022]
Abstract
A mathematical model of a segment of the gut with an enclosed pellet is constructed. The gut is represented as a thin deformable soft biological shell with the pellet modeled as a non-deformable solid. Mechanical properties of the gut wall were represented as longitudinal and circular smooth muscle layers embedded in stroma that satisfies the general type of nonlinear orthotropy. Deformations of the wall are finite. Bolus propulsion is numerically simulated by generation and propagation of an electromechanical wave along the syncytia. Pharmacological manipulation is applied to model 5-HT type 3 antagonist (Lotronex, GlaxoSmithKline) and 5-HT type 4 agonist (Zelnorm, Novartis, AB) drugs on the dynamics of bolus progression. The results lead to new quantitative insights into the complex spatio-temporal patterns of gastrointestinal transit. It is demonstrated that the reciprocal relationship in contraction of the longitudinal and circular smooth muscle syncytia is necessary to provide the "mixing" type of movements during the preparatory phase of propulsion. Strong simultaneous contractions of the both smooth muscle layers are required to expel the "mixed" pellet from the segment. The model is implemented as an interactive software system, Gut Discovery(www.aincompany.com), and accurately predicts the effects of drugs on gut motility.
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Affiliation(s)
- R Miftahof
- Ain Company LLC, Coralville, IA 52241, USA.
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Abstract
The bowel exhibits reflexes in the absence of CNS input. To do so, epithelial sensory transducers, such as enterochromaffin (EC) cells, activate the mucosal processes of intrinsic (IPANs) and extrinsic primary afferent (sensory) neurons. EC cells secrete serotonin (5-HT) in response to mucosal stimuli. Submucosal IPANs, which secrete acetylcholine and calcitonin gene-related peptide, initiate peristaltic and secretory reflexes and are activated via "5-HT1P" receptors. Release of neurotransmitters is enhanced by 5-HT4 receptors, which are presynaptic and strengthen neurotransmission in prokinetic pathways. 5-HT3 receptors mediate signaling to the CNS and thus ameliorate cancer chemotherapy-associated nausea and the visceral hypersensitivity of diarrhea-predominant irritable bowel syndrome (IBS-D); however, because 5-HT3 receptors also mediate fast ENS neurotransmission and activate myenteric IPANs, they may be constipating. 5-HT4 agonists are prokinetic and relieve discomfort and constipation in IBS-C and chronic constipation. 5-HT4 agonists do not initiate peristaltic and secretory reflexes but strengthen pathways that are naturally activated. Serotonergic signaling in the mucosa and the ENS is terminated by a transmembrane 5-HT transporter, SERT. Mucosal SERT and tryptophan hydroxylase-1 expression are decreased in experimental inflammation, IBS-C, IBS-D, and ulcerative colitis. Potentiation of 5-HT due to the SERT decrease could account for the discomfort and diarrhea of IBS-D, while receptor desensitization may cause constipation. Similar symptoms are seen in transgenic mice that lack SERT. The loss of mucosal SERT may thus contribute to IBS pathogenesis.
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Affiliation(s)
- Michael D Gershon
- Department of Anatomy and Cell Biology, Columbia University, P and S, New York, NY 10032, USA.
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30
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Smith RP. Gastrointestinal disease in adolescents. J Pediatr Adolesc Gynecol 2005; 18:3-8. [PMID: 15749578 DOI: 10.1016/j.jpag.2004.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Roger P Smith
- Department of Obstetrics and Gynecology, University of Missouri-Kansas City, Truman Medical Center, 2301 Holmes St., Kansas City, Missouri 64108, USA.
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31
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Reist M, Pfaffl MW, Morel C, Meylan M, Hirsbrunner G, Blum JW, Steiner A. Quantitative mRNA analysis of eight bovine 5-HT receptor subtypes in brain, abomasum, and intestine by real-time RT-PCR. J Recept Signal Transduct Res 2004; 23:271-87. [PMID: 14753293 DOI: 10.1081/rrs-120026971] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Serotoninergic pathways are involved in economically important bovine gastrointestinal (GI) motility disorders such as displaced abomasum and cecal dilatation/dislocation. The existing research tools to investigate the role of serotoninergic pathways in such disorders in ruminants comprise functional pharmacological methods, e.g., in vitro contractility studies in tissue baths, and electromyographical recordings in vivo. However, no tools for quantification of bovine serotonin receptor [5-hydroxytryptamine receptor (5-HTR)] expression were available so far. This study aimed to develop real-time RT-PCR assays for quantitative mRNA analysis of bovine 5-HTR subtypes. Because the bovine 5-HTR coding sequences (CDSs) were completely unknown, multiple species (human, mouse, and rat) alignment of complete CDS was used for primer design in highly homologous regions. LightCycler real-time RT-PCR assays (partial CDS) for the following bovine 5-HTR subtypes were developed and validated: 5-HTR1A, 5-HTR1B, 5-HTR1D, 5-HTR1F, 5-HTR2A, 5-HTR2B, 5-HTR2C, and 5-HTR4. Intra- and inter-assay coefficients of variation (CV) for the eight established assays were small, ranging from 0.49% to 2.46%. As a first physiological application, 5-HTR mRNA expression levels were measured in brain, abomasum, and intestine of 10 healthy, lactating dairy cows. The 5-HTR expression was quantified by normalization to the housekeeping gene glyceraldehyde-phosphate-dehydrogenase (GAPDH). The 5-HTR subtype expression levels ranged from 0.001% (5-HTR2C in intestine) to 1% 5-HTR/GAPDH (5-HTR1B and 5-HTR4 in intestine). There were high variations of 5-HTR subtype mRNA expression within tissues across receptor subtypes and within receptor subtypes across tissues. In conclusion, accurate real-time RT-PCR assays for quantitative analysis of bovine 5-HTR subtype gene expression were developed and validated.
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Affiliation(s)
- Martin Reist
- Department of Clinical Veterinary Medicine, Clinic for Ruminants, Faculty of Veterinary Medicine, University of Berne, Berne, Switzerland
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32
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Mori T, Kawano KI, Shishikura T. 5-HT3-Receptor Antagonist Inhibits Visceral Pain Differently in Chemical and Mechanical Stimuli in Rats. J Pharmacol Sci 2004; 94:73-6. [PMID: 14745121 DOI: 10.1254/jphs.94.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The present study was designed to compare the effects of a selective 5-HT(3)-receptor antagonist, alosetron, on the glycerol-and colorectal distention (CRD)-induced visceral nociception as measured by changes in EMG of the external oblique muscle in conscious rats. Both glycerol and CRD evoked the EMG response, and these amplified EMG were attenuated by morphine, indicating that these responses might reflect visceral nociceptive responses. In the present study, we showed that alosetron significantly attenuated the glycerol-induced visceral pain, but not that of CRD. These results suggest that the mechanism of glycerol-induced visceral nociception are apparently different from that of CRD.
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Affiliation(s)
- Tomohisa Mori
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Yokohama, Japan
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33
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Abstract
Irritable bowel syndrome (IBS) is one of the most common diagnoses made in the primary care setting and is responsible for up to 40% of referrals to gastroenterologists. Approximately 70% of persons who meet the diagnostic criteria for IBS do not seek health care, and the remaining account for 12% of visits to primary care providers. IBS is a functional bowel disordered comprising abdominal pain associated with defecation or a change in bowel habit with features of disordered defecation and distension in the absence of any demonstrable abnormality. The diagnosis is based on clinical findings and the exclusion of other disorders. New pharmaceutical agents are available to treat the underlying disorder; however, the treatment of IBS still involves a comprehensive, multicomponent approach that includes medical management of dominant symptoms, dietary modifications, and, possibly, psychotherapy.
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Affiliation(s)
- Atif Zaman
- Division of Gastroenterology, Oregon Health & Science University, Portland, Oregon, USA
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Niesler B, Frank B, Kapeller J, Rappold GA. Cloning, physical mapping and expression analysis of the human 5-HT3 serotonin receptor-like genes HTR3C, HTR3D and HTR3E. Gene 2003; 310:101-11. [PMID: 12801637 DOI: 10.1016/s0378-1119(03)00503-1] [Citation(s) in RCA: 198] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
For more than 50 years the serotonin system has been the subject of intense research. This has provided an exciting insight and led to the discovery of multiple drugs targeting serotonin receptors, metabolising enzymes and re-uptake sites. During the past few years researchers focussed especially on elucidating the complexity of different physiological actions in the serotonergic network. We have identified two novel human serotonin 5-hydroxytryptamine type 3 receptor-like genes, HTR3D and HTR3E, by performing homology searches using the public human sequence databases and subsequently cloned the full length cDNAs by 5' and 3' rapid amplification of complementary DNA ends. Mapping of HTR3D and HTR3E by hybridisation, polymerase chain reaction and fluorescence in situ hybridisation revealed that both genes together with HTR3C are clustered in a subinterval of less than 100 kb on chromosome 3q27. Comparative expression analysis of all HTR3 genes, namely HTR3A, B, C, D and E showed HTR3D expression to be restricted to kidney, colon and liver and HTR3E expression to colon and intestine, whereas all other genes are widely expressed in many tissues including brain.
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Affiliation(s)
- Beate Niesler
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
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Simrén M, Simms L, D'Souza D, Abrahamsson H, Björnsson ES. Lipid-induced colonic hypersensitivity in irritable bowel syndrome: the role of 5-HT3 receptors. Aliment Pharmacol Ther 2003; 17:279-87. [PMID: 12534414 DOI: 10.1046/j.1365-2036.2003.01399.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Irritable bowel syndrome patients demonstrate colonic hypersensitivity after duodenal lipid infusion. AIM To investigate the role of 5-hydroxytryptamine-3 (5-HT3) receptors in this sensory component of the gastrocolonic response in irritable bowel syndrome. METHODS Fifteen female patients with diarrhoea-predominant irritable bowel syndrome completed a trial with the 5-HT3 receptor antagonist alosetron (1 mg b.d.) or placebo (b.d.) over 15 days, followed by the alternative treatment. Each treatment period was followed by a colonic distension trial before and after duodenal lipids. Changes in colonic thresholds, tone and compliance and viscerosomatic referral pattern after lipids were compared between treatments. RESULTS With placebo, the colonic thresholds after lipids were significantly reduced for all studied sensations, whereas, with alosetron, the thresholds were significantly reduced only for first sensation and discomfort, but not for gas and pain. The reductions in thresholds did not differ significantly between treatments, but the pain threshold after alosetron tended to be less reduced compared with placebo (P = 0.10). The effects of lipids on tone, compliance and viscerosomatic referral pattern were unaffected by alosetron relative to placebo. CONCLUSIONS 5-HT3 receptor antagonism reduces the lipid-induced colonic hypersensitivity in irritable bowel syndrome. However, 5-HT3 receptors do not seem to be the principal mediator, but may be a cofactor for the exaggerated sensory component of the gastrocolonic response in irritable bowel syndrome.
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Affiliation(s)
- M Simrén
- Department of Internal Medicine, Sahlgrenska University Hospital, Göteburg, Sweden.
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36
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Olden K, DeGarmo RG, Jhingran P, Bagby B, Decker C, Markowitz M, Carter E, Bobbitt W, Dahdul A, DeCastro E, Gringeri L, Johanson J, Levinson L, Mula G, Poleynard G, Stoltz RR, Truesdale R, Young D. Patient satisfaction with alosetron for the treatment of women with diarrhea-predominant irritable bowel syndrome. Am J Gastroenterol 2002; 97:3139-46. [PMID: 12492201 DOI: 10.1111/j.1572-0241.2002.07111.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The efficacy and tolerability of alosetron in women with diarrhea-predominant irritable bowel syndrome (IBS) have been established in double-blind, placebo-controlled trials. However, the degree to which alosetron fulfills the needs of those suffering from IBS has not been thoroughly examined from the patient's perspective. This randomized, double-blind, placebo-controlled study conducted in women with diarrhea-predominant IBS evaluated patients' overall satisfaction with treatment as well as their satisfaction with respect to several specific medication attributes. METHODS Patients randomized to receive either alosetron 1 mg b.id. (n = 532) or placebo (n = 269) were administered a questionnaire on which they rated on 7-point Likert scales their prestudy IBS treatment (at the screening visit) or study medication (on wk 12 or final study visit) with respect to overall satisfaction and 11 specific medication attributes. RESULTS Whereas approximately 10% of patients were satisfied or very satisfied overall with prestudy IBS medication, 69% of patients were satisfied or very satisfied overall with alosetron and 46% with placebo (p < 0.001) at the end of 12 wk of therapy. The majority of alosetron-treated patients (61-87%) were satisfied or very satisfied with each of 11 specific medication attributes (p < 0.001 vs placebo for each attribute). Favorable satisfaction ratings for alosetron were assigned to the five medication attributes that patients considered to be most important, including relief of urgency (68% alosetron vs 41% placebo), speed of relief (71% vs 40%), time to return to normal activities (75% vs 49%), relief of abdominal pain (62% vs 44%), and prevention of return of urgency (68% vs 42%). CONCLUSIONS Women with diarrhea-predominant IBS are satisfied with alosetron 1 mg b.i.d. treatment overall and also with respect to specific attributes of IBS medication they consider most important.
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Affiliation(s)
- Kevin Olden
- Mayo Clinic Scottsdale, Scottsdale, Arizona, USA
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37
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Abstract
There are many cell surface receptors expressed by neurones in the enteric nervous system (ENS). These receptors respond to synaptically released neurotransmitters, circulating hormones and locally released substances. Cell surface receptors are also targets for many therapeutically used drugs. This review will focus on ligand-gated ion channels, i.e. receptors in which the ligand binding site and the ion channel are parts of a single multimeric receptor. Ligand-gated ion channels expressed by enteric nerves are: nicotinic acetylcholine receptors (nAChRs), P2X receptors, 5-hydroxytryptamine3 (5-HT3) receptors, gamma-aminobutyric acid (GABAA) receptors, N-methyl-d-aspartate (NMDA) receptors,alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and glycine receptors. P2X, 5-HT3 and nAChRs participate in fast synaptic transmission in S-type neurones in the ENS. Fast synaptic transmission occurs in some AH-type neurones, and AH neurones express all the ligand-gated ion channels listed above. Ligand-gated ion channels may be localized at extra-synaptic sites in some AH neurones and these extra-synaptic receptors may be useful targets for drugs that can be used to treat disorders of gastrointestinal function.
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Affiliation(s)
- J J Galligan
- Department of Pharmacology and Toxicology and the Neuroscience Program, Michigan State University, East Lansing 48824, USA.
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Clemens CHM, Samsom M, Van Berge Henegouwen GP, Fabri M, Smout AJPM. Effect of alosetron on left colonic motility in non-constipated patients with irritable bowel syndrome and healthy volunteers. Aliment Pharmacol Ther 2002; 16:993-1002. [PMID: 11966509 DOI: 10.1046/j.1365-2036.2002.01252.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Alosetron is a 5-hydroxytryptamine-3 receptor antagonist reducing symptoms in female patients with diarrhoea-predominant irritable bowel syndrome, and is known to increase the colonic transit time. AIM To study the effect of alosetron on left colonic phasic motility in ambulant non-constipated patients with irritable bowel syndrome and healthy volunteers. METHODS In a double-blind, randomized, crossover design, 10 patients with irritable bowel syndrome and 12 sex- and age-matched volunteers were treated for two 7-day periods with alosetron, 4 mg b.d., or placebo b.d. On day 6 of each treatment period, a six-channel solid-state manometric catheter was positioned in the left colon and 24 h motility was studied on day 7. The periprandial phasic motility around dinnertime was evaluated in the descending and sigmoid colon. The high-amplitude propagated contraction frequency and characteristics were calculated. RESULTS Alosetron appeared to increase the overall periprandial frequency in the sigmoid colon (P=0.043) and the mean amplitude of colonic contractions in the descending colon (P=0.007). The high-amplitude propagated contraction frequency was higher on alosetron during the second half of the day for patients with irritable bowel syndrome (P=0.002), with increased mean propagation length of high-amplitude propagated contractions (P=0.001). The stool frequency (P=0.024) and stool consistency score (P=0.002) were decreased by alosetron. CONCLUSIONS The 5-hydroxytryptamine-3 receptor antagonist alosetron marginally increased left colonic periprandial phasic motility. Alosetron increased the number and propagation length of high-amplitude propagated contractions, which were paradoxically accompanied by a decrease in stool frequency and a firming of stool consistency.
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Affiliation(s)
- C H M Clemens
- Gastrointestinal Research Unit, Departments of Gastroenterology and Surgery, University Medical Center Utrecht, The Netherlands
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39
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Abstract
5-HT research is now more than 50 years old, and it has generated a wealth of therapeutic agents, some of which have had a major impact on disease management. The 5-HT reuptake inhibitors (SSRIs) are among the most widely prescribed drugs for treating depression and a variety of other disorders including anxiety, social phobia and premenstrual dysphoria (PMD). The other major success stories of 5-HT research are the discovery of 5-HT1B/D receptor agonists for treating migraine and 5-HT3 receptor antagonists for chemotherapy and radiation-induced emesis. The role of 5-HT in the mechanism of action of antipsychotic agents remains a topic of intense research, which promises better treatments for schizophrenia in the future. Compounds interacting with 5-HT1F, 5-HT2C, 5-HT6 and 5-HT7 receptors are currently under investigation and may prove to have important therapeutic applications in the future.
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Affiliation(s)
- Brian J Jones
- Psychiatry Research Department, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, CM19 5AW, Essex, UK.
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40
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Abstract
Functional abdominal pain can occur in a well-defined clinical entity (e.g., IBS) or as a part of a poorly defined clinical syndrome. Although the clinician may feel compelled to exclude disease in all cases, the authors suggest that it is more appropriate to take a biopsychosocial approach. In so doing, there can be an appreciation of the close interaction of the gut and the brain, allowing the child, family, and physician the opportunity to address the pain on many levels. Although the parameters set forth by the pediatric ROME II committee have facilitated the authors' description of these disorders greatly, basic research likely will further delineate biochemical processes in the enteric and central nervous systems that will expand therapeutic horizons.
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Affiliation(s)
- Donna K Zeiter
- Division of Digestive Diseases and Nutrition, Connecticut Children's Medical Center, Hartford, USA
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41
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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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42
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Abstract
Irritable bowel syndrome is a common gastrointestinal disorder characterized by abdominal pain and a change in bowel habits. It is estimated to occur in 9% to 22% of the US population, and is more often diagnosed in women than in men. There are no diagnostic markers for irritable bowel syndrome and no evidence of organic disease. Moreover, the pathophysiology is not completely understood; however, abnormal gastrointestinal motility, altered sensory activity, central neural dysfunction, psychological disturbances, and luminal factors have been proposed. Treatment requires a multifaceted approach. Education, dietary measures, fiber supplementation, and pharmacological and psychological interventions have been used in the management of this disorder.
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Affiliation(s)
- M L Borum
- Division of Gastroenterology, Department of Medicine, George Washington University Medical Center, Washington, DC 20037, USA
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Kobayashi S, Ikeda K, Suzuki M, Yamada T, Miyata K. Effects of YM905, a novel muscarinic M3-receptor antagonist, on experimental models of bowel dysfunction in vivo. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 86:281-8. [PMID: 11488427 DOI: 10.1254/jjp.86.281] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We investigated the effects of YM905 [(+)-(1S,3'R)-quinuclidin-3'-yl 1-phenyl-1,2,3,4-tetrahydroisoquinoline-2-carboxylate monosuccinate], a new orally active muscarinic M3-receptor antagonist, on bowel dysfunction in vivo using experimental models that reproduce the symptoms present in irritable bowel syndrome (IBS). YM905 potently inhibited restraint stress-induced fecal pellet output in fed rats (ED50: 4.0 mg/kg) and diarrhea in fasted rats (ED50: 1.7 mg/kg), with similar potencies to the inhibition of bethanechol-, neostigmine- and nicotine-induced fecal pellet output in rats (ED50: 3.3, 7.9 and 4.5 mg/kg, respectively). YM905 also inhibited 5-hydroxytryptamine (5-HT)-, prostaglandin E2- and castor oil-induced secretory diarrhea in mice (ED50: 5.5, 14 and 6.3 mg/kg, respectively), but showed no significant effect on cholera toxin-induced intestinal secretion in mice. In addition, YM905 (3, 10 mg/kg) reversed morphine-decreased postprandial defecation in ferrets, a model of spastic constipation, whereas remosetron, a 5-HT3-receptor antagonist, was not effective. The mode of YM905 action was similar to that of darifenacin, a selective M3-receptor antagonist, with equivalent potencies. By contrast, propantheline, an antimuscarinic drug that has been used for IBS, was much less potent. These results show that YM905 ameliorates a wide spectrum of bowel dysfunctions through the blockade of M3 receptors, suggesting its therapeutic potential for treating IBS.
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Affiliation(s)
- S Kobayashi
- Pharmacology Laboratories, Institute for Drug Discovery Research, Yamanouchi Pharmaceutical Co., Ltd., Tsukuba-shi, Ibaraki, Japan.
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44
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Abstract
Gastrointestinal disease is common in women and therefore a commonly encountered entity in gynecologic practice. A new understanding of the underlying pathophysiology of the most common condition, irritable bowel syndrome, is changing both diagnosis and therapy.
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Affiliation(s)
- R P Smith
- Department of Obstetrics and Gynecology, Truman Medical Center, University of Missouri at Kansas City, Kansas City, Missouri, USA
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45
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Abstract
Intestinal motility, secretion, and blood flow are controlled and integrated by the enteric nervous system (ENS). The ENS is like a "brain-in-the-gut," with many of the neurophysiologic properties of the central nervous system. Serotonin is a neurotransmitter at synapses in the microcircuits of the ENS. Serotonin is also released from enterochromaffin cells and inflammatory/immune cells to act at serotonergic receptors on neurons of the ENS. Four important actions are (1) fast and (2) slow excitation of enteric neurons, (3) presynaptic inhibition of neurotransmitter release at synapses in ENS microcircuits, and (4) excitation of intestinal sensory afferent fibers. Fast excitation and stimulation of sensory afferents are mediated by 5-HT(3) serotonergic receptors and slow excitation by 5-HT(1P) receptors. Presynaptic inhibitory receptors are not conclusively defined. The efficacy of a new 5-HT(3) receptor blocking drug in the treatment of the diarrhea-predominant form of the irritable bowel syndrome in women suggests the importance of this receptor subtype in the mediation of neurogenic secretory diarrhea, motility abnormality, and abdominal pain and discomfort.
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Affiliation(s)
- J D Wood
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210, USA.
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46
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Affiliation(s)
- D K Zeiter
- University of Connecticut, Division of Pediatric Digestive Diseases and Nutrition, Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT 06106, USA
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47
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Abstract
Patients with IBS need an integrated, individualized approach to treatment, with a foundation based on a successful patient-physician relationship. The emotional and psychologic needs of the patients need to be considered in a successful management plan. Further advances in the pathophysiology of disease are essential to develop suitable and more comprehensive treatment options.
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Affiliation(s)
- R D Rothstein
- Division of Gastroenterology, Pennsylvania Hospital, University of Pennsylvania Health System, Philadelphia, USA
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48
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Cada DJ, Baker DE, Levien T. Alosetron. Hosp Pharm 2000. [DOI: 10.1177/001857870003500608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Each month, subscribers to The Formulary® Monograph Service receive five to six researched monographs on drugs that are newly released or are in late Phase III trials. The monographs are targeted to your Pharmacy and Therapeutics Committee. Subscribers also receive monthly one-page summary monographs on the agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation (DUE) is also provided each month. The monographs are published in printed form and on diskettes that allow customization. Subscribers to the The Formulary Monograph Service also receive access to a pharmacy bulletin board called The Formulary Information Exchange (The F.I.X). All topics pertinent to clinical pharmacy are discussed on The F.I.X. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. If you would like information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The June 2000 Formulary monographs are on pantoprazole, oral and intravenous; meloxicam; zonisamide; gentuzum-ab zogamicin; and vertiporfin. The DUE is on meloxicam.
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Affiliation(s)
- Dennis J. Cada
- The Formulary; College of Pharmacy, Washington State University at Spokane, 601 West First Avenue, Spokane, WA 99201-3899
| | - Danial E. Baker
- The Formulary; College of Pharmacy, Washington State University at Spokane, 601 West First Avenue, Spokane, WA 99201-3899
| | - Terri Levien
- The Formulary; College of Pharmacy, Washington State University at Spokane, 601 West First Avenue, Spokane, WA 99201-3899
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49
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Houghton LA, Foster JM, Whorwell PJ. Alosetron, a 5-HT3 receptor antagonist, delays colonic transit in patients with irritable bowel syndrome and healthy volunteers. Aliment Pharmacol Ther 2000; 14:775-82. [PMID: 10848662 DOI: 10.1046/j.1365-2036.2000.00762.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Alosetron is a potent and selective 5-HT3 receptor antagonist, which has been shown to be beneficial in the treatment of female patients with non-constipated irritable bowel syndrome. AIMS To investigate the effect of alosetron on whole gut, small bowel and colonic transit in patients with irritable bowel syndrome (Study 1) and healthy volunteers (Study 2). SUBJECTS Thirteen patients with irritable bowel syndrome and 12 healthy volunteers. METHODS Both studies were randomized, double-blind, placebo-controlled with a two-way crossover design, in which each subject received alosetron (2 mg b.d. administered orally) or placebo for 8 days. Mean whole gut transit was determined from the excretion of radio-opaque markers; small bowel transit was determined from rise in breath hydrogen after a meal; and colonic transit and segmental transit were evaluated from abdominal X-ray. In addition, colonic transit was calculated by subtracting small bowel transit time from whole gut transit time. RESULTS Alosetron increased colonic transit time by prolonging left colonic transit in both patients with irritable bowel syndrome and controls. This resulted in a tendency for the whole gut transit to be delayed in irritable bowel syndrome patients (P=0.128), which was confirmed in controls (P=0.047). CONCLUSION Alosetron delays colonic transit by prolonging left colonic transit. These results add to the body of evidence suggesting that alosetron should have a therapeutic role in patients with non-constipated irritable bowel syndrome.
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Affiliation(s)
- L A Houghton
- Department of Medicine, University Hospital of South Manchester, Manchester, UK.
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50
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Abstract
Alone among organs of the body, the gut is able to mediate reflexes in the absence of input from the brain or spinal cord. This ability appears to be caused by the secretion of serotonin (5-HT) by enterochromaffin (EC) cells of the mucosal epithelium. This 5-HT is secreted into the wall of the gut, where it stimulates the mucosal processes of intrinsic and extrinsic primary afferent neurons. The intrinsic primary afferents, which are activated by 5-HT1P/4 receptors, initiate peristaltic and secretory reflexes. The extrinsic primary afferent neurons send distress and other signals to the central nervous system. Extrinsic nerves are activated by 5-HT(3) receptors. The 5-HT that is involved in mucosal signaling is inactivated by uptake into mucosal epithelial cells, which are mediated by an integral membrane protein called the serotonin reuptake transporter (SERT). The epithelial SERT is the same molecule as that which transports 5-HT in the central and enteric nervous systems. Increasing evidence suggests that abnormal enteric release or inactivation of 5-HT is involved in the pathogenesis of irritable bowel syndrome (IBS). Spread of 5-HT to inappropriate sites in IBS may activate 5-HT(3) receptors on extrinsic afferent fibers and motor neurons, giving rise to visceral hypersensitivity and abnormal motility, respectively. A potent 5-HT(3) antagonist, such as alosetron, can prevent both of these effects and is therefore useful in treating IBS. 5-HT also appears to function as a growth factor in the development of enteric neurons. The developmental effects of 5-HT are mediated by the 5-HT(2B) receptor, which is developmentally regulated. The importance of serotonergic mechanisms in enteric physiology probably accounts for the gastrointestinal "side effects" of compounds that inhibit SERT. The newly discovered role of 5-HT in enteric neuronal development suggests that drugs that interfere with the action or inactivation of 5-HT should be used in pregnancy only with extreme caution, if at all.
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Affiliation(s)
- M D Gershon
- Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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