Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Irritable bowel syndrome (IBS) is a common disorder associated with abdominal pain or discomfort and altered bowel habits. The majority of patients describe an insidious onset of symptoms; however, a subset report a fairly precise time of onset following an attack of acute gastroenteritis. Typically, the potential acute infectious symptoms, such as fever and vomiting, resolve after several days, but abdominal discomfort, bloating, and diarrhea persist. Although the underlying mechanism of post-infectious IBS (PI-IBS) has not been established, ongoing inflammation appears to play a role, with an increase in serotonin-containing enterochromaffin cells, T lymphocytes, mast cells, proinflammatory cytokines, and intestinal permeability. Psychiatric comorbidities are less common in PI-IBS, compared with IBS patients in general; however, the prevalence of psychological disorders is still higher compared with that in the general population and is associated with a poorer prognosis. Overall, patients with PI-IBS have a slightly improved prognosis compared with those with IBS without an infectious onset.
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PMID:Post-infectious irritable bowel syndrome. 1799 38

5-Hydroxytryptamine (serotonin) (5-HT) is a neurotransmitter with both central and peripheral functions, including the modulation of mood, appetite, hemodynamics, gastrointestinal (GI) sensation, secretion, and motility. Its synthesis is initiated by the enzyme tryptophan hydroxylase (TPH). Two isoforms of TPH have been discovered: TPH1, primarily expressed in the enterochromaffin cells of the gastrointestinal tract, and TPH2, expressed exclusively in neuronal cells. Mice lacking Tph1 contain little to no 5-HT in the blood and GI tract while maintaining normal levels in the brain. Because GI 5-HT is known to play important roles in normal and pathophysiology, we set out to discover and characterize novel compounds that selectively inhibit biosynthesis of GI 5-HT. Here, we describe two of a series of these inhibitors that are potent for TPH activity both in biochemical and cell-based assays. This class of compounds has unique properties with respect to pharmacokinetic and pharmacodynamic effects on GI serotonin production. Similar to the Tph1 knockout results, these TPH inhibitors have the ability to selectively reduce 5-HT levels in the murine GI tract without affecting brain 5-HT levels. In addition, administration of these compounds in a ferret model of chemotherapy-induced emesis caused modest reductions of intestinal serotonin levels and a decreased emetic response. These findings suggest that GI-specific TPH inhibitors may provide novel treatments for various gastrointestinal disorders associated with dysregulation of the GI serotonergic system, such as chemotherapy-induced emesis and irritable bowel syndrome.
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PMID:Discovery and characterization of novel tryptophan hydroxylase inhibitors that selectively inhibit serotonin synthesis in the gastrointestinal tract. 1819 99

5-Hydroxytryptamine, or serotonin, is a biogenic amine most noted for its role as a neurotransmitter. Manipulation of serotonin in animal models was used as a tool for studying its role in humans. Through such research serotonin has been shown to modulate gastrointestinal motility, peripheral vascular tone, cerebral vascular tone, and platelet function and has been implicated in the pathophysiology of mood disorders, emesis, migraine, irritable bowel syndrome (IBS), and pulmonary and systemic hypertension. The knowledge gained is being directly applied back to animals in research on drugs that manipulate the serotonergic system in dogs and cats. Increasing use and availability of drugs that manipulate the serotonergic system has created a circumstance through which a novel toxicity was discovered in both humans and animals. Serotonin Syndrome describes the clinical picture seen in humans and animals with serotonin toxicity. This paper provides a review the physiology of serotonin and its involvement in the pathophysiologic mechanisms of various conditions, including the Serotonin Syndrome.
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PMID:Serotonin: a review. 1847 Nov 39

Loperamide is an effective therapy for a variety of diarrheal syndromes, including acute, nonspecific (infectious) diarrhea; traveler's diarrhea; and chemotherapy-related and protease inhibitor?associated diarrhea. Loperamide is effective for the "gut-directed" symptom of diarrhea in patients with painless diarrhea or diarrhea-predominant irritable bowel syndrome. Loperamide and diphenoxylate are commonly used to treat diarrhea in numerous settings of inflammatory bowel disease. Loperamide has also been observed to increase anal sphincter tone, which may lead to improvement of fecal continence in patients with and without diarrhea. Loperamide is generally well tolerated at recommended nonprescription doses, with the most common side effects related to the impact on bowel motility (abdominal pain, distention, bloating, nausea, vomiting, and constipation).
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PMID:The role of loperamide in gastrointestinal disorders. 1847 66

The discovery of a novel class of peripheral tryptophan hydroxylase (TPH) inhibitors is described. This class of TPH inhibitors exhibits excellent potency in in vitro biochemical and cell-based assays, and it selectively reduces serotonin levels in the murine intestine after oral administration without affecting levels in the brain. These TPH1 inhibitors may provide novel treatments for gastrointestinal disorders associated with dysregulation of the serotonergic system, such as chemotherapy-induced emesis and irritable bowel syndrome.
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PMID:Modulation of peripheral serotonin levels by novel tryptophan hydroxylase inhibitors for the potential treatment of functional gastrointestinal disorders. 1855 9

Functional gastrointestinal disorders continue to be a prevalent set of conditions faced by the healthcare team and have a significant emotional and economic impact. In this review, the authors highlight some of the common functional disorders seen in pediatric patients (functional dyspepsia, irritable bowel syndrome, functional abdominal pain) as well as one of the more intriguing (cyclic vomiting). The most recent Pediatric Rome Working Group has modified the definitions of functional gastrointestinal disorders. Current studies have used these categorizations to understand better the epidemiology, etiology, and treatment options for these disorders. As more data are available, children and their families will be offered a better understanding of the conditions and more effective treatments to overcome them. The importance of making an accurate diagnosis of a functional gastrointestinal disorder cannot be overemphasized.
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PMID:Pediatric functional gastrointestinal disorders. 1859 59

The 5-hydroxytryptamine 3 (5-HT3) receptor is expressed widely in the central and peripheral nervous systems, where it mediates or modulates a wide range of physiological processes. The receptor is targeted by drugs administered for nausea and/or emesis and irritable bowel syndrome and has been proposed as a potential drug target in various psychiatric disorders. The 5-HT3 receptor is a pentameric ligand-gated ion channel and belongs to the Cys-loop receptor family. In contrast to the immense heterogeneity characterizing other Cysloop receptors, native 5-HT3 receptors historically have been considered a much more homogenous receptor population. However, the recent discovery of additional 5-HT3 subunits and the dawning realization that central and peripheral 5-HT3 receptor populations might comprise several subtypes characterized by distinct functional properties has emphasized the complexity of human 5-HT3 receptor signaling. In this review potential implications of these findings and of the entirely new layer of interindividual diversity introduced to the 5-HT3 receptor system by genetic variations will be outlined.
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PMID:3B but which 3B and that's just one of the questions: the heterogeneity of human 5-HT3 receptors. 1859 59

Gastrointestinal symptoms are extremely common during pregnancy. Increased levels of female sex hormones cause or contribute to symptoms such as heartburn, nausea, vomiting and constipation. If these symptoms do not respond adequately to lifestyle and dietary changes, drug therapy is often warranted to improve quality of life and to prevent complications. Physicians, therefore, need to be familiar with the low-risk treatment options available. Treatment of chronic conditions such as IBD or chronic liver disease during pregnancy can be demanding. In women with IBD, maintenance of adequate disease control during pregnancy is crucial. Most IBD drugs can be used during pregnancy, but the benefits and risks of specific drugs should be discussed with the patient. Liver diseases can be coincidental or pregnancy-specific. Pregnancy-specific liver diseases include not only benign disorders such as intrahepatic cholestasis of pregnancy, but also pre-eclampsia, eclampsia and HELLP syndrome (hemolytic anemia, elevated liver enzymes and low platelet count). Accordingly, the spectrum of therapeutic measures ranges from expectant management to urgent induction of delivery. During pregnancy, lamuvidine therapy for chronic hepatitis B can be continued; however, interferon and ribavirin therapy for chronic hepatitis C is contraindicated. This Review provides an overview of the spectrum and therapy of motility disturbances that occur during pregnancy, and discusses pregnancy-specific aspects of IBD and liver diseases.
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PMID:The spectrum and treatment of gastrointestinal disorders during pregnancy. 1925 5

Nerve, muscle, and inflammatory cells involved in gastrointestinal (GI) function have high-energy requirements and are affected in mitochondrial disorders. Familial aggregation of irritable bowel syndrome (IBS) frequently involves mothers and their children. Since mitochondrial DNA (mtDNA) is maternally inherited, mtDNA single nucleotide polymorphisms (SNPs) could confer risk to the development of IBS. The mtDNA SNPs, 16519C>T and 3010G>A, are associated with migraine and childhood cyclic vomiting syndrome. Our hypothesis is that these mtDNA SNPs are associated with functional GI disorders (FGIDs) and GI functions. The mt genome was first tested for the 7028C polymorphism (defining haplogroup H) in 699 patients or controls, and those with 7028C were further genotyped at 16519 and 3010. Phenotypes were based on symptoms (validated questionnaires and criteria) and GI physiology using validated motor and sensory studies. Constipation-predominant IBS and alternating constipation and diarrhea IBS are less prevalent in individuals with the 7028C mtDNA polymorphism than in individuals with 7028T. Conversely, 7028C is associated with higher maximum tolerated volume (lower satiation) compared with 7028T. Among those with 7028C, nonspecific abdominal pain (chronic abdominal pain or dyspepsia) was significantly associated with 3010A compared with 3010G (odds ratio 3.3, P=0.02), and slower gastric emptying was statistically associated with 3010G. There were no significant associations of mtDNA genotypes tested and stomach volumes, small bowel or colonic transit, rectal compliance, and motor or sensory functions. Thus variation in mtDNA may be associated with satiation, gastric emptying, and possibly pain; further studies of mtDNA in appetite regulation and larger numbers of patients with FGIDs are warranted.
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PMID:Mitochondrial DNA and gastrointestinal motor and sensory functions in health and functional gastrointestinal disorders. 1914 1

Tryptophan hydroxylase (TPH) is a key enzyme in the synthesis of serotonin. As a neurotransmitter, serotonin plays important physiological roles both peripherally and centrally. Here we describe the discovery of substituted triazines as a novel class of tryptophan hydroxylase inhibitors. This class of TPH inhibitors can selectively reduce serotonin levels in murine intestine after oral administration without affecting levels in the brain. These TPH inhibitors may provide novel treatments for gastrointestinal disorders associated with dysregulation of the serotonergic system, such as chemotherapy-induced emesis and irritable bowel syndrome.
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PMID:Substituted 3-(4-(1,3,5-triazin-2-yl)-phenyl)-2-aminopropanoic acids as novel tryptophan hydroxylase inhibitors. 1963 32


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