Home About us Contact
|
Home About us Contact | ||
|
|
||
Gastrointestinal Motility (gastrointestinal + motility)
Terms modified by Gastrointestinal Motility Selected AbstractsList of Abstracts by Topic submitted to the 19th International Symposium on Gastrointestinal Motility held in Barcelona from October, 5th to 8th, 2003.NEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2003Article first published online: 24 SEP 200 First page of article [source] Gastrointestinal motility and the brain-gut axisDIGESTIVE ENDOSCOPY, Issue 2 2003TADASHI ISHIGUCHI The role of the brain-gut axis in gastrointestinal motility is discussed according to the specific organs of the gastrointestinal tract. Not only clinical studies but basic animal research are reviewed. Although the mechanism of functional gut disorders remains to be clarified, recent data suggest that there is evidence that the brain-gut axis has significant effects on gastrointestinal motility. The major role of endoscopy in the diagnosis of functional gastrointestinal disorders is to exclude organic gastrointestinal disorders. In the esophagus, the lower esophageal sphincter and a gamma-aminobutyric acid B mechanism are considered to play important roles in gastroesophageal reflux disease. In the stomach, corticotropin-releasing factor, neuropeptide Y and other substances might be involved in the pathogenesis of non-ulcer dyspepsia. In the small intestine, corticotropin-releasing factor, gamma-aminobutyric acid B and other substances are considered to modulate intestinal transit via central mechanisms. In the colon, it is known that psychiatric factors are related to the onset and clinical course of irritable bowel syndrome. Serotonin, corticotropin-releasing factor, gamma-aminobutyric acid, orphanin FQ and neuropeptide Y have been reported as putative neurotransmitters. More efforts in basic science studies and animal and human studies of physiology of the gastointestinal tract are still required. These efforts will elucidate further mechanisms to clarify the etiology of motility disorders and encourage the investigation of new therapies in this field. [source] Neural stem cells for the treatment of disorders of the enteric nervous system: Strategies and challengesDEVELOPMENTAL DYNAMICS, Issue 1 2007Maria-Adelaide Micci Abstract The main goal of this review is to summarize the status of the research in the field of stem cells transplantation, as it is applicable to the treatment of gastrointestinal motility. This field of research has advanced tremendously in the past 10 years, and recent data produced in our laboratories as well as others is contributing to the excitement on the use of neural stem cells (NSC) as a valuable therapeutic approach for disorders of the enteric nervous system characterized by a loss of critical neuronal subpopulations. There are several sources of NSC, and here we describe therapeutic strategies for NSC transplantation in the gut. These include using NSC as a relatively nonspecific cellular replacement strategy in conditions where large populations of neurons or their subsets are missing or destroyed. As with many other recent "breakthroughs" stem cell therapy may eventually prove to be overrated. However, at the present time, it does appear to provide the hope for a true cure for many currently intractable diseases of both the central and the peripheral nervous system. Certainly more extensive research is needed in this field. We hope that our review will encourage new investigators in entering this field of research ad contribute to our knowledge of the potentials of NSC and other cells for the treatment of gastrointestinal dysmotility. Developmental Dynamics 236:33,43, 2007. © 2006 Wiley-Liss, Inc. [source] Therapy of type 2 diabetes mellitus based on the actions of glucagon-like peptide-1DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2002Jens Juul Holst Abstract GLP-1 is a peptide hormone from the intestinal mucosa. It is secreted in response to meal ingestion and normally functions in the so-called ileal brake, that is, inhibition of upper gastrointestinal motility and secretion when nutrients are present in the distal small intestine. It also induces satiety and promotes tissue deposition of ingested glucose by stimulating insulin secretion. Thus, it is an essential incretin hormone. In addition, the hormone has been demonstrated to promote insulin biosynthesis and insulin gene expression and to have trophic effects on the beta cells. The trophic effects include proliferation of existing beta cells, maturation of new cells from duct progenitor cells and inhibition of apoptosis. Furthermore, glucagon secretion is inhibited. Because of these effects, the hormone effectively improves metabolism in patients with type 2 diabetes mellitus. Thus, continuous subcutaneous administration of the peptide for six weeks in patients with rather advanced disease greatly improved glucose profiles and lowered body weight, haemoglobin A1C, and free fatty acids (FFA). In addition, insulin sensitivity doubled and insulin responses to glucose were greatly improved. There were no side effects. Continuous administration is necessary because of rapid degradation by the enzyme dipeptidyl peptidase-IV. Alternative approaches include the use of analogues that are resistant to the actions of the enzyme, as well as inhibitors of the enzyme. Both approaches have shown remarkable efficacy in both experimental and clinical studies. The GLP-1-based therapy of type 2 diabetes, therefore, represents a new and attractive alternative. Copyright © 2002 John Wiley & Sons, Ltd. [source] Gastrointestinal motility and the brain-gut axisDIGESTIVE ENDOSCOPY, Issue 2 2003TADASHI ISHIGUCHI The role of the brain-gut axis in gastrointestinal motility is discussed according to the specific organs of the gastrointestinal tract. Not only clinical studies but basic animal research are reviewed. Although the mechanism of functional gut disorders remains to be clarified, recent data suggest that there is evidence that the brain-gut axis has significant effects on gastrointestinal motility. The major role of endoscopy in the diagnosis of functional gastrointestinal disorders is to exclude organic gastrointestinal disorders. In the esophagus, the lower esophageal sphincter and a gamma-aminobutyric acid B mechanism are considered to play important roles in gastroesophageal reflux disease. In the stomach, corticotropin-releasing factor, neuropeptide Y and other substances might be involved in the pathogenesis of non-ulcer dyspepsia. In the small intestine, corticotropin-releasing factor, gamma-aminobutyric acid B and other substances are considered to modulate intestinal transit via central mechanisms. In the colon, it is known that psychiatric factors are related to the onset and clinical course of irritable bowel syndrome. Serotonin, corticotropin-releasing factor, gamma-aminobutyric acid, orphanin FQ and neuropeptide Y have been reported as putative neurotransmitters. More efforts in basic science studies and animal and human studies of physiology of the gastointestinal tract are still required. These efforts will elucidate further mechanisms to clarify the etiology of motility disorders and encourage the investigation of new therapies in this field. [source] Fifty years of Australian pediatric gastroenterologyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2009Don Cameron Abstract When the Gastroenterological Society of Australia (GESA) began 50 years ago there were very few pediatric gastroenterologists in the world. The ,Mother' of Paediatric Gastroenterology was Australian Charlotte (,Charlo') Anderson who established one of the world's first pediatric gastroenterology units in Melbourne in the early 1960s. Her earlier work in Birmingham had identified gluten as the component of wheat responsible for celiac disease and helped separate maldigestion (cystic fibrosis) and mucosal malabsorption. The first comprehensive textbook of Paediatric Gastroenterology was edited by Charlotte Anderson and Valerie Burke in 1975. Rudge Townley succeeded Charlotte Anderson in Melbourne and went on to further develop small bowel biopsy techniques making it a safe, simple, and quick procedure that led to much greater understanding of small bowel disease and ultimately the discovery of Rotavirus by Ruth Bishop et al. and subsequently to Rotavirus immunization. Australian Paediatric Gastroenterology subsequently developed rapidly with units being established in all mainland capital cities by the end of the 1970s. The Australian Society of Paediatric Gastroenterology Hepatology and Nutrition (AuSPGHAN) was established in the 1980s. Australians have contributed significantly in many areas of gastroenterology in infants, children, and adolescents including celiac disease, cystic fibrosis, liver disease, transplantation, gastrointestinal infection, allergy, indigenous health, inflammatory bowel disease, gastrointestinal motility, and the development of novel tests of gastrointestinal function and basic science. There have also been major contributions to nutrition in cystic fibrosis, end-stage liver disease, and intestinal failure. The future of Australian Paediatric Gastroenterology is in good hands. [source] Effects and probable mechanisms of electroacupuncture at the Zusanli point on upper gastrointestinal motility in rabbitsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2007Wei-Xin Niu Abstract Background and Aim:, The purposes of this study were to investigate the regulative effect of acupuncture on gastrointestinal motility in rabbits and to explore the probable mechanism of electroacupuncture. Methods:, The experiment was performed on 30 rabbits implanted with three pairs of electrodes, which were equally divided into three groups: the control group, the Zusanli group, and the non-acupuncture point group. The gastrointestinal myoelectrical activity of each conscious rabbit was recorded when acupuncture was applied. Motilin in plasma, cholecystokinin (CCK) in serum, the activity of acetylcholine esterase, nitric oxide synthase (NOS), and the vesicle of nerve endings in the stomach tissue and jejunum were investigated. Results:, It was found that electroacupuncture did not exert much influence on the slow wave of gastrointestinal myoelectrical activity, but significantly increased the number and amplitude of spikes. In the Zusanli group, the concentration of motilin and CCK was much higher at the post-acupuncture stage than at the pre-acupuncture stage. Electroacupuncture significantly enhanced the activity of acetylcholine esterase. Moreover, we found out that in the Zusanli group, the number of vesicles without granula was significantly fewer than in the control group. The activity of NOS was less in the Zusanli group than in the control group. Conclusions:, Acupuncture may enhance the gastrointestinal myoelectrical activity of conscious rabbits. The cholinergic nerve, nitric oxide, motilin, and CCK may contribute to acupuncture mechanisms. [source] Gastric electrical activity in patients with cholelithiasis undergoing laparoscopic cholecystectomy: A prospective controlled studyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2004SPIROS N SGOUROS Abstract Background:, The aim of the present study was to evaluate the effect of gallstone disease (GD) and laparoscopic cholecystectomy on gastric electrical activity of slow waves, which was recorded via transcutaneous electrogastrography (EGG). Methods:, Twenty-one consecutive patients (M/F: 12/9, 52.7 ± 15 years old) with GD and no previous history of abdominal operations or known disease affecting gastrointestinal motility were studied. The EGG was performed for 30 min prior to and 90 min after a standard meal, during a 4,6 month period prior to and after laparoscopic cholecystectomy. The percentile proportion of the three spectra of gastric slow waves frequency was studied, defined as follows: bradygastria, 1,2.1 cycles per min (c.p.m.); normogastria, 2.2,3.9 c.p.m.; and tachygastria, 4,9 c.p.m. The findings were compared to those of nine healthy subjects (M/F: 5/4, 49.5 ± 14.8 years old). Results:, No statistically significant difference was found in percentile distribution of bradygastria, normogastria and tachygastria, pre- or post-prandially, neither before or after laparoscopic cholecystectomy, nor between patients and controls. Conclusions:, Patients with GD do not exhibit differences in gastric electrical activity of slow waves in comparison to normal subjects and laparoscopic cholecystectomy does not alter gastric electrical activity. These findings suggest that cholelithiasis does not seem to cause dyspeptic symptoms due to gastric dysrythmias. [source] Gastrointestinal Regulation of Food Intake: General Aspects and Focus on Anandamide and OleoylethanolamideJOURNAL OF NEUROENDOCRINOLOGY, Issue 2008R. Capasso The gastrointestinal tract plays a pivotal role in the regulation of food intake and energy balance. Signals from the gastrointestinal tract generally function to limit ingestion in the interest of efficient digestion. These signals may be released into the bloodstream or may activate afferent neurones that carry information to the brain and its cognitive centres, which regulates food intake. The rate at which nutrients become systemically available is also influenced by gastrointestinal motility: a delay in gastric emptying may evoke a satiety effect. Recent evidence suggests that the endocannabinoid anandamide and the related acylethanolamide oleoylethanolamide are produced in the intestine and might regulate feeding behaviour by engaging sensory afferent neurones that converge information to specific areas of the brain. The intestinal levels of these acylethanolamides are inversely correlated to feeding, as food deprivation increases intestinal levels of anandamide (which acts in the gut as a ,hunger signal'), while it decreases the levels of oleoylethanolamide (which acts in the gut as a ,satiety signal'). Additionally, these acylethanolamides, whose gastric levels change in response to diet-induced obesity, alter gastrointestinal motility, which might contribute to their effect on food intake and nutrient absorption. [source] The influence of citalopram on interdigestive gastrointestinal motility in manALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2010P. Janssen Aliment Pharmacol Ther 2010; 32: 289,295 Summary Background, Administration of 5-hydroxytryptamine (5HT) and selective 5HT receptor ligands modifies interdigestive motility in animals and in man. Aim, To study the effect of citalopram, a selective 5-HT reuptake inhibitor, on interdigestive motility in man. Methods, In 20 healthy subjects, antroduodenojejunal motor activity was studied manometrically. Basal interdigestive motor activity was recorded until the passage of two activity fronts. Ten minutes after the second activity front, placebo or 20 mg of citalopram was administered intravenously in a double-blind randomized fashion. Recording continued until the passage of two more activity fronts had occurred. Results, Administration of citalopram induced a premature small intestinal phase 3 after 35 ± 6.4 min, compared to 120 ± 17 min after placebo P < 0.01. Citalopram shortened MMC cycle length at the expense of phase 1 and phase 2 and significantly increased the motility index during phase 2 in the antrum and the small intestine. Conclusions, In the interdigestive state in man, intravenous administration of the selective 5-HT reuptake inhibitor citalopram induces a premature intestinal phase 3 and suppresses gastric activity fronts. Phase 2 motility is stimulated both in the stomach and in the small bowel after citalopram. These data suggest that 5HT is involved in the control of interdigestive motility. [source] Erythromycin prior to endoscopy for acute upper gastrointestinal haemorrhage: a cost-effectiveness analysisALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2007N. S. WINSTEAD Summary Background, Erythromycin is a potent stimulator of gastrointestinal motility. Recent studies have examined the use of intravenous erythromycin to clear the stomach of blood before oesophago-gastroduodenoscopy (EGD) for acute upper gastrointestinal haemorrhage (UGIH). These studies have shown clinical effectiveness. Aim, To evaluate the cost-effectiveness of this intervention. Methods, We sought to determine the cost-effectiveness of erythromycin before EGD from the payer's perspective. We found three relevant studies of erythromycin and used these data for the analysis. We obtained costs for intravenous erythromycin and charges for peptic ulcer hospitalization, EGD, surgery, and angiographic embolization. Complication rates were also incorporated from the literature. We implemented a model of health-related quality of life to measure the impact of the intervention. We created a decision-analysis tree and performed a probabilistic sensitivity analysis. Results, A strategy of erythromycin prior to EGD resulted in a cost-effective outcome in a majority of trials using willingness-to-pay figures of $0, $50 000 and $100 000 (US) per quality-adjusted life-year (QALY). Conclusion, Because of the implications for cost saving and increase in QALY, we would recommend giving erythromycin prior to EGD for UGIH. [source] Review article: fructose malabsorption and the bigger pictureALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2007P. R. GIBSON Summary Fructose is found widely in the diet as a free hexose, as the disaccharide, sucrose and in a polymerized form (fructans). Free fructose has limited absorption in the small intestine, with up to one half of the population unable to completely absorb a load of 25 g. Average daily intake of fructose varies from 11 to 54 g around the world. Fructans are not hydrolysed or absorbed in the small intestine. The physiological consequences of their malabsorption include increasing osmotic load, providing substrate for rapid bacterial fermentation, changing gastrointestinal motility, promoting mucosal biofilm and altering the profile of bacteria. These effects are additive with other short-chain poorly absorbed carbohydrates such as sorbitol. The clinical significance of these events depends upon the response of the bowel to such changes; they have a higher chance of inducing symptoms in patients with functional gut disorders than asymptomatic subjects. Restricting dietary intake of free fructose and/or fructans may have durable symptomatic benefits in a high proportion of patients with functional gut disorders, but high quality evidence is lacking. It is proposed that confusion over the clinical relevance of fructose malabsorption may be reduced by regarding it not as an abnormality but as a physiological process offering an opportunity to improve functional gastrointestinal symptoms by dietary change. [source] Systematic review: applications and future of gastric electrical stimulationALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2006J. ZHANG Summary Background, Over the past 20 years, gastric electrical stimulation has received increasing attention among researchers and clinicians. Aim, To give a systematic review on the effects, mechanisms and applications of gastric electrical stimulation. Methods, Medline was used to identify the articles to be included in this review. Key words used for the search included gastric electrical stimulation, gastric pacing, electrical stimulation, stomach, gastrointestinal motility, central nervous system, gastroparesis, nausea and vomiting; obesity and weight loss. Combinational uses of these keywords were made to identify relevant articles. Most of the articles included in this review ranged from 1985 to 2006. Results, Based on the general search, the review was structured as follows: (i) peripheral and central effects and mechanisms of gastric electrical stimulation; (ii) clinical applications of gastric electrical stimulation for gastroparesis and obesity and (iii) future development of gastric electrical stimulation. Conclusions, Great progress has been made during the past decades. Gastric electrical stimulation has been shown to be effective in normalizing gastric dysrhythmia, accelerating gastric emptying and improving nausea and vomiting. Implantable device has been made available for treating gastroparesis as well as obesity. However, development of a new device and controlled clinical studies are required to further prove clinical efficacy of gastric electrical stimulation. [source] Review article: the role of serotonergic agents in the treatment of patients with primary chronic constipationALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11-12 2005B. D. CASH Summary Chronic constipation is a highly prevalent disorder that is associated with significant direct and indirect costs and has substantial impact on patient quality of life. It is more common among women and non-white populations and is evenly distributed across adult age groups. Constipation is a heterogeneous disorder associated with multiple symptoms and aetiologies. Recent research has increased our understanding of the pathogenesis of this disorder and the central role of the neurotransmitter serotonin in mediating gastrointestinal motility, secretion and sensation. Abnormal serotonin signalling and reuptake appear to play central roles in the symptoms of a subset of patients with chronic constipation. This observation provides a rationale for the use of targeted serotonergic agents for the treatment of chronic constipation. As the role of serotonin in gastrointestinal function is further elucidated and additional candidate drugs are developed, it is likely that serotonergic agents will afford additional treatment options for patients with chronic constipation. This article provides a concise review of the evidence supporting a role for serotonin in the pathogenesis of chronic constipation and a summary of the currently available evidence supporting the use of serotonergic agents for this disorder. [source] Review article: proteinase-activated receptors , novel signals for gastrointestinal pathophysiologyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2000Vergnolle Proteinase-activated receptors (PARs) have the common property of being activated by the proteolytic cleavage of their extracellular N-terminal domain. The new NH2 -terminus acts as a ,tethered ligand' binding and activating the receptor itself. Four members of this family have been cloned, three of which are activated by thrombin (PAR-1, PAR-3 and PAR-4) while the fourth (PAR-2) is activated by trypsin or mast cell tryptase. In physiological or pathophysiological conditions, the gastrointestinal tract is exposed more than other tissues to proteinases (digestive enzymes, proteinases from pathogens or proteinases from inflammatory cells) that can activate PARs. Since PARs are highly expressed throughout the gastrointestinal tract, the study of the role of PARs in these tissues appears to be particularly important. It has already been shown that PAR-2 activation induces calcium mobilization and eicosanoid production in enterocytes as well as changes in ion transport in jejunal tissue segments. PAR-2 activation also causes calcium mobilization and stimulates amylase release from pancreatic acini. Moreover, both PAR-1 and PAR-2 activation can alter the gastrointestinal motility. In inflammatory or allergic conditions, the proteinases that constitute the major agonists for PARs (thrombin, trypsin and mast cell tryptase) are usually released. The activation of PARs by these proteinases might contribute to the gastrointestinal disorders associated with these pathologies. A complete understanding of the role of PARs in the gastrointestinal tract will require the development of selective receptor antagonists that are not yet available. Nonetheless, the use of PAR agonists has already highlighted new potential functions for proteinases in the gastrointestinal tract, thus the control of PAR activation might represent a promising therapeutic target. [source] Neural control of the gastrointestinal tract: Implications for Parkinson diseaseMOVEMENT DISORDERS, Issue 8 2008Maria G. Cersosimo MD Abstract Disorders of swallowing and gastrointestinal motility are prominent nonmotor manifestations of Parkinson disease (PD). Motility of the gut is controlled both by extrinsic inputs from the dorsal motor nucleus of the vagus (DMV) and paravertebral sympathetic ganglia and by local reflexes mediated by intrinsic neurons of the enteric nervous system (ENS). Both the ENS and the DMV are affected by Lewy body pathology at early stages of PD. This early involvement provides insights into the pathophysiology of gastrointestinal dysmotility in this disorder and may constitute an important step in the etiopathogenesis of Lewy body disease. © 2008 Movement Disorder Society. [source] Differential effects of CB1 neutral antagonists and inverse agonists on gastrointestinal motility in miceNEUROGASTROENTEROLOGY & MOTILITY, Issue 7 2010M. A. Storr Abstract Background, Cannabinoid type 1 (CB1) receptors are involved in the regulation of gastrointestinal (GI) motility and secretion. Our aim was to characterize the roles of the CB1 receptor on GI motility and secretion in vitro and in vivo by using different classes of CB1 receptor antagonists. Methods, Immunohistochemistry was used to examine the localization of CB1 receptor in the mouse ileum and colon. Organ bath experiments on mouse ileum and in vivo motility testing comprising upper GI transit, colonic expulsion, and whole gut transit were performed to characterize the effects of the inverse agonist/antagonist AM251 and the neutral antagonist AM4113. As a marker of secretory function we measured short circuit current in vitro using Ussing chambers and stool fluid content in vivo in mouse colon. We also assessed colonic epithelial permeability in vitro using FITC-labeled inulin. Key Results,In vivo, the inverse agonist AM251 increased upper GI transit and whole gut transit, but it had no effect on colonic expulsion. By contrast, the neutral antagonist AM4113 increased upper GI transit, but unexpectedly reduced both colonic expulsion and whole gut transit at high, but not lower doses. Conclusions & Inferences, Cannabinoid type 1 receptors regulate small intestinal and colonic motility, but not GI secretion under physiological conditions. Cannabinoid type 1 inverse agonists and CB1 neutral antagonists have different effects on intestinal motility. The ability of the neutral antagonist not to affect whole gut transit may be important for the future development of CB1 receptor antagonists as therapeutic agents. [source] Actions of prolonged ghrelin infusion on gastrointestinal transit and glucose homeostasis in humansNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2010Y. Falkén Abstract Background, Ghrelin is produced by enteroendocrine cells in the gastric mucosa and stimulates gastric emptying in healthy volunteers and patients with gastroparesis in short-term studies. The aim of this study was to evaluate effects of intravenous ghrelin on gastrointestinal motility and glucose homeostasis during a 6-h infusion in humans. Methods, Ghrelin (15 pmol kg,1 min,1) or saline was infused intravenously for 360 min after intake of radio-opaque markers, acetaminophen, and lactulose after a standardized breakfast in 12 male volunteers. Gastric emptying, orocecal transit, colonic transit, postprandial plasma concentrations of glucose, insulin, glucagon-like peptide-1 (GLP-1), and peptide YY were assessed. In vitro studies of gastrointestinal muscle contractility were performed. Key Results, The gastric emptying rate was faster for ghrelin compared to saline (P = 0.002) with a shorter half-emptying time (50.3 ± 3.9 vs 59.9 ± 4.4 min, P = 0.004). There was no effect of ghrelin on orocecal or colonic transit. Postprandial elevations of plasma glucose, insulin, and GLP-1 occurred 15 min earlier and were higher with ghrelin. The insulinogenic index did not change during ghrelin infusion. Basal in vitro contractility was unaffected by ghrelin. Conclusions & Inferences, The effect of a 6-h ghrelin infusion on gastrointestinal motility is limited to the stomach without affecting orocecal or colonic transit. Plasma glucose, insulin, and GLP-1 are elevated postprandially, probably as a result of the hastened gastric emptying. Changes in glucose homeostasis as a consequence of stimulated gastric emptying and hormone release, need to be taken into account in the use of pharmacological stimulants for the treatment of motility disorders. [source] Cell-free supernatants of Escherichia coli Nissle 1917 modulate human colonic motility: evidence from an in vitro organ bath studyNEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2009F. Bär Abstract, Clinical studies have shown that probiotics influence gastrointestinal motility, e.g. Escherichia coli Nissle 1917 (EcN) (Mutaflor®) proved to be at least as efficacious as lactulose and more potent than placebo in constipated patients. As the underlying mechanisms are not clarified, the effects of EcN culture supernatants on human colonic motility were assessed in vitro. Human colonic circular smooth muscle strips (n = 94, 17 patients) were isometrically examined in an organ bath and exposed to different concentrations of EcN supernatants. Contractility responses were recorded under (i) native conditions, (ii) electrical field stimulation (EFS), (iii) non-adrenergic non-cholinergic conditions, and (iv) enteric nerve blockade by tetrodotoxin (TTX). As concentrations of acetic acid were increased in EcN supernatants, contractility responses to acetic acid were additionally tested. EcN supernatants significantly increased the maximal tension forces both at low and high concentrations. Neither blockade of both adrenergic and cholinergic nerves nor application of TTX abolished these effects. EFS-induced contractility responses were not altered after exposure to EcN supernatants. Acetic acid elicited effects comparable to EcN supernatants only under TTX conditions. EcN supernatants modulate in vitro contractility of the human colon. As neither partial nor TTX blockade of enteric nerves abolished these effects, EcN supernatants appear to enhance colonic contractility by direct stimulation of smooth muscle cells. Active metabolites may include other substances than acetic acid, as acetic acid only partially resembled the effects elicited by EcN supernatants. The data provide a rationale for therapeutical application of probiotics in gastrointestinal motility disorders. [source] Analysis of gastrointestinal physiology using a novel intestinal transit assay in zebrafishNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2009H. A. Field Abstract, Gastrointestinal function depends upon coordinated contractions to mix and propel food through the gut. Deregulation of these contractions leads to alterations in the speed of material transit through the gut, with potentially significant consequences. We have developed a method for visualizing intestinal transit, the physiological result of peristaltic contractions, in larval zebrafish. This method allows direct, non-invasive observation of luminal content as it traverses the gut. Using this method, we characterized gastrointestinal transit in zebrafish larvae at 7 days postfertilization. In addition, we used this transit assay to assess the physiological consequences of reduced or absent enteric neurones on intestinal transit in larval zebrafish. This may facilitate the use of the zebrafish for investigating the effect of compounds and candidate genes on gastrointestinal motility. [source] Localization and gestation-dependent pattern of corticotrophin-releasing factor receptor subtypes in ovine fetal distal colonNEUROGASTROENTEROLOGY & MOTILITY, Issue 12 2008J. Lakshmanan Abstract, Meconium passage is frequently observed in association with feto-maternal stress factors such as hypoxia and infection, but the triggering mechanism is unknown. We hypothesize that differential regulation of corticotrophin-releasing factor (CRF) receptors during gestation play an important role in determining the susceptibilities of the fetus to stress-induced in utero meconium passage at term. We examined the innervation patterns of CRF-receptor type 1 (CRF-R1), a stimulator of gastrointestinal motility and CRF-receptor type II (CRF-R2), an inhibitor of gastrointestinal motility in ovine fetal distal colonic segments from very preterm to term gestation. Both CRF-R1 and CRF-R2 receptors were present in muscularis mucosa as well as in longitudinal and circular smooth muscle layers in fetal distal colonic segments at all gestational ages. Quantitative image analysis indicated a 42% increase in CRF-R1 receptor immunoreactivity in muscularis mucosa and a 30% in longitudinal smooth muscle layers from very preterm to term. In contrast, CRF-R2 receptor immunoreactivity in muscularis mucosa as well as in longitudinal and circular smooth muscle layers decreased by 38%, 55% and 51%, respectively, at term. The percentage of enteric ganglia and the number of enteric neurons expressing CRF-R1 receptors were high at term. Western blot analysis identified 235 and 50 kDa molecular species of CRF-R1 receptors and 37 and 28 kDa molecular species of CRF-R2 receptors. In summary, we speculate that downregulation of CRF-R2 receptor abundance with concurrent increases in CRF-R1 receptor levels in myenteric-smooth muscle unit with advancing gestation sensitizes the colonic motility responses to stressors. [source] Experimental pancreatitis disturbs gastrointestinal and colonic motility in mice: effect of the prokinetic agent tegaserodNEUROGASTROENTEROLOGY & MOTILITY, Issue 10 2007T. C. Seerden Abstract, Acute pancreatitis remains a potentially life-threatening disease associated with gastrointestinal motility disturbances. Prokinetic agents may be useful to overcome these motility disturbances. In this study, we investigated the effect of acute necrotizing pancreatitis (ANP) on gastrointestinal motility in female mice and evaluated the effect of tegaserod, a prokinetic 5-hydroxytryptamine-4 (5HT4) receptor agonist. ANP was induced by feeding mice a choline-deficient ethionine-supplemented diet during 72 h. In vivo intestinal motility was measured as the geometric centre (GC) of 25 glass beads 30-120-360 min after gavage. Colonic peristaltic activity was studied using a modified Trendelenburg set-up. ANP significantly decreased GC 30-120-360 min after bead gavage, associated with a significant increase of myeloperoxidase in the proximal small intestine and colon, but not in the stomach or distal small intestine. Tegaserod significantly ameliorated GC 360 min after bead gavage in control and pancreatitis mice. In isolated colonic segments, ANP significantly decreased the amplitude of peristaltic waves and increased the interval between peristaltic contractions. Tegaserod normalized the disturbed interval. In conclusion, ANP impairs gastric, small intestinal and colonic motility in mice. Tegaserod improves ANP-induced motility disturbances in vivo and in vitro, suggesting a therapeutic benefit of prokinetic 5HT4 receptor agonists in the treatment of pancreatitis-induced ileus. [source] Recent advances in understanding the role of serotonin in gastrointestinal motility and functional bowel disordersNEUROGASTROENTEROLOGY & MOTILITY, Issue 2007James J. Galligan First page of article [source] The peptide hormone xenin induces gallbladder contractions in conscious dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2007Y. Kamiyama Abstract, Xenin is a 25-amino acid peptide isolated from human gastric mucosa. The biological activities of xenin include modulating intestinal motility and affecting exocrine pancreatic secretion and gastric acid secretion. The physiological effect of xenin on the gastrointestinal tract, however, is incomplete. The objective of this study is to investigate the effects of xenin on the gastrointestinal tract motility of conscious dogs. Gastrointestinal tract and gallbladder contractions were monitored by chronically implanted force transducers. Synthetic xenin was injected intravenously during the interdigestive state with or without pretreatment with cholinergic blockers. The effects of xenin following cholecystectomy and truncal vagotomy were also investigated. Xenin induced gallbladder and jejunal contractions, although a dose-dependent response was shown only with gallbladder contractions. These effects were inhibited by pretreatment with cholinergic blockers, but were not enhanced by truncal vagotomy. The jejunal contractions were completely inhibited by cholecystectomy. The only direct effect of xenin in terms of gastrointestinal motility was to induce gallbladder contractions in conscious dogs. The neural pathway mediating xenin's action was cholinergic, but not the vagal. This novel finding indicates a new role of xenin. [source] Magnet Tracking: a new tool for in vivo studies of the rat gastrointestinal motilityNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006R. Guignet Abstract, Digestive motility was studied in the rat using a miniaturized version of the Magnet Tracking system which monitored the progression of a small magnetic pill through the entire digestive tract. The dynamics of movement was followed and three-dimensional (3-D) images of digestive tract were generated. After a retention period in the stomach and rapid passage through duodenum, the magnet progressed along the small intestine with gradually decreasing speed and longer stationary periods. It remained in the caecum for variable intervals. In the colon, periods of progress alternated with long quiescent periods. Gastric activity oscillated at 5,6 min,1. In the small intestine, two frequency domains coexisted, showing independent modulations and proximo-distal gradients (40 to >32 and 28 to >20 min,1). Caecal oscillations were of 1.5 min,1. The data allowed the magnet location and calculation of gastric and small intestinal transit times (58 ± 36 and 83 ± 14 min respectively), both significantly prolonged by oleate administration (243 ± 130 and 170 ± 45 min respectively). Magnet Tracking is a non-invasive tool to study the in vivo spatial and temporal organization of gastrointestinal motility in the rat. [source] Education project for pathophysiology of gastrointestinal motilityNEUROGASTROENTEROLOGY & MOTILITY, Issue 2005the varenna group No abstract is available for this article. [source] Effects of the herbal formulation ColiMil® on upper gastrointestinal transit in mice in vivoPHYTOTHERAPY RESEARCH, Issue 10 2007Raffaele Capasso Abstract Clinical evidence suggests that the herbal formulation ColiMil® (which contains Matricaria recutita flowers extract, Foeniculum vulgare fruit extract and Melissa officinalis aerial parts extract) is effective in the treatment of breastfed colic in infants. Therefore the effect of this phytotherapeutic formulation and its herbal constituents on upper gastrointestinal transit was investigated in mice in vivo. Oral administration of the herbal formulation (0.4,0.8 mL/mice) dose-dependently delayed upper gastrointestinal transit. Among the herbal components, Matricaria recutita extract (0.89 and 1.78 mg/mouse) and Melissa officinalis extract (6.46 and 12.92 mg/mouse), but not Foeniculum vulgare (8.21 and 16.42 mg/mouse), reduced motility significantly. These results suggest that ColiMil® reduces upper gastrointestinal motility in mice, with a major contribution by Matricaria recutita and Melissa officinalis. These experimental data may be important to better understand the observation that the herbal formulation ColiMil® improves colic in breastfed infants. Copyright © 2007 John Wiley & Sons, Ltd. [source] Smooth muscle contraction induced by Indigofera dendroides leaf extracts may involve calcium mobilization via potential sensitive channelsPHYTOTHERAPY RESEARCH, Issue 7 2003S. Amos Abstract The contractile effects of the aqueous extract of the leaves of Indigofera dendroides (ID) were studied on the gastrointestinal motility in mice and isolated smooth muscle preparations obtained from rats and guinea pigs. The contractile effects of 10,6 M acetylcholine, 80 mM KCl and 1.6 mg/ml ID were measured on the rat ileal smooth muscle exposed to calcium-free buffer or physiological solution, to determine the calcium pools mobilized by extract for activation of contraction. Acute toxicity test (LD50) was also carried out in mice. The result showed that ID (0.05,3.2 mg/ml) produced a concentration-dependent contraction of the guinea pig and rat ileum. These responses were not blocked by mepyramine (2.49 × 10,9 M), verapamil (8.14 × 10,9 M), or pirenzepine (4.7 × 10,7 M), but were blocked completely by atropine (2.92 × 10,9 M). A signi.cant increase in propulsion of gastrointestinal motility was observed. Acetylcholine, KCl and ID produced contractions in Ca2+ free media. The phasic components of the contractile responses to Ach as well as the tonic component of K+ and ID-induced contractions were relatively resistant to short periods of calcium-free exposure. Ach, K+ and ID still caused contractions in the presence of verapamil. The data revealed that ID-induced contractions were not mediated by histaminergic receptors, calcium channels, M1 muscarinic receptors. It also suggests that Ach mobilize Ca from some tightly bound or intracellular pool, whereas high K+ and ID may mobilize Ca from some superficial or loosely-bound pool. Copyright © 2003 John Wiley & Sons, Ltd. [source] Effects of female steroid hormones on A-type K+ currents in murine colonTHE JOURNAL OF PHYSIOLOGY, Issue 2 2006Elizabeth A. H. Beckett Idiopathic constipation is higher in women of reproductive age than postmenopausal women or men, suggesting that female steroid hormones influence gastrointestinal motility. How female hormones affect motility is unclear. Colonic motility is regulated by ion channels in colonic myocytes. Voltage-dependent K+ channels serve to set the excitability of colonic muscles. We investigated regulation of Kv4.3 channel expression in response to acute or chronic changes in female hormones. Patch clamp experiments and quantitative PCR were used to compare outward currents and transcript expression in colonic myocytes from male, non-pregnant, pregnant and ovariectomized mice. Groups of ovariectomized mice received injections of oestrogen or progesterone to investigate the effects of hormone replacement. The capacitance of colonic myocytes from non-pregnant females was larger than in males. Net outward current density in male and ovariectomized mice was higher than in non-pregnant females and oestrogen-treated ovariectomized mice. Current densities in late pregnancy were lower than in female controls. Progesterone had no effect on outward currents. A-type currents were decreased in non-pregnant females compared with ovariectomized mice, and were further decreased by pregnancy or oestrogen replacement. Kv4.3 transcripts did not differ significantly between groups; however, expression of the potassium channel interacting protein KChIP1 was elevated in ovariectomized mice compared with female controls and oestrogen-treated ovariectomized mice. Delayed rectifier currents were not affected by oestrogen. In the mouse colon, oestrogen suppresses A-type currents, which are important for regulating excitability. These observations suggest a possible link between female hormones and altered colonic motility associated with menses, pregnancy and menopause. [source] The role of carbon monoxide in the gastrointestinal tractTHE JOURNAL OF PHYSIOLOGY, Issue 2 2004Simon J. Gibbons Carbon monoxide (CO) is a biologically active product of haem metabolism that contributes to the normal physiology of the gastrointestinal tract. In this article, we review recent data showing that CO is an integral regulator of gastrointestinal motility and an important factor in the response to gastrointestinal injury. CO is generated by haem oxygenase-2 (HO-2), which is constitutively expressed in many inhibitory neurones of the vertebrate enteric nervous system. The membrane potential gradients along and across the muscle layers of the gastrointestinal tract require the generation of CO by haem oxygenase-2. The presence of CO is also necessary for normal inhibitory neurotransmission in circular smooth muscle and appears to permit nitric oxide-mediated inhibitory neurotransmission. Genetic deletion of the haem oxygenase-2 gene in mice slows gut transit. The other major CO synthetic enzyme, haem oxygenase-1 (HO-1) is induced under conditions of stress or injury. Recent studies have demonstrated that up-regulation of haem oxygenase-1 protects the gut from several types of gastrointestinal injury, suggesting that CO or induction of HO-1 may find therapeutic use in gastrointestinal diseases and injuries. Furthermore, it is anticipated that the understanding of CO-mediated signalling in the gastrointestinal tract will inform studies in other tissues that express haem oxygenases. [source] | ||||||||||||||||||||||||||||