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Data are limited regarding gastrointestinal motility disturbance in disorders of gut-brain interaction (DGBI). This study aimed to characterize antroduodenal motor alterations in patients with high-resolution antroduodenal manometry (HR-ADM). HR-ADM was performed in patients with severe DGBI and compared with healthy volunteers (HV). HR-ADM used a commercially available probe composed of 36 electronic sensors spaced 1 cm apart and positioned across the pylorus. Antral and duodenal motor high-resolution profiles were analyzed, based on the frequency, amplitude, and contractile integral/sensor (CI/s) calculated for each phase of the migrating motor complex (MMC). Eighteen HV and 64 patients were investigated, 10 with irritable bowel syndrome (IBS), 24 with functional dyspepsia (FD), 15 with overlap IBS-FD, and 15 with other DGBI. Compared with HV, patients had a lower frequency of phase II duodenal contractions (27 vs. 51 per hour; P = 0.002) and a lower duodenal phase II contraction amplitude (70 vs. 100 mmHg; P = 0.01), resulting in a lower CI/s of phase II (833 vs. 1,901 mmHg·cm·s; P < 0.001) in the duodenum. In addition, the frequency of phase II propagated antroduodenal contractions was lower (5 vs. 11 per hour; P < 0.001) in patients compared with HV. Interestingly, the antral CI/s of phase III was decreased in FD patients but not in IBS patients. Patients with severe DGBI display alterations in antral and intestinal motility assessed by commercially available HR-ADM. Whether these alterations may explain symptom profiles in such patients remains to be confirmed (NCT04918329 and NCT01519180).NEW & NOTEWORTHY Gastrointestinal dysmotility has been assessed poorly in disorders of gut-brain interaction (DGBI), especially with high-resolution antroduodenal manometry. Plots of DGBI patients showed lower duodenal contractions during phase II regarding amplitude, frequency, and contractile integral/sensor (CI/s) compared with healthy volunteers. A lower frequency of propagated antroduodenal contractions was also reported. Finally, antral CI/s was lower in patients with functional dyspepsia during phase III. Further studies are needed to assess the clinical significance of these alterations.
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Duodeno , Motilidad Gastrointestinal , Manometría , Antro Pilórico , Humanos , Manometría/métodos , Masculino , Femenino , Adulto , Motilidad Gastrointestinal/fisiología , Persona de Mediana Edad , Duodeno/fisiopatología , Antro Pilórico/fisiopatología , Dispepsia/fisiopatología , Síndrome del Colon Irritable/fisiopatología , Anciano , Complejo Mioeléctrico Migratorio/fisiología , Estudios de Casos y Controles , Contracción MuscularRESUMEN
BACKGROUND: Gastric myoelectric signals have been the focus of extensive research; although it is unclear how general anesthesia affects these signals, and studies have often been conducted under general anesthesia. Here, we explore this issue directly by recording gastric myoelectric signals during awake and anesthetized states in the ferret and explore the contribution of behavioral movement to observed changes in signal power. METHODS: Ferrets were surgically implanted with electrodes to record gastric myoelectric activity from the serosal surface of the stomach, and, following recovery, were tested in awake and isoflurane-anesthetized conditions. Video recordings were also analyzed during awake experiments to compare myoelectric activity during behavioral movement and rest. KEY RESULTS: A significant decrease in gastric myoelectric signal power was detected under isoflurane anesthesia compared to the awake condition. Moreover, a detailed analysis of the awake recordings indicates that behavioral movement is associated with increased signal power compared to rest. CONCLUSIONS & INFERENCES: These results suggest that both general anesthesia and behavioral movement can affect the signal power of gastric myoelectric recordings. In summary, caution should be taken in studying myoelectric data collected under anesthesia. Further, behavioral movement could have an important modulatory role on these signals, affecting their interpretation in clinical settings.
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Anestesia , Isoflurano , Animales , Isoflurano/farmacología , Hurones , Estómago , Electrodos , Complejo Mioeléctrico MigratorioRESUMEN
Motilin is an important hormonal regulator in the migrating motor complex (MMC). Free fatty acid receptor-1 (FFAR1, also known as GPR40) has been reported to stimulate motilin release in human duodenal organoids. However, how FFAR1 regulates gastric motility in vivo is unclear. This study investigated the role of FFAR1 in the regulation of gastric contractions and its possible mechanism of action using Suncus murinus. Firstly, intragastric administration of oleic acid (C18:1, OA), a natural ligand for FFAR1, stimulated phase II-like contractions, followed by phase III-like contractions in the fasted state, and the gastric emptying rate was accelerated. The administration of GW1100, an FFAR1 antagonist, inhibited the effects of OA-induced gastric contractions. Intravenous infusion of a ghrelin receptor antagonist (DLS) or serotonin 4 (5-HT4) receptor antagonist (GR125487) inhibited phase II-like contractions and prolonged the onset of phase III-like contractions induced by OA. MA-2029, a motilin receptor antagonist, delayed the occurrence of phase III-like contractions. In vagotomized suncus, OA did not induce phase II-like contractions. In addition, OA promoted gastric emptying through a vagal pathway during the postprandial period. However, OA did not directly act on the gastric body to induce contractions in vitro. In summary, this study indicates that ghrelin, motilin, 5-HT, and the vagus nerve are involved in the role of FFAR1 regulating MMC. Our findings provide novel evidence for the involvement of nutritional factors in the regulation of gastric motility.
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Ácidos Grasos no Esterificados , Motilidad Gastrointestinal , Humanos , Animales , Ácidos Grasos no Esterificados/farmacología , Motilina/metabolismo , Motilina/farmacología , Complejo Mioeléctrico Migratorio/fisiología , Estómago/fisiología , Musarañas/metabolismoRESUMEN
In a fasting gastrointestinal tract, a characteristic cyclical rhythmic migrating motor complex (MMC) occur that comprises of three phases: I, II, and III. Among these, phase III contractions propagate from the stomach to the lower intestine in mammals, including humans, dogs, and Suncus murinus (suncus). Apart from the phase III of MMC propagating from the stomach, during the gastric phase II, small intestine-originated strong contractions propagate to the lower small intestine; however, the mechanism of contractions originating in the small intestine has not been clarified. In this study, we aimed to elucidate the role of cholecystokinin (CCK) in small intestinal motility. Administration of sulfated CCK-8 in phase I induced phase II-like contractions in the small intestine, which lasted for approximately 10-20 min and then returned to the baseline, while no change was observed in the stomach. Contractions of small intestine induced by CCK-8 were abolished by lorglumide, a CCK1 receptor antagonist. Gastrin, a ligand for the CCK2 receptor, evoked strong contractions in the stomach, but did not induce contractions in the small intestine. To examine the effect of endogenous CCK on contractions of small intestinal origin, lorglumide was administered during phase II. However, there was no change in the duodenal motility pattern, and strong contractions of small intestinal origin were not abolished by treatment with lorglumide. These results suggest that exogenous CCK stimulates contractions of small intestine via CCK1 receptors, whereas endogenous CCK is not involved in the strong contractions of small intestinal origin.
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Motilidad Gastrointestinal , Sincalida , Humanos , Animales , Perros , Sincalida/farmacología , Complejo Mioeléctrico Migratorio/fisiología , Colecistoquinina/farmacología , Estómago , Musarañas , Receptores de ColecistoquininaRESUMEN
BACKGROUND: Little is known about ileal motility patterns and their utility in children. Here, we present our experience with children undergoing ileal manometry (IM). METHODS: A retrospective review of children with ileostomy comparing IM between 2 groups: A [chronic intestinal pseudo-obstruction (CIPO)] and B (feasibility of ileostomy closure in children with defecation disorders). We also compared the IM findings with those from antroduodenal manometry (ADM), and evaluated the joint effect of age, sex, and study indication group on IM results. RESULTS: A total of 27 children (median age 5.8 years old, range 0.5-16.74 years, 16 were female) were included (12 in group A and 15 in group B). There was no association between IM interpretation and sex; however younger age was associated with abnormal IM ( P = 0.021). We found a significantly higher proportion of patients with presence of phase III of the migrating motor complex (MMC) during fasting and normal postprandial response in group B than in group A ( P < 0.001). Logistic regression analysis revealed that only Group B was associated with normal IM ( P < 0.001). We found a moderate agreement for the presence of phase III MMC and postprandial response between IM and ADM (kappa = 0.698, P = 0.008 and kappa = 0.683, P = 0.009, respectively). CONCLUSION: IM is abnormal in patients with CIPO and normal in patients with defecation disorders, suggesting that IM may be not needed for ostomy closure in those with defecation disorders. IM has a moderate agreement with ADM and could be used as a surrogate for small bowel motility.
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Defecación , Seudoobstrucción Intestinal , Niño , Humanos , Femenino , Lactante , Preescolar , Adolescente , Masculino , Seudoobstrucción Intestinal/diagnóstico , Seudoobstrucción Intestinal/cirugía , Motilidad Gastrointestinal/fisiología , Complejo Mioeléctrico Migratorio/fisiología , Intestino Delgado , Enfermedad Crónica , Manometría/métodosRESUMEN
Motilin is a gastrointestinal hormone secreted by the duodenum. This peptide regulates a characteristic gastrointestinal contraction pattern, called the migrating motor complex, during the fasting state. Motilin also affects the pressure of the lower esophageal sphincter, gastric motility and gastric accommodation in the gastrointestinal tract. Furthermore, motilin induces bile discharge into the duodenum by promoting gallbladder contraction, pepsin secretion in the stomach, pancreatic juice and insulin secretion from the pancreas. In recent years, it has been shown that motilin is associated with appetite, and clinical applications are expected for diseases affected by food intake, e.g. obesity, by regulating motilin levels. Gastric acid and bile are the two major physiological regulators for motilin release. Caloric foods have varying effects on motilin levels, depending on their composition. Among non-caloric foods, bitter substances reduce motilin levels and are therefore expected to have an appetite-suppressing effect. Various motilin receptor agonists and antagonists have been developed but have yet to reach clinical use.
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Hormonas Gastrointestinales , Motilina , Motilidad Gastrointestinal/fisiología , Estómago , Hormonas Gastrointestinales/farmacología , Complejo Mioeléctrico Migratorio/fisiología , DuodenoRESUMEN
BACKGROUND: Gastroparesis (GP) is a gastrointestinal disorder associated with significant morbidity and healthcare costs. GP patients form a heterogeneous population with diverse etiology, and treatment is often challenging due to a poorly understood underlying pathophysiology. The aim of the present study was to assess antroduodenal motility patterns among the different GP etiologies. METHODS: We reviewed antroduodenal manometry (ADM) recordings of patients with confirmed GP between 2009 and 2019. ADM measurements were evaluated for fed period duration, number of phase III contractions and migrating motor complexes (MMCs), motility index (MI), and presence of neuropathic patterns. KEY RESULTS: A total of 167 GP patients (142 women, median age 45 [31-57]) were included. The following etiologies were identified: idiopathic n = 101; post-surgery n = 36; and diabetes n = 30. Fed period duration was significantly longer in idiopathic (p < 0.01) and diabetic GP patients (p < 0.05) compared with post-surgery GP patients. Furthermore, the number and duration of phase III contractions and the number of MMCs were significantly lower in idiopathic and diabetic patients compared with post-surgery GP patients (p < 0.01). Likewise, absence of MMCs during 6-h recording was more often observed in idiopathic and diabetes GP patients compared with post-surgery GP patients (resp. p < 0.01 and p < 0.05). CONCLUSIONS AND INFERENCES: Antroduodenal motility patterns are different among GP etiologies. A dysmotility spectrum was identified with different patterns ranging from post-surgery GP to idiopathic and diabetic GP.
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Neuropatías Diabéticas , Gastroparesia , Duodeno/fisiología , Femenino , Motilidad Gastrointestinal/fisiología , Gastroparesia/diagnóstico , Gastroparesia/etiología , Humanos , Manometría , Persona de Mediana Edad , Complejo Mioeléctrico Migratorio/fisiologíaRESUMEN
BACKGROUND/OBJECTIVES: Gastric emptying (GE) requires precise antropyloroduodenal coordination for effective transpyloric flow, the mechanisms of which are still unclear. We aimed to correlate gastric antral function assessed by antroduodenal manometry (ADM) with GE scintigraphy (GES) for liquid feeds in children with suspected gastrointestinal dysmotility. METHODS: Children who underwent both ADM and GES over a five-year period were reviewed. ADM tracings were re-analyzed to assess antral frequency, amplitude, and motility index (MI) pre-prandially and postprandially. Transpyloric propagation (TPP) was defined as antegrade propagated antral activity preceding duodenal phase III of the migrating motor complex (MMC). TPP was defined as "poor" if occurring in <50% of all presented duodenal phases III. For GES, regions of interest over the whole stomach, fundus, and antrum were drawn to calculate GE half-time (GE-T1/2 ) and retention rate (RR) in each region at 1 and 2 h. RESULTS: Forty-seven children (median age: 7.0 years) were included. Twenty-two had PIPO, 14 functional GI disorders, and 11 gastroparesis. Children with poor TPP had longer GE-T1/2 (113.0 vs 66.5 min, p = 0.028), higher RR of the whole stomach and fundus at 1 h (79.5% vs 63.5%, p = 0.038; 60.0% vs 41.0%, p = 0.022, respectively) and 2 h (51.0% vs 10.5%, p = 0.005; 36.0% vs 6.5%, p = 0.004, respectively). The pre-prandial antral amplitude of contractions inversely correlated with GE-T1/2 , RR of the whole stomach, and fundus at 2 h. CONCLUSIONS: TPP during phase III of the MMC correlated with gastric emptying of liquid and its assessment on ADM might predict abnormalities in postprandial gastric function.
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Vaciamiento Gástrico , Gastroparesia , Niño , Duodeno , Motilidad Gastrointestinal , Humanos , Manometría , Complejo Mioeléctrico Migratorio , Antro PilóricoRESUMEN
RESUMEN: El objetivo de este estudio fue determinar el efecto de la práctica mental kinestésica (PMK) en la fuerza y actividad eléctrica muscular (AEM) del bíceps braquial, luego de un periodo de inmovilización del codo en un grupo de personas adultos jóvenes sanos. Un total de 14 personas (18,64 ± 0,92 años de edad) participaron voluntariamente del estudio, a las cuales se les evaluó la fuerza muscular de prensión y la AEM del bíceps braquial utilizando un dinamómetro de mano y un equipo de electromiografía, respectivamente, antes y después de un periodo de inmovilización del brazo no dominante, y se asignaron aleatoriamente a uno de dos grupos: grupo control (GC) o experimental (GE). El GE realizó PMK: tres series de 15 repeticiones con un minuto de descanso entre series, tres veces al día durante los seis días de inmovilización, mientras que el GC no realizó PKM durante su inmovilización. Al aplicar una prueba de ANOVA de dos vías, no se encontraron diferencias significativas en la fuerza ni en la AEM. Sin embargo, la fuerza del GC disminuyó en 23,75%, mientras que la del GE aumentó en 33,19%. Los resultados sugieren que un periodo de inmovilización del codo de seis días no fue suficiente para que la fuerza ni la AEM disminuyan significativamente, lo que supone que la PMK realizada no es necesaria en periodos menores a seis días.
ABSTRACT: The aim of this study was to determine the effect of kinesthetic mental practice (KMP) on the strength and muscular electrical activity (MEA) of the brachial biceps, after a period of immobilization of the elbow in a group of healthy young adults. A total of 14 volunteer participants (18.64 ± 0.92 years of age) were part in the study. The muscle strength and the AEM of the brachial biceps were assessed using a hand dynamometer and an electromyography equipment, respectively, before and after a period of immobilization of the non-dominant arm. After the pretest, they were randomly assigned to one of two groups: control group (GC) or experimental group (GE). The GE performed 3 sets of 15 repetitions with one-minute rest between sets, three times a day of PMK during the 6 days of immobilization, while the GC did not perform PKM during its immobilization. A 2-way ANOVA test (group x measurement) indicated non-significant differences in strength or AEM. However, the strength of the GC decreased by 23.75%, while increased by 33.19% in the GE. The results suggest that a period of immobilization of the elbow of 6 days was not enough for the strength or the AEM to decrease significantly, which means that the PMK is not necessary in periods of immobilization of less than 6 days.
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Humanos , Masculino , Femenino , Adolescente , Adulto , Adulto Joven , Complejo Mioeléctrico Migratorio , Codo/anomalías , Cinésica , Electromiografía/métodos , Fuerza Muscular/fisiología , Dinamómetro de Fuerza Muscular/tendenciasRESUMEN
Gastric distension is known to affect normal slow-wave activity and gastric function, but links between slow-wave dysrhythmias and stomach function are poorly understood. Low-resolution mapping is unable to capture complex spatial properties of gastric dysrhythmias, necessitating the use of high-resolution mapping techniques. Characterizing the nature of these dysrhythmias has implications in the understanding of postprandial function and the development of new mapping devices. In this two-phase study, we developed and implemented a protocol for measuring electrophysiological responses to gastric distension in porcine experiments. In vivo, serosal high-resolution electrical mapping (256 electrodes; 36 cm2) was performed in anaesthetized pigs (n = 11), and slow-wave pattern, velocity, frequency, and amplitude were quantified before, during, and after intragastric distension. Phase I experiments (n = 6) focused on developing and refining the distension mapping methods using a surgically inserted intragastric balloon, with a variety of balloon types and distension protocols. Phase II experiments (n = 5) used barostat-controlled 500-mL isovolumetric distensions of an endoscopically introduced intragastric balloon. Dysrhythmias were consistently induced in all five gastric distensions, using refined distension protocols. Dysrhythmias appeared 23 s (SD = 5 s) after the distension and lasted 129 s (SD = 72 s), which consisted of ectopic propagation originating from the greater curvature in the region of distension. In summary, our results suggest that distension disrupts gastric entrainment, inducing temporary ectopic slow-wave propagation. These results may influence the understanding of the postprandial stomach and electrophysiological effects of gastric interventions.NEW & NOTEWORTHY This study presents the discovery of temporary dysrhythmic ectopic pacemakers in the distal stomach caused by localized gastric distension. Distension-induced dysrhythmias are an interesting physiological phenomenon that can inform the design of new interventional and electrophysiological protocols for both research and the clinic. The observation of distension-induced dysrhythmias also contributes to our understanding of stretch-sensitivity in the gut and may play an important role in normal and abnormal postprandial physiology.
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Relojes Biológicos , Células Intersticiales de Cajal/fisiología , Complejo Mioeléctrico Migratorio , Estómago/fisiología , Animales , Femenino , Balón Gástrico , Sus scrofa , Factores de TiempoRESUMEN
Soft faecal material is transformed into discrete, pellet-shaped faeces at the colonic flexure. Here, analysis of water content in natural faecal material revealed a decline from cecum to rectum without significant changes at the flexure. Thus, pellet formation is not explained by changes in viscosity alone. We then used video imaging of colonic wall movements with electromyography in isolated preparations containing guinea-pig proximal colon, colonic flexure and distal colon. To investigate the pellet formation process, the colonic segments were infused with artificial contents (Krebs solution and 4-6% methylcellulose) to simulate physiological faecal content flow. Remarkably, pellet formation took place in vitro, without extrinsic neural inputs. Infusion evoked slowly propagating neurogenic contractions, the proximal colon migrating motor complexes (â¼0.6 cpm), which initiated pellet formation at the flexure. Lesion of the flexure, but not the proximal colon, disrupted the formation of normal individual pellets. In addition, a distinct myogenic mechanism was identified, whereby slow phasic contractions (â¼1.9 cpm) initiated at the flexure and propagated short distances retrogradely into the proximal colon and antegradely into the distal colon. There were no detectable changes in the density or distribution of pacemaker-type interstitial cells of Cajal across the flexure. The findings provide new insights into how solid faecal content is generated, suggesting the major mechanisms underlying faecal pellet formation involve the unique interaction at the colonic flexure between antegrade proximal colon migrating motor complexes, organized by enteric neurons, and retrograde myogenic slow phasic contractions. Additional, as yet unidentified extrinsic and/or humoral influences appear to contribute to processing of faecal content in vivo. KEY POINTS: In herbivores, including guinea-pigs, clearly defined faecal pellets are formed at a distinct location along the large intestine (colonic flexure). The mechanism underlying the formation of these faecal pellets at this region has remained unknown. We reveal a progressive and gradual reduction in water content of faecal content along the bowel. Hence, the distinct transition from amorphous to pellet shaped faecal content could not be explained by a dramatic increase in water reabsorption from a specific site. We discovered patterns of anterograde neurogenic and retrograde myogenic motor activity that facilitate the formation of faecal pellets. The formation of 'pellet-like' boluses at the colonic flexure involves interaction of an antegrade migrating motor complex in the proximal colon and retrograde myogenic slow phasic contractions that emerge from the colonic flexure. The findings uncover intrinsic mechanisms responsible for the formation of discrete faecal scybala in the large intestine of a vertebrate.
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Motilidad Gastrointestinal , Complejo Mioeléctrico Migratorio , Animales , Colon , Heces , Cobayas , Intestino GruesoRESUMEN
BACKGROUND: The manometric diagnosis of severe intestinal dysmotility is performed at most institutions using catheters with 2-8 sensors 5-10 cm apart. The recent application of high-resolution manometry catheters with closely spaced sensors to other gut segments has been highly successful. The objective of the present study was to determine the feasibility of a jejunal high-resolution manometry method and to carry out a descriptive analysis of normal jejunal motor function. METHODS: A 36-channel high-resolution water-perfused manometry catheter (MMS-Laborie, Enschede, The Netherlands) was orally placed in the jejunum of 18 healthy subjects (10 men, eight women; 21-38 age range). Intestinal motility was recorded during 5 h, 3 during fasting, and 2 after a 450 kcal solid-liquid meal. Analysis of motility patterns was supported by computerized tools. KEY RESULTS: All healthy subjects except one showed at least one complete migrating motor complex during the 3 h fasting period. Phase III activity lasted 5 ± 1 min and migrated aborally at a velocity of 7 ± 3 cm/min. High-resolution spatial analysis showed that during phase III each individual contraction propagated rapidly (75 ± 37 cm/min) over a 32 ± 10 cm segment of the jejunum. During phase II, most contractile activity corresponded to propagated contractile events which increased in frequency from early to late phase II (0.5 ± 0.9 vs 2.5 ± 1.3 events/10 min, respectively; p < 0.001). After meal ingestion, non-propagated activity increased, whereas propagated events were less frequent than during late phase II. CONCLUSIONS & INFERENCES: Jejunal motility analysis with high-resolution manometry identifies propagated contractile patterns which are not apparent with conventional manometric catheters.
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Ingestión de Alimentos/fisiología , Yeyuno/fisiología , Complejo Mioeléctrico Migratorio/fisiología , Adulto , Ayuno/fisiología , Femenino , Humanos , Masculino , Manometría , Estudios Prospectivos , Agua , Adulto JovenRESUMEN
OBJECTIVES: Antroduodenal manometry (ADM) is used to evaluate antral and small intestinal motility, with the presence of phase III migrating motor complexes (MMCs) indicating an intact enteric neuromuscular system. The lack of evidence-based or consensus-driven established norms for MMC in fasting phase and after provocative testing marks a major limitation in the interpretation of ADM studies. We aimed to determine the characteristics of MMC in fasting and post-provocative phase in children. METHODS: Data from subjects ages <20âyears with ADM results evaluated at neuro-gastroenterology and Motility Disorders Center, Cincinnati Children's Hospital Medical Center from January 2018 to March 2019 were analyzed. RESULTS: Forty-eight ADM tracings that did not demonstrate abnormal patterns were included; the mean age was 10.00â±â5.72âyears and 50% were male. Indications for ADM included: vomiting (27.1%), feeding intolerance (27.1%), abdominal pain (16.6%), nausea (14.6%), and abdominal distension (14.6%). Thirty-seven percent of subjects had enteral access for feeds. During fasting, one-third of all MMC originated in the antrum. Azithromycin-induced MMC occurred in 28% of subjects and two-thirds of these originated in the antrum with antral contractions of significantly higher frequency and amplitude compared to fasting. Octreotide significantly increased frequency, amplitude, and duration of MMC compared to fasting, with 76% originating in the antrum. Both azithromycin and octreotide induced more than one MMC in a third of subjects. CONCLUSIONS: We describe the characteristics of antral and small intestinal motility during fasting and after provocative testing in children. These values will help standardize our interpretation of pediatric ADM studies.
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Motilidad Gastrointestinal , Complejo Mioeléctrico Migratorio , Adolescente , Adulto , Niño , Preescolar , Duodeno , Ayuno , Humanos , Intestino Delgado , Masculino , Manometría , Adulto JovenRESUMEN
BACKGROUND: Different peripheral pathways are implicated in the regulation of the food ingestion-digestion cycle. METHODS: Narrative review on gastrointestinal mechanisms involved in satiety and hunger signalling. RESULTS: Combined mechano- and chemoreceptors, peripherally released peptide hormones and neural pathways provide feedback to the brain to determine sensations of hunger (increase energy intake) or satiation (cessation of energy intake) and regulate the human metabolism. The gastric accommodation reflex, which consists of a transient relaxation of the proximal stomach during food intake, has been identified as a major determinant of meal volume, through activation of tension-sensitive gastric mechanoreceptors. Motilin, whose release is the trigger of gastric Phase 3, has been identified as the major determinant of return of hunger after a meal. In addition, the release of several peptide hormones such as glucagon-like peptide 1 (GLP-1), cholecystokinin as well as motilin and ghrelin contributes to gut-brain signalling with relevance to control of hunger and satiety. A number of nutrients, such as bitter tastants, as well as pharmacological agents, such as endocannabinoid receptor antagonists and GLP-1 analogues act on these pathways to influence hunger, satiation and food intake. CONCLUSION: Gastrointestinal mechanisms such as gastric accommodation and motilin release are key determinants of satiety and hunger.
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Tracto Gastrointestinal/fisiología , Hambre/fisiología , Saciedad/fisiología , Animales , Colecistoquinina/sangre , Ghrelina/sangre , Péptido 1 Similar al Glucagón , Humanos , Motilina/sangre , Complejo Mioeléctrico Migratorio , GustoRESUMEN
BACKGROUND & AIMS: Constipation is commonly associated with diabetes. Serotonin (5-HT), produced predominantly by enterochromaffin (EC) cells via tryptophan hydroxylase 1 (TPH1), is a key modulator of gastrointestinal (GI) motility. However, the role of serotonergic signaling in constipation associated with diabetes is unknown. METHODS: We generated EC cell reporter Tph1-tdTom, EC cell-depleted Tph1-DTA, combined Tph1-tdTom-DTA, and interstitial cell of Cajal (ICC)-specific Kit-GCaMP6 mice. Male mice and surgically ovariectomized female mice were fed a high-fat high-sucrose diet to induce diabetes. The effect of serotonergic signaling on GI motility was studied by examining 5-HT receptor expression in the colon and in vivo GI transit, colonic migrating motor complexes (CMMCs), and calcium imaging in mice treated with either a 5-HT2B receptor (HTR2B) antagonist or agonist. RESULTS: Colonic transit was delayed in males with diabetes, although colonic Tph1+ cell density and 5-HT levels were increased. Colonic transit was not further reduced in diabetic mice by EC cell depletion. The HTR2B protein, predominantly expressed by colonic ICCs, was markedly decreased in the colonic muscles of males and ovariectomized females with diabetes. Ca2+ activity in colonic ICCs was decreased in diabetic males. Treatment with an HTR2B antagonist impaired CMMCs and colonic motility in healthy males, whereas treatment with an HTR2B agonist improved CMMCs and colonic motility in males with diabetes. Colonic transit in ovariectomized females with diabetes was also improved significantly by the HTR2B agonist treatment. CONCLUSIONS: Impaired colonic motility in mice with diabetes was improved by enhancing HTR2B signaling. The HTR2B agonist may provide therapeutic benefits for constipation associated with diabetes.
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Colon/efectos de los fármacos , Estreñimiento/prevención & control , Complicaciones de la Diabetes/prevención & control , Motilidad Gastrointestinal/efectos de los fármacos , Indoles/farmacología , Células Intersticiales de Cajal/efectos de los fármacos , Complejo Mioeléctrico Migratorio/efectos de los fármacos , Receptor de Serotonina 5-HT2B/efectos de los fármacos , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Tiofenos/farmacología , Animales , Señalización del Calcio , Colon/metabolismo , Colon/fisiopatología , Estreñimiento/etiología , Estreñimiento/metabolismo , Estreñimiento/fisiopatología , Complicaciones de la Diabetes/metabolismo , Complicaciones de la Diabetes/fisiopatología , Modelos Animales de Enfermedad , Femenino , Genes Reporteros , Células Intersticiales de Cajal/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Ovariectomía , Proteínas Proto-Oncogénicas c-kit/genética , Proteínas Proto-Oncogénicas c-kit/metabolismo , Receptor de Serotonina 5-HT2B/metabolismo , Serotonina/metabolismo , Triptófano Hidroxilasa/genética , Triptófano Hidroxilasa/metabolismoRESUMEN
Gastrointestinal side effects of donepezil, including dyspepsia, nausea, vomiting or diarrhea, occur in 20-30% of patients. The pathogenesis of these dysmotility associated disorders has not been fully clarified yet. Pharmacokinetic parameters of donepezil and its active metabolite 6-O-desmethyldonepezil were investigated in experimental pigs with and without small intestinal injury induced by dextran sodium sulfate (DSS). Morphological features of this injury were evaluated by a video capsule endoscopy. The effect of a single and repeated doses of donepezil on gastric myoelectric activity was assessed. Both DSS-induced small intestinal injury and prolonged small intestinal transit time caused higher plasma concentrations of donepezil in experimental pigs. This has an important implication for clinical practice in humans, with a need to reduce doses of the drug if an underlying gastrointestinal disease is present. Donepezil had an undesirable impact on porcine myoelectric activity. This effect was further aggravated by DSS-induced small intestinal injury. These findings can explain donepezil-associated dyspepsia in humans.
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Donepezilo/farmacocinética , Tracto Gastrointestinal/patología , Tracto Gastrointestinal/fisiopatología , Indanos/metabolismo , Metaboloma , Complejo Mioeléctrico Migratorio , Piperidinas/metabolismo , Estómago/fisiopatología , Animales , Endoscopía Capsular , Sulfato de Dextran , Donepezilo/química , Donepezilo/farmacología , Femenino , Tracto Gastrointestinal/efectos de los fármacos , Metaboloma/efectos de los fármacos , Complejo Mioeléctrico Migratorio/efectos de los fármacos , Estómago/efectos de los fármacos , PorcinosRESUMEN
Electrical stimulation of the enteric nervous system (ENS) is an attractive approach to modify gastrointestinal transit. Colonic motor complexes (CMCs) occur with a periodic rhythm, but the ability to elicit a premature CMC depends, at least in part, upon the intrinsic refractory properties of the ENS, which are presently unknown. The objectives of this study were to record myoelectric complexes (MCs, the electrical correlates of CMCs) in the smooth muscle and 1) determine the refractory periods of MCs, 2) inform and evaluate closed-loop stimulation to repetitively evoke MCs, and 3) identify stimulation methods to suppress MC propagation. We dissected the colon from male and female C57BL/6 mice, preserving the integrity of intrinsic circuitry while removing the extrinsic nerves, and measured properties of spontaneous and evoked MCs in vitro. Hexamethonium abolished spontaneous and evoked MCs, confirming the necessary involvement of the ENS for electrically evoked MCs. Electrical stimulation reduced the mean interval between evoked and spontaneous CMCs (24.6 ± 3.5 vs. 70.6 ± 15.7 s, P = 0.0002, n = 7). The absolute refractory period was 4.3 s (95% confidence interval (CI) = 2.8-5.7 s, R2 = 0.7315, n = 8). Electrical stimulation applied during fluid distention-evoked MCs led to an arrest of MC propagation, and following stimulation, MC propagation resumed at an increased velocity (n = 9). The timing parameters of electrical stimulation increased the rate of evoked MCs and the duration of entrainment of MCs, and the refractory period provides insight into timing considerations for designing neuromodulation strategies to treat colonic dysmotility.NEW & NOTEWORTHY Maintained physiological distension of the isolated mouse colon induces rhythmic cyclic myoelectric complexes (MCs). MCs evoked repeatedly by closed-loop electrical stimulation entrain MCs more frequently than spontaneously occurring MCs. Electrical stimulation delivered at the onset of a contraction temporarily suppresses the propagation of MC contractions. Controlled electrical stimulation can either evoke MCs or temporarily delay MCs in the isolated mouse colon, depending on timing relative to ongoing activity.
Asunto(s)
Colon/inervación , Terapia por Estimulación Eléctrica , Sistema Nervioso Entérico/fisiología , Tránsito Gastrointestinal , Músculo Liso/inervación , Complejo Mioeléctrico Migratorio , Animales , Femenino , Masculino , Mecanotransducción Celular , Ratones Endogámicos C57BL , Presión , Periodo Refractario Electrofisiológico , Factores de TiempoRESUMEN
BACKGROUND: Age-associated changes alter calcium-activated potassium channel (BKCa ) expression of colon. Sphingolipids (SLs) are important cell membrane structural components; altered composition of SLs may affect BKCa expression. This study investigated the mechanism by which sphingosine-1-phosphate (S1P) contributes to age-associated contractile dysfunction. METHODS: Fifty male Sprague Dawley rats of different ages were randomly assigned to five age-groups, namely 3, 6, 12, 18, and 24 months. BKCa expression, S1P levels, and phosphorylated myosin light chain (p-MLC) levels were tested in colonic tissues. In the absence and presence of S1P treatment, BKCa expression, p-MLC levels, and intracellular calcium mobilization were tested in vitro. BKCa small interfering RNA (siRNA) was used to investigate whether p-MLC expression and calcium mobilization were affected by BKCa in colonic smooth muscle cells (SMCs). The expressions of phosphorylated protein kinase B, c-Jun N-terminal kinases (JNKs), extracellular-regulated protein kinases, nuclear factor kappa-B (NF-κB), and protein kinase Cζ (PKCζ ) were examined to investigate the correlation between S1P and BKCa . KEY RESULTS: Sphingosine-1-phosphate levels and sphingosine-1-phosphate receptor 2 (S1PR2) and BKCa expressions were upregulated and p-MLC expression was downregulated in the colonic tissues, age dependently. In the cultured SMCs, S1P treatment increased BKCa expression and reduced calcium concentration and p-MLC was observed. BKCa siRNA increased calcium concentration, and p-MLC levels significantly compared with control. We also showed that S1P upregulated BKCa through PKCζ , JNK, and NF-κB pathways. CONCLUSIONS AND INFERENCES: In conclusion, S1P and S1PR2 participate in age-associated contractile dysfunction via BKCa upregulation through PKCζ , JNK, and NF-κB pathways.
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Envejecimiento/metabolismo , Colon/metabolismo , Motilidad Gastrointestinal/fisiología , Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio/metabolismo , Lisofosfolípidos/metabolismo , Miocitos del Músculo Liso/metabolismo , Receptores de Esfingosina-1-Fosfato/metabolismo , Esfingosina/análogos & derivados , Envejecimiento/fisiología , Animales , Colon/fisiopatología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Técnicas de Silenciamiento del Gen , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Contracción Muscular/fisiología , Miocitos del Músculo Liso/fisiología , Complejo Mioeléctrico Migratorio/fisiología , Cadenas Ligeras de Miosina/metabolismo , FN-kappa B/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Interferente Pequeño , Ratas , Esfingosina/metabolismo , Regulación hacia ArribaRESUMEN
The demerit of pylorus-preserving gastrectomy(PPG)is the postprandial abdominal fullness(PAF)with gastric stasis in the remnant stomach(GSRS). We investigated the relationship between clinical findings and GSRS, and between GSRS and interdigestive migrating motor complex(IMMC)in PPG patients. A total of 30 patients(17 men and 13 women, mean age of 62.3 years)after PPG for early gastric cancer(Billroth â )were divided into 2 groups(group A; 18 patients with GSRS, group B; 12 patients without GSRS). The relationship between GSRS including clinical findings and IMMC was studied from 1.5 to 3 years after operation. A catheter equipped with a micro-tip force transducer was inserted transnassally into the remnant stomach and duodenum in a supine position, and the IMMC was studied. All patients were Stage â A(mucosal cancer, no lymph node metastasis, no distant metastasis). The remnant stomach was 1/3 compared with stomach size before operation. The length of the antral cuff in group A(1.5±0.2 cm)was significantly shorter than group B(3.2±0.3 cm)(p =0.0004). Appetite was significantly recognized in group B compared with group A(p=0.0067). PAF was significantly recognized in group A compared with group B(p=0.0001). Reflux esophagitis was found in group A more than group B. Early dumping syndroms did not found significant differences in both groups. In endoscopic esophagogastric finding of the remnant stomch, gastritis with GSRS was significantly found in group A compared with group B(p=0.0001). The IMMC was significantly recognized in group B compared with group A(p<0.0001). The occurrence of the PAF due to the GSRS may be caused by abscens of the IMMC.
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Muñón Gástrico , Gastroparesia , Neoplasias Gástricas , Femenino , Gastrectomía , Muñón Gástrico/cirugía , Humanos , Masculino , Persona de Mediana Edad , Complejo Mioeléctrico Migratorio , Píloro/cirugía , Neoplasias Gástricas/cirugíaRESUMEN
BACKGROUND: Toxoplasma gondii infection causes intestinal inflammation and diarrhea indicating possible intestinal motor dysfunction. Anatomical studies have shown alterations in the colonic myenteric plexus, but it is unknown whether this impacts motility and therefore whether motility is a target for treatment. We determined whether colonic coordinated movements are compromised by toxoplasmic infection and how it is associated with anatomical changes. METHODS: Male Wistar rats were evaluated at 6, 12, 24, 48, and 72 hours and 30 days postinfection (dpi) and controls. Infected rats received orally 5 × 103 sporulated oocysts of strain ME-49 (genotype II) of T gondii. The colon was collected for anatomical analysis (including the myenteric plexus immunolabeled with HuC/D, nNOS, and ChAT) and motility analysis in vitro (conventional manometry). Fecal output was measured daily. KEY RESULTS: At 12 hours postinfection, T gondii caused hypertrophy of the muscularis externa layer of the distal colon. There was loss of total, nitrergic, and cholinergic myenteric neurons in the proximal colon at 30 day postinfection (dpi); however, only loss of cholinergic neurons was found in the distal colon. Contractile complexes in the middle and distal colon were longer in duration in infected animals, which was associated with slower migration of the colonic motor complex. However, gastrointestinal transit time and fecal pellet output remained unchanged during the T gondii infection. CONCLUSIONS AND INFERENCES: Toxoplasma gondii caused myenteric neuronal loss in the proximal and distal colon and altered the motility pattern in the middle and distal colon to a more propulsive phenotype.