Gastroduodenal Motility Research Articles

Interdigestive relationship between gallbladder and gastroduodenal motility and bile salt secretion

Interdigestive relationship between gallbladder and gastroduodenal motility and bile salt secretion

Increased volume density of somatostatin- and decreased volume density of serotonin- and motilin-immunoreactive cells associated with changed gastroduodenal fasting motility in obese subjects

Increased volume density of somatostatin- and decreased volume density of serotonin- and motilin-immunoreactive cells associated with changed gastroduodenal fasting motility in obese subjects

Overinterpretation of gastroduodenal motility studies: Two cases involving Munchausen syndrome by proxy

Two children were thought to have an atypical gastroduodenal motility disorder because of the history and clinical course; both had received parenteral alimentation because of claims of inability to tolerate enteral feedings, and both continued to have unusual medical problems during parenteral alimentation. Both children had motility studies that were interpreted by a pediatric gastroenterologist to be "abnormal" and "diagnostic" of a motility disorder, but each was eventually shown to have a behavioral abnormality related to Munchausen syndrome by proxy. (J P EDIATR 1995;126:397-400)

Gastric output of IgA in man: relation to migrating motility complexes and sham feeding.

The immunologic reactivity of the gastric mucosa is poorly understood. The origin and dynamics of immunoglobulin A (IgA) occurring in the gastric lumen were investigated in healthy, Helicobacter pylori-negative volunteers. Gastroduodenal manometric motility recordings were combined with gastric luminal perfusion, enabling calculation of gastric acid output and analysis of the total IgA output. Acid output and total IgA correlated with the migrating motility complexes (MMC). The gastric IgA release showed maximal values in association with gastric motility phase III (maximal motor activity) and lowest values during phases I and II (none or irregular motor activity). The IgA output correlated with neither swallowed saliva (as indicated by amylase in the gastric perfusate) nor duodenogastric reflux (as indicated by gastric occurrence of bilirubin and/or duodenally infused PEG4000). Stimulation of gastric acid secretion by sham feeding during phase II-like motor activity (n = 6) induced a rapid and transient doubling of IgA output. There was no significant correlation between gastric acid secretion and gastric IgA release. Substantial amounts of IgA are released into the human stomach, most likely originating from the gastric mucosa. The up-regulation of IgA release in association with the activity front of the MMC and anticipatory to food intake suggests a neuroendocrine control of gastric mucosal immune responses.

Duodenal pH governs interdigestive motility in humans.

In this study, we examined the potential influence of duodenal pH in regulating the occurrence of the interdigestive migrating myoelectric complex (IMMC). Fasting gastroduodenal motility, duodenal pH, and plasma motilin were studied in 15 healthy subjects. During phase I, duodenal pH remained stable at 7 +/- 0.2. Phase II was accompanied by a lowering of duodenal pH, which fluctuated between 2.0 and 7.5. During late phase II, the duodenal pH increased to 6.9 +/- 0.3 and remained in the alkaline range during phase III. In six of 46 episodes of the IMMC, the occurrence of gastric phase III was delayed. This was associated with a persistently low duodenal pH (< 4) during late phase II. Despite a normal cyclic increase of plasma motilin, no gastric phase III activity was observed until the duodenal pH exceeded 7.0. Further studies showed that lowering of duodenal pH by intraduodenal perfusion of HCl prevented the occurrence of gastric phase III. We concluded that regularity of IMMC is governed by duodenal pH. An alkaline pH is essential for the initiation of gastric phase III; lowering of duodenal pH prevents its occurrence despite normal cyclic increase of plasma motilin.

Effects of resection of celiac and pyloric branches of vagus nerve on the interdigestive motor activity of the upper digestive tract and biliary tree.

It has been reported that interdigestive motor activities occur in the gallbladder and sphincter of Oddi as well as in the gastroduodenal tract and truncal vagus nerves modulate the gastroduodenal motility pattern. In the present study, the vagal branches which influence on the interdigestive motor activity of these organs were determined in conscious dogs. In the normal dog, interdigestive motor activities closely related to interdigestive migrating motor complex (IMC) in the gastric antrum and descending duodenum were recorded in the gallbladder and sphincter of Oddi. In dogs whose celiac branches of the vagus nerve were chronically resected, cycle periods of interdigestive motor activity in the stomach, duodenum, gallbladder and sphincter of Oddi significantly prolonged as compared with those in the normal dog but the interrelation of them persisted. Quiescent period in motility prolonged and the active period shortened. Resection of the pyloric branches had no influence on the interdigestive motor activities in all organs. The results imply that celiac branches of the vagus nerve modulate the interdigestive motor activity in the stomach, descending duodenum, gallbladder and sphincter of Oddi.

Gastroduodenal motility in mechanically ventilated critically ill patients

To determine the main characteristics of gastroduodenal motility in mechanically ventilated, critically ill patients. Case series; comparison with a parallel control group. Intensive care unit in a university teaching hospital. Twelve adult critically ill patients who required > 2 days of mechanical ventilation as a consequence of neurologic or respiratory disease. Control sample of 12 overnight, fasting, healthy volunteers. Pressure changes in the gastric antrum, proximal duodenum, and distal duodenum were simultaneously recorded during a 4-hr period by a multilumen tube (perfused catheter technique). The migrating motor complex and its three successive phases were identified according to usual definitions (phase 1, period of quiescence; phase 2, period of irregular contractile activity; phase 3 or activity front, period of high-frequency, regular contractions). Contractions and activity fronts at each site were quantified. The mean duration of the migrating motor complex was determined in the duodenum, as well as the contribution of each phase (phases 1, 2, 3) to the length of the complete cycle. The propagation characteristics of each activity front were assessed visually. In the patients, the number of contractions was markedly decreased in the antrum, where activity fronts were totally absent. In the duodenum (proximal and distal), the number of contractions and the occurrence of activity fronts were comparable in both groups. Although the duration of the duodenal migrating motor complex was similar in the two groups, the relative contribution of the quiescence period (phase 1) to the total cycle length increased and the contribution of phase 2 decreased in the patients. Three patients exhibited abnormally propagated (retrograde or stationary) activity fronts in the duodenum. Gastroduodenal motility is severely impaired in this group of mechanically ventilated patients. Activity fronts of the migrating motor complex never originated in the stomach, which was hypokinetic; qualitative disorders of the migrating motor complex were present in the duodenum. The loss of peristaltic activity in the stomach and, to a lesser degree, in the duodenum is consistent with an important role for motility disorders in the occurrence of digestive microbial overgrowth in such patients.

Role of CCK in the physiological control of gastroduodenal and intestinal motility in chickens.

Role of CCK in the physiological control of gastroduodenal and intestinal motility in chickens.

Experimental studies on the gastroduodenojejunal motility and gastric emptying after duodenectomy with preservation of the total stomach and pylorus

It is of interest to know whether or not the removal of the pyloric branch of the vagus nerve (subsequently referred to as vagotomy) is associated with the early stagnation of gastric contents supervening upon duodenectomy with preservation of the total stomach and pylorus (innervation of pylorus group 5, denervation of pylorus group 5). In the present study preservative duodenectomy was performed on dogs to determine the effects of vagotomy on gastroduodenojejunal motility and gastric emptying. The group of typical strong preprandial contraction waves (subsequently referred to as phase III) did not appear after vagotomy. The appearance of phase III was delayed and its duration was reduced. The duration of pyloric phase III significantly reduced, at 2 and 4 weeks post-surgery, in the denervation of pylorus group, compared to the innervation of pylorus group, and at 4 weeks, the area of phase III was significantly decreased in the denervation group. Post-vagotomy gastric emptying was poor throughout the course of observation. The results of this study suggest that the vagotomy-induced change in gastroduodenal motility in fasting conditions is one of the factors responsible for the stagnation of gastric contents.

Mechanism of action of CCK in avian gastroduodenal motility: evidence for nitric oxide involvement.

Our objective was to study the mechanism of action of cholecystokinin (CCK) on the motility of the gastroduodenal area. Chickens were implanted with five electrodes for electromyography in the stomach and duodenum. The effects of CCK (10(-9) mol.kg-1.10 min-1) were studied against the presence of several antagonists and in vagotomized animals. CCK caused inhibition of gastric motility and duodenal hyperactivity. Vagotomy blocked CCK responses in the stomach but not in the duodenum. Hexamethonium partially blocked gastric inhibition induced by CCK. NG-nitro-L-arginine methyl ester blocked the inhibitory response to CCK in the stomach but did not modify duodenum response. L-Arginine did not modify CCK actions. Opioid antagonists naloxone and naltrindole and adrenergic antagonists phentolamine and propranolol did not modify CCK response. Atropine did not modify duodenal response to CCK. Sodium nitroprusside (10(-8)-10(-6) mol/kg) inhibited gastroduodenal activity in a dose-related manner. We suggest that gastric response to CCK is vagally mediated, mainly by the nitric oxide system. Duodenal hyperactivity seems to be a direct action of CCK. Nitric oxide is a putative neurotransmitter in the chicken gut.

Organization of antral, pyloric and duodenal motility in patients with gastroparesis

AbstractThe motor mechanisms associated with delayed gastric emptying are poorly understood, and the contribution of abnormal patterns of gastroduodenal motility to gastroparesis is unknown. Limited data suggest an increased frequency of localized pyloric contractions contributes to delayed gastric emptying. Antropyloroduodenal pressures and gastric emptying of 99mTc chicken liver/ground beef were recorded simultaneously for 60 min in 16 patients with gastroparesis and 26 healthy subjects, using a sleeve/sidehole manometric assembly and a scintigraphic technique. Manometric recordings were analysed for localized pyloric contractions (isolated pyloric pressure waves), basal pyloric pressure (tone), antral and duodenal pressure waves and the number of associated antropyloroduodenal contractions ≥6 cm in length. There was no significant difference in median pyloric tone (1.1 (interquartile range 0.3–2.1) vs 0.5 (0–1.8)mmHg), number of isolated pyloric pressure waves (15 (4.5–25) vs 25 (12–37)) or antral pressure waves (47 (16–62) vs 46 (17–76) between the patients with gastroparesis and the healthy controls. The number of duodenal pressure waves was significantly less in the gastroparetics (54 (41–80) vs 102 (63–116), P &lt; 0.05) as was the number of antropyloroduodenal pressure waves ≥6 cm (5 (0.5–6) vs 12.5 (4–24), P &lt; 0.05). There was no difference in the lag time for solid gastric emptying, but there was a reduction in the amount emptied after 60 min (1 (0–10) vs 10 (0–14)%, P &lt; 0.01). These results suggest that abnormal patterns of antropyloroduodenal contractions contribute to slow gastric emptying in patients with gastroparesis. Localized pyloric contractions are not a major pathogenetic mechanism.

Prolonged monitoring of the upper gastrointestinal tract using echo planar magnetic resonance imaging.

Upper gastrointestinal motility and transit has been studied in five human volunteers with the ultra high speed, magnetic resonance imaging (MRI) technique MBEST (Modulus Blipped Echo-planar Single pulse Technique), a variant of echo planar imaging. Snapshot images requiring a data acquisition time of only 64-128 msec allowed visualisation of peristalsis in the antrum and duodenum in real time, without motional image degradation, as would normally be seen using conventional MRI. Gastroduodenal flow of the luminal contents was visualised using water as a contrast medium, with appropriate adjustment of the time constant (T2) weighting of the system. Rapid (0.3 Hz) imaging of gastroduodenal motility in both transverse and coronal planes was achieved by respiratory gating to the imaging frequency, allowing repetition rates of up to 20 frames per minute for 2-3 hours. Fast replay of stored images, to produce a 'movie loop', allowed identification of fasting motility patterns of the gastric antrum and proximal small intestine, with depiction of the phases of the migrating motor complex. Images of the fed patterns after the ingestion of a test meal showed good separation of solid and liquid particulate matter and mixing waves in the gastric body. The potential for quantitative measurements with this new imaging modality of the gastrointestinal tract is under development, which will allow us to measure transit and correlate this with motility data.

Gastric acid inhibits antral phase III activity in duodenal ulcer patients.

Fourteen patients with duodenal ulcers and eight healthy volunteers were examined to measure interdigestive gastroduodenal motility and plasma motilin. In order to study the effects of gastric acid on the gastroduodenal motility, 20 mg of famotidine was administered intravenously. The motility index of the gastric antrum and the duodenum, as well as the pH in the duodenal bulb were calculated. The duodenal pH was significantly lower and the gastric motility index was significantly weaker before the duodenal interdigestive migrating complex (IMC) in the ulcer patients than in the controls. Motilin levels increased before the duodenal IMC and decreased afterwards in both groups. Famotidine significantly increased the duodenal pH and the gastric motility index before the IMC, but no changes in the motilin level were noted. We conclude that duodenal ulcer patients have duodenal hyperacidity that results from increased inflow from the antrum and antral hypomotility during the gastric IMC and that these changes are normalized by the administration of famotidine. These results suggest that gastric acid inhibits antral contraction during the gastric IMC.

Gastric axial forces in experimentally delayed and accelerated gastric emptying.

The aim of this study was to assess the relationship between altered axial forces and gastric emptying of solids by experimentally inhibiting or stimulating gastric axial forces by intraduodenal lipid or intravenous erythromycin, respectively. In 15 healthy volunteers, we simultaneously measured gastric emptying of solids by scintigraphy, gastroduodenal motility by manometry, and forces along the longitudinal axis of the distal stomach by an axial force transducer. When 25% of the radiolabel had emptied from the stomach, subjects (n = 5 in each group) received normal saline (controls), intraduodenal lipid, or intravenous erythromycin. The test period consisted of the infusion period (10 min) and the subsequent 30 min. Lipid significantly reduced and erythromycin increased axial forces compared with control (lipid: median 0.6 N [0-1.4 interquartile range (IQR)]; erythromycin: median 18.2 N (16.5-20.5 IQR); control: median 4.7 N (3.9-5.2 IQR); P < 0.01). Similarly, antral phasic pressure activities were different relative to control. Gastric axial forces correlated significantly with gastric emptying (Spearman rank correlation = 0.86; P < 0.01). These data are consistent with the hypothesis that axial forces affect gastric emptying of solids and suggest that measurement of axial forces provides an assessment of overall gastric propulsion during the emptying of solids.

Gastroduodenal dysfunction and bacterial colonisation of the ventilated lung

The source of ventilator-associated pneumonia (gastric or oropharyngeal flora) remains controversial. We investigated the source of bacterial colonisation of the ventilated lung in 100 consecutive intensive-care patients. Gram-negative bacilli were isolated from the lower respiratory tract in 19 patients. Bacteria isolated from the stomach contents either previously or at the same time were identical to lower respiratory isolates in 11 patients. No gram-negative oropharyngeal isolate was identical to a lower respiratory tract isolate. Gastric bacterial overgrowth with gram-negative bacilli was associated with the presence of bilirubin in the stomach contents. Detectable bilirubin was also associated with subsequent acquisition of gram-negative bacilli in the lower respiratory tract. Only 5 gastric aspirate specimens with pH <3·5 contained gram-negative bacilli. These results establish a relation between duodenal reflux and subsequent bacterial colonisation of the lower respiratory tract. Restoration of normal gastroduodenal motility might help prevent pneumonia in intensive-care patients.

The Inhibitory Effect of Octreotide on Exocrine Pancreatic Secretion in Conscious Dogs

The effects of somatostatin and its analogue, octreotide (SMS201-995), on pancreatic secretion and gastroduodenal motility in response to secretin and cholecystokinin octapeptide (CCK-8) were studied in five conscious dogs. Intravenous infusions of octreotide or somatostatin (1 nmol kg-1 h-1) inhibited periodic pancreatic secretion and the potentiation of fluid and bicarbonate responses to secretin at 60 ng kg-1 h-1 associated with the interdigestive gastroduodenal motility peaks (migrating motor complex). Pancreatic fluid and bicarbonate responses to secretin (125-1,000 ng kg-1 h-1) were not inhibited by octreotide or somatostatin. Pancreatic protein and enzyme responses to secretin and CCK-8 at 50 and 100, but not at 200 and 400, ng kg-1 h-1 were inhibited by octreotide and somatostatin. These inhibitory effects were similar to those of atropine (25 micrograms kg-1 h-1). The inhibition of protein responses to CCK-8 (100 ng kg-1 h-1) was dependent on octreotide dose. It is concluded that both octreotide and somatostatin, like atropine, inhibit interdigestive pancreatic secretion and the responses to small, but not large, doses of secretin and CCK-8 in conscious dogs.

Cholinergic regulation of phase II interdigestive pancreatic secretion in humans.

Small fluctuations in cholinergic input may be involved in the regulation of human interdigestive pancreatic secretion. To determine the effects of small changes in cholinergic tone on phase II interdigestive trypsin secretion, we gave cholinergic agonists or antagonists to 17 healthy fasting subjects who underwent gastrointestinal intubation. Duodenal trypsin outputs, gastroduodenal motility, and plasma levels of pancreatic polypeptide (PP) as a marker of cholinergic tone were measured during intravenous infusion of bethanechol (0, 5, or 40 micrograms.kg-1.h-1) or atropine (0, 4, or 16 micrograms.kg-1.h-1) given during phase II alone or in combination based on a 3 x 3 factorial design. Data were evaluated by a response surface analysis of the average log values for the test period (using the average of log values of the control period as a covariate). Bethanechol increased trypsin output (p < 0.05) and plasma concentrations of PP (p < 0.05) within the ranges of spontaneous fluctuations of trypsin output and PP during phase II, but did not disrupt the periodicity of pancreatic secretion or the characteristic cyclical pattern of interdigestive motility and induction of phase III activity. Atropine markedly decreased trypsin output (p < 0.05) and plasma concentrations of PP (p < 0.05) and abolished the cycling of interdigestive pancreatic secretion and motor activity. These data suggest the hypothesis that cholinergic pathways participate in the control of interdigestive pancreatic secretion during phase II, while enzyme secretion during phase III may be regulated by other mechanisms.

Effects of cholecystokinin and gastrin on gastroduodenal motility and coordination in chickens

Cholecystokinin (CCK) has not been isolated from chicken gut yet and there has been no study on the effects of chicken gastrin (CG), the only gastrin/CCK peptide isolated from avian gut, on gastrointestinal motility. The main objective was to study the effects of CCK and CG on gastroduodenal motility and coordination in chickens. Electrodes for electromyography were implanted in the stomach and proximal and distal duodenum of 4 wk old chickens. Sulphated CCK-octapeptide (CCK8) (10 −10 to 10 −8 moles/kg), CCK-tetrapeptide (CCK4) (2×10 −10 to 2×10 −8 moles/kg) and CG (3×10 −10 to 10 −8 mole/kg) were given in a 10 min i.v infusion. All these peptides induced a dose-dependent inhibition of gastric motility. CCK8 induced a duodenal hyperactivity whereas CCK4 and CG induced a duodenal inhibition. Neither the CCK-A receptor antagonist L364,718 nor the CCK-B receptor antagonist L365,260 (10 −9 − 10 −7 moles/kg) antogonized CCK8 actions. From these results we suggest that the receptors mediating CCK effects are different from those of mammals. The site of action for these peptides is the same in the stomach whereas in the duodenum there are two different ones, one mediating excitation and the other inhibition. These results suggest a physiological role for CCK regulating gastroduodenal motility in birds.

Open Study of the Clinical Effects of Lansoprazole in the Treatment of Reflux Oesophagitis

The clinical efficacy and safety of lansoprazole, administered in a dose of 30mg once daily after breakfast, were studied in an open trial with 38 patients with erosive/ulcerative reflux oesophagitis. In 3 of these patients, the effect on gastro-oesophageal reflux and gastroduodenal motility was also investigated by 24-hour pH and motility monitoring, performed before and 1 week after starting lansoprazole therapy.

Somatostatin 28 and coupling of human interdigestive intestinal motility and pancreatic secretion

To determine the effects of small increases in somatostatin 28 plasma concentrations on human interdigestive gastrointestinal motility and pancreatic secretion, six fasting volunteers were intubated with gastroduodenal multilumen tubes and motility and pancreatic enzyme secretion were measured. Subjects received intravenous NaCl and somatostatin 28 at 11 and 44 pmol · kg−1 · h−1 for 120 minutes or at least one interdigestive cycle. The two doses increased plasma somatostatin 28 levels within the physiological or into the supraphysiological range, respectively. Somatostatin 28 at 11 and 44 pmol · kg−1 · h−1 decreased the length of the interdigestive motility cycle by 50% and 67% compared with controls, respectively (both P < 0.002). Propagation velocity of the migrating motor complex (P < 0.01) and plasma motilin were decreased (P < 0.01). The smaller and larger dose decreased pancreatic enzyme outputs by 50% and 65%, respectively (P < 0.005), but with the smaller dose, phase III-associated enzyme outputs were greater than phase I outputs. These findings suggest that small changes in somatostatin 28 plasma concentrations modulate human interdigestive motility and pancreatic enzyme output while coupling of motor and secretory events is preserved.