Intrinsic corporoantropyloric coordination of motility and gastric emptying

1994 ◽  
Vol 266 (2) ◽  
pp. G255-G262 ◽  
Author(s):  
G. E. Holle ◽  
E. Steinbach ◽  
W. Forth

This study examined changes in gastric motility after interruption of the intramural nervous circuitry from the proximal portion of the stomach to the antrum by a circumferential gastric myotomy. Seven extraluminal strain gauge force transducers and five platinum electrodes were implanted along the antropyloroduodenal region, and gastric emptying was studied by X-ray after a 280-g solid meat meal mixed with barium. The motility index increased aboral to the myotomy by 106 and 69% in the distal antrum and pylorus, respectively, in the first postprandial 30-60 min because of the loss of an inhibitory neural influence from the proximal part of the stomach. Destabilization of the basic electrical rhythm occurred in 50% of the dogs. This was apparent as tachyarrhythmia or bradyarrhythmia and an early postprandial 2-11% decrease in slow-wave frequency and a 100% increase in slow-wave amplitude. Coordination of corporoantropyloric contractions was disorganized. Frequent segmenting and antidromic contractions were associated with reduced periods of optimal emptying and disturbed intragastric chyme transport into the constricted antrum. A 10-30% gastric emptying delay of approximately 50 min was a consequence of myotomy despite an increased antroduodenal motor gradient after myotomy. The overall results suggest that intact intramural innervation and muscular continuity are essential for coordination of corporoantropyloric motility and normal gastric emptying.

Gut ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 346-354 ◽  
Author(s):  
H P Parkman ◽  
D M Trate ◽  
L C Knight ◽  
K L Brown ◽  
A H Maurer ◽  
...  

BACKGROUNDCholinergic regulation of chronotropic (frequency) and inotropic (force) aspects of antral contractility and how these impact on gastric emptying are not well delineated.AIMSTo determine the effects of cholinergic stimulation and inhibition on myoelectric, contractile, and emptying parameters of gastric motility.METHODSTen normal subjects underwent three studies each, using simultaneous electrogastrography (EGG), antroduodenal manometry, and gastric emptying with dynamic antral scintigraphy (DAS). After 30 minutes of baseline fasting manometry and EGG, subjects received saline intravenously, atropine (0.6 mg then 0.25 mg/hour intravenously), or bethanechol (5 mg subcutaneously). This was followed by another 30 minutes’ recording and by three hours of postprandial recording after ingestion of a technetium-99m labelled solid meal.RESULTSDuring fasting, atropine decreased, whereas bethanechol increased, the antral manometric motility index and EGG power. Postprandially, atropine decreased the amplitude of antral contractions by DAS, decreased the postprandial antral manometric motility index, and slowed gastric emptying. Atropine caused a slight increase in postprandial frequency of antral contractions by DAS and gastric myoelectrical activity by EGG. Bethanechol slightly increased the amplitude, but slightly decreased the frequency of antral contractions by DAS and decreased the frequency of gastric myoelectrical activity by EGG, with no significant increase in the motility index or gastric emptying.CONCLUSIONSCholinergic antagonism with atropine reduces antral contractility and slows gastric emptying. Cholinergic stimulation with bethanechol increases antral contractility, but decreases the frequency of antral contractions, without altering the antral motility index or gastric emptying.


Gut ◽  
1998 ◽  
Vol 42 (2) ◽  
pp. 243-250 ◽  
Author(s):  
H P Parkman ◽  
J-L C Urbain ◽  
L C Knight ◽  
K L Brown ◽  
D M Trate ◽  
...  

Background—The effect of histamine H2receptor antagonists on gastric emptying is controversial.Aims—To determine the effects of ranitidine, famotidine, and omeprazole on gastric motility and emptying.Patients and methods—Fifteen normal subjects underwent simultaneous antroduodenal manometry, electrogastrography (EGG), and gastric emptying with dynamic antral scintigraphy (DAS). After 30 minutes of fasting manometry and EGG recording, subjects received either intravenous saline, ranitidine, or famotidine, followed by another 30 minutes recording and then three hours of postprandial recording after ingestion of a radiolabelled meal. Images were obtained every 10–15 minutes for three hours to measure gastric emptying and assess antral contractility. Similar testing was performed after omeprazole 20 mg daily for one week.Results—Fasting antral phase III migrating motor complexes (MMCs) were more common after ranitidine (9/15 subjects, 60%), famotidine (12/15, 80%), and omeprazole (8/12, 67%) compared with placebo (4/14, 29%; p<0.05). Postprandially, ranitidine, famotidine, and omeprazole slowed gastric emptying, increased the amplitude of DAS contractions, increased the EGG power, and increased the antral manometric motility index.Conclusions—Suppression of gastric acid secretion with therapeutic doses of gastric acid suppressants is associated with delayed gastric emptying but increased antral motility.


1993 ◽  
Vol 265 (4) ◽  
pp. G767-G774 ◽  
Author(s):  
J. C. Eagon ◽  
K. A. Kelly

Gastric pacing has been achieved in dogs and humans, but its effects on gastric motility and emptying have not been thoroughly explored. Seven dogs had bipolar electrodes placed 1 and 10 cm proximal to the pylorus for reverse and forward pacing and monopolar recording electrodes and strain gauges placed 3, 5, and 7 cm proximal to the pylorus. After recovery, myoelectrical and contractile activity and gastric emptying of a mixed meal (50 g 99mTc-labeled liver and 250 ml 111In-labeled 5% dextrose broth solution) were measured in each of three conditions: no pacing, reverse pacing, and forward pacing (frequency 0.5 cycles/min above intrinsic pacesetter potential frequency). Reverse pacing reversed the direction of > 90% of antral pacesetter potentials and peristaltic waves in six of seven dogs, prolonged the lag phase of solid emptying, prolonged the half emptying time of solids and liquids, and increased the antral motility index. Forward pacing entrained pacesetter potentials but had no consistent effect on emptying or antral contractions. In conclusion, reverse gastric pacing slows gastric emptying of digestible solids and liquids by reversing the direction of antral peristalsis and increasing the antral motility index, whereas forward pacing has no such effects.


1975 ◽  
Vol 58 (2) ◽  
pp. 471-474 ◽  
Author(s):  
Kenneth Lazara ◽  
Jose M. Zayas ◽  
Alfred Zajac
Keyword(s):  

2012 ◽  
Vol 303 (7) ◽  
pp. E853-E864 ◽  
Author(s):  
Xinfu Guan ◽  
Xuemei Shi ◽  
Xiaojie Li ◽  
Benny Chang ◽  
Yi Wang ◽  
...  

Glucagon-like peptides (GLP-1/2) are cosecreted from endocrine L cells in the gut and preproglucagonergic neurons in the brain. Peripheral GLP-2 action is essential for maintaining intestinal homeostasis, improving absorption efficiency and blood flow, promoting immune defense, and producing efficacy in treatment of gastrointestinal diseases. However, it is unknown if CNS GLP-2 plays a physiological role in the control of energy homeostasis. Since GLP-1/2 are cotranslated from preproglucagongene and coproduced by prohormone convertase-1, it is challenging to knockout GLP-2 only. Instead, our laboratory has generated a Glp2r-floxed mouse line to dissect cell-specific GLP-2 receptor GLP-2R) action in the regulation of energy balance. Our objective was to determine if GLP-2R in the hypothalamus modulates feeding behavior and gastric emptying. We show that Glp2r mRNA and protein are highly expressed in the arcuate nucleus and dorsomedial nucleus of the mouse hypothalamus. Using the Cre-LoxP system, we generated mice that lack Glp2r expression in POMC neurons (KO; mainly in the hypothalamus). The KO mice showed hyperphagic behavior (such as increases in food intake and meal frequency), accelerated gastric emptying (assessed by [13C]octanoic acid breath test), and late-onset obesity, yet there was no decrease in basal metabolic rate. Infusion of GLP-2 (2.5 nmol into the 4th ventricle) suppressed food intake and gastric emptying, while GLP-2-mediated effects were abolished in the melanocortin receptor-4 (MC4R) KO mice. We conclude that Glp2r deletion in POMC neurons enhances feeding behavior and gastric motility, whereas icv GLP-2R activation suppresses food intake and gastric emptying through the MC4R signaling pathway. This study indicates that CNS GLP-2R plays a physiological role in the control of feeding behavior and gastric emptying and that this is mediated probably through the melanocortin system.


2017 ◽  
Vol 38 (9-10) ◽  
pp. 181
Author(s):  
Badriul Hegar ◽  
Yvan Vandenplas

Disorders of gastric motility are generally manifested by an abnormal rate of gastric emptying. The emptying process of the stomach is very complex, and knowledge is limited to the observation that gastric emptying rate is a highly variable phenomenon, and that delayed gastric emptying is frequently the case. The advances in the knowledge of the physiology of gastric muscle and enteric nerves, and the recognition of the patterns of organization of smooth muscle contractions gave a new input to the study of gastric motility. The gastric emptying can be monitored in various ways, such as manometry, scintigraphy, or electrogastrography (EGG). Recently, EGG has received more attention. There is correlation between the EGG signal obtained from body surface electrodes and signals obtained directly from electrodes locates in the gastric muscle (serosal records). Some studies showed an association between EGG-findings and gastric motility disorders, and indicate that EGG is a reliable, non-invasive, useful method to detect gastric myoelectric activity.


2010 ◽  
Vol 298 (4) ◽  
pp. R1125-R1135 ◽  
Author(s):  
Yoshitaka Toyomasu ◽  
Erito Mochiki ◽  
Mitsuhiro Yanai ◽  
Kyoichi Ogata ◽  
Yuichi Tabe ◽  
...  

Monosodium l-glutamate (MSG) is a substance known to produce the umami taste. Recent studies indicate that MSG also stimulates a variety of activities in the gastrointestinal tract through its receptor in the gut, but no study has reported the activity in conscious large experimental animals. The aim of our study was to investigate whether direct intragastric MSG stimulates gut motility and to identify the mechanism in conscious dogs. Contractile response to intraluminal injection of MSG was studied in the fed and fasted states by means of chronically implanted force transducers. MSG (5, 15, 45, and 90 mM/kg) dissolved in water was injected into the stomach and duodenum in normal and vagotomized dogs. MSG solution was administered into the stomach before feeding, and gastric emptying was evaluated. Several inhibitors of gastrointestinal motility (atropine, hexamethonium, and granisetron) were injected intravenously before MSG administration to the stomach. The effect of MSG was investigated in Pavlov (vagally innervated corpus pouch), Heidenhain (vagally denervated corpus pouch), and antral pouch (vagally innervated) dogs. Upper gut motility was significantly increased by intragastric MSG but not significantly stimulated by intraduodenal MSG. Intragastric MSG (45 mM/kg) stimulated postprandial motility and accelerated gastric emptying. MSG-induced contractions were inhibited by truncal vagotomy, atropine, hexamethonium, and granisetron. Gut motility was increased by intrapouch injection of MSG in the Pavlov pouch, but it was not affected in the Heidenhain or antral pouch dogs. We conclude that intragastric MSG stimulates upper gut motility and accelerates gastric emptying. The sensory structure of MSG is present in the gastric corpus, and the signal is mediated by the vagus nerve.


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