Duodenal pH dips as an index of transpyloric flow in conscious dogs

Malbert, C. H.; Ruckebusch, Y.

doi:10.1016/0016-5085(93)90893-h

Cited by 5 publications

(12 citation statements)

References 16 publications

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“…However, we observed that the duodenal pH may recover while the impedance remains low, suggesting that the bolus remains present but with a higher pH, which may result on mixing with a buffer. It has been reported that the exclusion of bile lowered duodenal pH by reducing the buffering capacity of the duodenal juice, but in this model pH drops associated with transpyloric passage of fluid persisted, indicating that other sources of alkaline buffer are sufficient to maintain an almost-neutral pH (32). There are two sources of bicarbonate in the duodenum: from the pancreas, but also directly secreted by duodenal epithelial cell (1,18,26).…”

Section: Discussionmentioning

confidence: 97%

“…As a consequence, data on transpyloric and proximal duodenal transport and pH variations were limited to animal studies. However, important data have been obtained by implantation of electromagnetic flowmeters in dogs by Malbert et al who have described patterns of duodenal pH drops in relation to transpyloric chyme transport, both in the interdigestive and in the postprandial period (32,33). Recently several reports have suggested that impedance monitoring is an important tool to assess fluid transport in the antroduodenal area (41), distal duodenum (36), and small bowel (22).…”

Section: Discussionmentioning

confidence: 97%

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Duodenal Acid Clearance in Humans: Observations Made with Intraluminal Impedance Recording

2005

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Duodenal acid clearance appears to be involved not only in the pathogenesis of duodenal ulcer disease but also in functional dyspepsia. Duodenal contractile activity can help to maintain neutral pH in the duodenum by mixing acid with bicarbonate or by aborally transporting the acid load. Intraluminal impedance recording, allowing the detection of nonacid liquid boluses, can be carried out concomitantly with antroduodenal manometry and pH recording and may thus provide useful information about the mechanisms involved in duodenal clearance of endogenous acid and volume boluses. Eight H. pylori-negative healthy volunteers were studied with two catheters positioned across the pylorus, allowing the recording of five impedance signals (one antral, one pyloric, and three duodenal) simultaneously with six pressure signals (two antral, one pyloric, and three duodenal) as well as distal antral and proximal duodenal pH. During phase II of the migrating motor complex, which is known to be associated with the highest duodenal acid exposure, each duodenal acidification event (defined as a pH drop >2 pH units) was characterized by its maximal amplitude, duration, temporal relationship with antroduodenal manometric events, and relation to impedance variations. Acid was considered to have been cleared from the duodenum when the preacidification pH was restored (+/-0.2 unit). A total of 164 duodenal pH drops were recorded during the 323 min of phase II recordings. Eleven percent of the duodenal acidification events were short-lived (<10 sec). All of these events were temporally associated with a propagated antroduodenal contraction and a short-lived drop in impedance, suggesting rapid aboral passage of the acid bolus. The long-lived duodenal acidification events lasted a mean of 32 sec (range, 25-66 sec). In 90% of these events an antroduodenal propagated contraction was recorded at the time of onset. Repetitive duodenal contractions followed the onset of the long-lived acidification events in 34% of the cases. These remained present until complete clearance of the acid. In 81% of the long-lived acidification events, recovery of the associated impedance drop occurred simultaneously with the pH recovery, suggesting a complete clearance of the bolus. Less frequently (19%), the duodenal pH recovered while the impedance remained low, suggesting that the bolus was not cleared but neutralized. Interdigestive duodenal acidification events usually last about 30 sec. They evoke duodenal contractions in only one-third of cases. Combined pH and impedance recording makes it possible to distinguish between neutralization of acid boluses and their complete total clearance.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 97%

Duodenal Acid Clearance in Humans: Observations Made with Intraluminal Impedance Recording

2005

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“…The pylorus constitutes a restrictive resistance to flow from the stomach into the duodenum and vice versa. The pyloric diameter, as controlled by the tonic contraction of the DPL, sets the baseline resistance to flow 6,7,18,20–22 . Resistance increases intermittently and sharply as the pylorus participates in the phasic contraction of gastric peristalsis and closes the entire pyloric segment.…”

Section: Pyloric Flow and Gastric Emptyingmentioning

confidence: 99%

“…The intermittent contraction of the PPL and the resulting closure of the pylorus contribute to the pulsatile nature of much gastric emptying. Malbert and Ruckebusch 20 contrasted pyloric flow pulses in the fasted and the fed state. During fasting, outflow of gastric chyme was preceded by a fundic contraction, followed by a contraction of the antrum and the pylorus.…”

Section: Pyloric Flow and Gastric Emptyingmentioning

confidence: 99%

“…Classic observations of pyloric activity relied on dynamic contrast radiography, typically in conjunction with strain gauges, pressure transducers or inductography to track the pyloric diameter 6,7,20 . This demonstrated that the pylorus is patent much of the time, and that its tonic activity controls the luminal diameter and flow resistance.…”

Section: Activity Of the Pylorus And Recording Techniquesmentioning

confidence: 99%

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The pylorus

Ramkumar

Schulze

2005

Neurogastroenterology Motil

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The pylorus controls the flow between a reservoir dedicated to mechanical and chemical digestion (the stomach) and a conduit dedicated to the absorption of nutrients (the intestines). The pylorus adjusts gastric outflow resistance to physiological needs. It allows the outflow of isotonic fluids yet selectively retains particles too large for delivery to the intestines and in concert with the antrum further processes them (gastric sieving). Unlike most gut sphincters, the pylorus, at least of man, maintains a patent lumen most of the time. It only intermittently becomes a tightly closed barrier that arrests all flow out of and into the stomach. The geometry of the pylorus changes dramatically from the relaxed open state to closure. Pyloric closure involves contraction of its proximal and distal muscle loops, and occlusion of its lumen by mucosal folds. Current studies that combine pressure recordings with imaging by magnetic resonance imaging or ultrasound and fluid-mechanical analysis shed new light on the role of the pylorus in gastric emptying and digestion. Much has been learned in recent years on the innervation of the normal pylorus particularly from studies on infantile hypertrophic stenosis, and attempts are being made to treat gastroparesis by interventions on the pylorus.

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Endoscopic and surgical treatment of non‐neoplastic proximal duodenal ulceration in dogs, and anatomical study of proximal duodenal vascularisation

Sabetti,

Cola,

Foglia

et al. 2023

J of Small Animal Practice

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ObjectivesProximal duodenal ulceration is often characterised by continuous bleeding, and treatment is challenging. The aims of this study were to investigate the role of vascularisation in proximal duodenal ulceration and describe clinical aspects, endoscopic features and treatment in dogs.Material and MethodsPolyurethane foam casts of gastroduodenal vessels were obtained from five dogs which had died from disorders unrelated to the digestive system. In addition, 12 dogs having proximal duodenal ulcers diagnosed by endoscopic examination were enrolled in a treatment trial. After the endoscopic diagnosis of a duodenal ulcer, all the dogs were treated medically and, in the absence of resolution, were subsequently treated by endoscopic electrocauterisation or by surgery.ResultsA submucosal vascular network was evident in all the casts, with a prominent venous plexus seen exclusively in the first half inch of the duodenum. In clinical cases, on endoscopic examination, the duodenal ulcer was located at the proximal part of the duodenum, involving the mesenteric portion of the wall. The dogs not responding to medical treatment (6/12) were treated with endoscopic electrocauterisation, surgical coagulation or resection of the proximal duodenal portion. All the dogs survived until discharge, and the median survival time following discharge was 107.5 days.Clinical SignificanceBased on the anatomical details highlighted in this study, the continuous bleeding observed in our patients may have been due to the prominent venous plexus evidenced at the level of the proximal duodenum. Surgical and endoscopic treatments in six patients resolved the ulcer bleeding with no recurrences noted during follow‐up.

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Duodenal pH dips as an index of transpyloric flow in conscious dogs

Cited by 5 publications

References 16 publications

Duodenal Acid Clearance in Humans: Observations Made with Intraluminal Impedance Recording

Duodenal Acid Clearance in Humans: Observations Made with Intraluminal Impedance Recording

The pylorus

Endoscopic and surgical treatment of non‐neoplastic proximal duodenal ulceration in dogs, and anatomical study of proximal duodenal vascularisation

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