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Benson T. Massey - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of Upper Esophageal Sphincter Function
    Perspectives on Swallowing and Swallowing Disorders (Dysphagia), 2012
    Co-Authors: Tarun Sharma, Benson T. Massey
    Abstract:

    Under normal circumstances, the upper Esophageal Sphincter (UES) serves as an important gatekeeper, regulating antegrade and retrograde bolus movement through the upper aerodigestive tract. Dysfunc...

  • Transient lower Esophageal Sphincter relaxations do not result from passive opening of the cardia by gastric distention
    Gastroenterology, 2006
    Co-Authors: Benson T. Massey, Chelsey Simuncak, Nicole J. Lecapitaine-dana, Sudhindra Pudur
    Abstract:

    Background & Aims: Transient lower Esophageal Sphincter relaxation is the main mechanism for gastroEsophageal reflux. Although there is evidence that transient lower Esophageal Sphincter relaxations are neurally mediated, another school of thought is that transient lower Esophageal Sphincter relaxations result from gastric distention, which shortens the Sphincter to the point where it opens and the pressure decreases. We assessed the relationship of transient lower Esophageal Sphincter relaxation to gastroEsophageal junction opening in an unsedated human model. Methods: Seven healthy volunteers (6 men and 1 woman, aged 18–53 years) were studied while they were sitting. Manometry was performed by using a sleeve catheter passed through 1 nostril. A 5.3-mm endoscope was placed through the other nostril to obtain a retroflexed view of the cardia. The biopsy channel was connected to a barostat to distend the stomach with air at 15 mm Hg for 30 minutes. Manometric and endoscopic video-recording times were synchronized but scored independently. Results: The transient lower Esophageal Sphincter relaxation onset invariably preceded gastroEsophageal junction opening (median, 5.0 seconds; range, 0.5–20.7 seconds; P P Conclusions: These data refute the hypothesis that transient lower Esophageal Sphincter relaxations result from passive mechanical distraction of the gastroEsophageal junction. Rather, transient lower Esophageal Sphincter relaxations must occur before the gastroEsophageal junction can open.

  • Alteration of the upper Esophageal Sphincter belch reflex in patients with achalasia
    Gastroenterology, 1992
    Co-Authors: Benson T. Massey, Wylie J. Dodds, Walter J. Hogan, Roberto Oliveira Dantas
    Abstract:

    Abstract Some patients with achalasia have been reported to develop airway obstruction from a massively airdistended esophagus, which may represent an abnormality in the upper Esophageal Sphincter belch reflex. When questioned carefully, 95% of our achalasia patients reported difficulty with belching. The upper Esophageal belch reflex in 23 consecutive achalasia patients and 12 healthy controls was studied using an upper Esophageal Sphincter sleeve manometry catheter and rapid injection of 20–50 mL of air into the midesophagus. Compared with normal subjects, achalasia patients were significantly less likely to have an Esophageal belch for all volumes tested and were more likely to have an increase rather than a decrease in upper Esophageal Sphincter pressure in response to air injection. This study systematically documents that many achalasia patients have an alteration in the upper Esophageal Sphincter belch reflex that may be a contributory mechanism for some of the chest and upper airway symptoms reported by some patients during acute Esophageal distension.

Anders Lehmann - One of the best experts on this subject based on the ideXlab platform.

  • transient lower Esophageal Sphincter relaxations in dogs are inhibited by a metabotropic glutamate receptor 5 antagonist
    European Journal of Pharmacology, 2005
    Co-Authors: Jorgen Jensen, Anders Lehmann, Anna Uvebrant, Anita Carlsson, Gunilla Jerndal, Karolina Nilsson, Claudine L Frisby, Ashley L Blackshaw, Jan P Mattsson
    Abstract:

    Abstract Transient lower Esophageal Sphincter relaxation is the major mechanism for gastroEsophageal reflux. The present study was initiated to investigate the potential effect of the metabotropic glutamate 5 (mGlu5) receptor antagonist, 2-methyl-6-(phenylethynyl)-pyridine (MPEP), on transient lower Esophageal Sphincter relaxations in the conscious dog. MPEP (1.4–8.7 μmol/kg i.v.) produced a dose-dependent inhibition of transient lower Esophageal Sphincter relaxations (59 ± 11% inhibition at 8.7 μmol/kg). In addition, there was a reduction of the number of reflux episodes and an increase in latency time to the occurrence of the first transient lower Esophageal Sphincter relaxation. No effect was seen on basal lower Esophageal Sphincter pressure or on swallowing. It is concluded that the mGlu5 receptor antagonist MPEP potently inhibits transient lower Esophageal Sphincter relaxations and that the mGlu5 receptor is a potential target for treatment of gastroEsophageal reflux disease.

  • Effects of antagonism of NMDA receptors on transient lower Esophageal Sphincter relaxations in the dog
    European journal of pharmacology, 2001
    Co-Authors: Anders Lehmann, Lena Brändén
    Abstract:

    Transient lower Esophageal Sphincter relaxation is the major cause of gastroEsophageal reflux. Mechanisms underlying transient lower Esophageal Sphincter relaxation are poorly understood although gastric mechanosensitive vagal afferent pathways play a central role. Glutamate is a key transmitter of vagal afferents acting partly on NMDA receptors. The aim of this work was to study the effects on transient lower Esophageal Sphincter relaxation in awake dogs (n=5) of the competitive NMDA receptor antagonist cis-4-phosphonomethyl-2-piperidine carboxylic acid (CGS 19755; 0.3 and 3 mg/kg i.v., the high dose was given at two separate occasions to each dog). Transient lower Esophageal Sphincter relaxations were evoked by intragastric infusion of a liquid meal followed by air insufflation and were scored during a 45-min period. Neither dose produced any significant effect on the group average number of transient lower Esophageal Sphincter relaxations. Synchronous contractions of the esophagus were commonly seen during transient lower Esophageal Sphincter relaxation and CGS 19755 at both doses greatly reduced their occurrence. The findings indicate that NMDA receptor antagonism selectively inhibits the Esophageal component of transient lower Esophageal Sphincter relaxation although the rate of transient lower Esophageal Sphincter relaxations is not consistently affected.

Lena Brändén - One of the best experts on this subject based on the ideXlab platform.

  • Effects of antagonism of NMDA receptors on transient lower Esophageal Sphincter relaxations in the dog
    European journal of pharmacology, 2001
    Co-Authors: Anders Lehmann, Lena Brändén
    Abstract:

    Transient lower Esophageal Sphincter relaxation is the major cause of gastroEsophageal reflux. Mechanisms underlying transient lower Esophageal Sphincter relaxation are poorly understood although gastric mechanosensitive vagal afferent pathways play a central role. Glutamate is a key transmitter of vagal afferents acting partly on NMDA receptors. The aim of this work was to study the effects on transient lower Esophageal Sphincter relaxation in awake dogs (n=5) of the competitive NMDA receptor antagonist cis-4-phosphonomethyl-2-piperidine carboxylic acid (CGS 19755; 0.3 and 3 mg/kg i.v., the high dose was given at two separate occasions to each dog). Transient lower Esophageal Sphincter relaxations were evoked by intragastric infusion of a liquid meal followed by air insufflation and were scored during a 45-min period. Neither dose produced any significant effect on the group average number of transient lower Esophageal Sphincter relaxations. Synchronous contractions of the esophagus were commonly seen during transient lower Esophageal Sphincter relaxation and CGS 19755 at both doses greatly reduced their occurrence. The findings indicate that NMDA receptor antagonism selectively inhibits the Esophageal component of transient lower Esophageal Sphincter relaxation although the rate of transient lower Esophageal Sphincter relaxations is not consistently affected.

J Dent - One of the best experts on this subject based on the ideXlab platform.

  • Patterns of lower Esophageal Sphincter function associated with gastroEsophageal reflux.
    The American journal of medicine, 1997
    Co-Authors: J Dent
    Abstract:

    Studies in which lower Esophageal Sphincter and Esophageal pH have been monitored simultaneously have challenged the traditional concept that most reflux episodes result from weak steady state lower Esophageal Sphincter tone. Instead, the majority of reflux episodes have occurred during 5-35-second abrupt periods of complete Sphincter relaxation usually against a background of normal Sphincter tone. This distinctive pattern of relaxation, which has been named "transient lower Esophageal Sphincter relaxation," occurs independently of swallowing. It depends on vagal pathways and the hindbrain for its patterning and control, but many of these aspects are still not well understood. Control of transient lower Esophageal Sphincter relaxation by drug therapy is an attractive future option for management of supraEsophageal complications of reflux disease.

Ravinder K. Mittal - One of the best experts on this subject based on the ideXlab platform.