Phasic contractions of the muscular components of human esophagus and gastroesophageal junction in vitro

1995 ◽  
Vol 73 (3) ◽  
pp. 356-363 ◽  
Author(s):  
Harold G. Preiksaitis ◽  
Nicholas E. Diamant
Keyword(s):  
Electrical Activity ◽  
Lower Esophageal Sphincter ◽  
Longitudinal Muscle ◽  
Gastroesophageal Junction ◽  
Gastric Fundus ◽  
Slow Waves ◽  
Phasic Activity ◽  
Esophageal Sphincter ◽  
Human Esophagus

This study was performed to assess the repetitive phasic mechanical and (or) electrical activity of the muscle from different regions of the human gastroesophageal junction (GEJ). Muscle strips from the circular and longitudinal layers of the gastric fundus and esophagus and of the clasp and sling components of the GEJ were obtained from surgical specimens and prepared for in vitro recording of contractile or electrical activity. Phasic contractions occurred in all regions except the longitudinal muscle of the gastric fundus and that overlying the sling. Robust phasic activity (2.6 ± 0.6 min−1) was most frequent (92% of specimens) in longitudinal muscle overlying the clasp, arising spontaneously in 67%. Stretch or carbachol stimulation increased the frequency of these contractions. Transmural electrical stimulation produced a transient cessation of phasic activity. Electrical recording showed slow waves with superimposed spiking coinciding with phasic contractions. These activities were unaltered by 1 μM atropine or 1 μM tetrodotoxin, but inhibited by 2 μM verapamil. In conclusion, several muscles of the human esophagus and GEJ manifest repetitive contractions in vitro, particularly the longitudinal muscle overlying the clasp muscle fibers. These oscillations are due to electrical slow waves, can potentially be modulated by intrinsic nerves, and may play a role in the intermittent phasic contractions of lower esophageal sphincter pressure in vivo.Key words: oscillators, myolgenic, cardia, pacemaker, lower esophageal sphincter.

The effect of eating on lower esophageal sphincter electrical activity

2009 ◽  
Vol 296 (4) ◽  
pp. G793-G797
Author(s):  
Claudia P. Sanmiguel ◽  
Yuichiro Ito ◽  
Masanobu Hagiike ◽  
Jeffrey L. Conklin ◽  
David Lalezari ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Lower Esophageal Sphincter ◽  
Esophageal Manometry ◽  
Longitudinal Axis ◽  
Implantable Device ◽  
Solid Food ◽  
Standard Meal ◽  
Esophageal Sphincter

Electrical activity of the lower esophageal sphincter (LES) has been recorded mainly in vitro and in anesthetized animals. Swallowing produces relaxation of the LES, followed by its contraction. These changes should be associated with changes in LES electrical activity. To determine whether changes in LES electrical activity can be used to recognize the beginning of a meal, four dogs were implanted with two electrodes in the longitudinal axis of the LES. The electrodes were connected to an implantable device for recording of electrical activity. After recovery, dogs underwent two experiments: 1) combined recordings of LES electrical activity and esophageal manometry to test the effect of dry swallows, water, and solid food swallows on LES electrical activity and 2) telemetric recording of LES electrical activity during a standard meal. All amplitudes were in mV, means ± SD, ANOVA, P < 0.05. In experiment 1, an increase in the amplitude of LES electrical activity was associated with the substance being swallowed, i.e., at rest: 0.31 ± 0.06; dry swallows: 0.6 ± .0.1; water: 0.67 ± 0.12; solid food: 1.06 ± 0.17, P < 0.001. In experiment 2, there was a pronounced and characteristic increase in amplitude of LES electrical activity during feeding, 0.26 ± 0.1; during fasting, 0.99 ± 0.23; while eating, 0.31 ± 0.1 postprandial, P < 0.001. In conclusion, the beginning and duration of a meal are identified by distinct, easily recognizable changes in the amplitude of LES electrical activity. These changes depend on the type of the substance being swallowed and are most prominent with solid food. Changes in LES electrical activity can potentially be used for automatic eating detection.

Regional differences in cholinergic activity of muscle fibers from the human gastroesophageal junction

1997 ◽  
Vol 272 (6) ◽  
pp. G1321-G1327 ◽  
Author(s):  
H. G. Preiksaitis ◽  
N. E. Diamant
Keyword(s):  
Regional Differences ◽  
Gastroesophageal Junction ◽  
Circular Muscle ◽  
Gastric Fundus ◽  
Isometric Tension ◽  
Cholinergic Activity ◽  
Esophageal Sphincter ◽  
The Right

Muscles of the gastroesophageal junction that contribute to the lower esophageal sphincter (LES) include clasplike semicircular fibers on the right and slinglike oblique gastric fibers on the left. This study examined whether in vitro differences between the sling and clasp muscles could account for the in vivo asymmetry of LES pressure and its cholinergic contribution. Isometric tension was recorded from muscle strips of the sling, clasp, and circular layers of the esophagus and gastric fundus isolated from surgical specimens. The sling developed less spontaneous tension (8.9 +/- 4.3 mN/mm2) than the clasp (25.0 +/- 7.4 mN/mm2, P < 0.01) but showed a fivefold greater increase in response to carbachol. Eserine (1 microM) increased tension in the sling muscle (64.5 +/- 29.7%), but not in the clasp, whereas 1 microM atropine or 1 microM tetrodotoxin had no significant effect in either muscle. In both muscles, tension was reduced by 10 microM sodium nitroprusside. Sling or clasp muscle differed from circular muscle of the esophagus or gastric fundus in spontaneous tension, carbachol response, or responses to electrical stimulation. Thus the clasp muscle develops greater spontaneous tension, whereas the sling is more sensitive to cholinergic stimulation, providing a potential explanation for the in vivo asymmetry of the LES pressure and its response to cholinergic blockade.

scholarly journals Gastric and lower esophageal sphincter pressures during nausea: a study using visual motion-induced nausea and high-resolution manometry

2014 ◽  
Vol 306 (9) ◽  
pp. G741-G747 ◽  
Author(s):  
Nora Schaub ◽  
Kee Ng ◽  
Paul Kuo ◽  
Qasim Aziz ◽  
Daniel Sifrim
Keyword(s):  
High Resolution ◽  
Lower Esophageal Sphincter ◽  
Visual Motion ◽  
Gastroesophageal Junction ◽  
Gastric Fundus ◽  
Vagal Activity ◽  
High Resolution Manometry ◽  
Esophageal Sphincter ◽  
Configuration Changes ◽  
Motion Video

Nausea is the subjective unpleasant sensation that immediately precedes vomiting. Studies using barostats suggest that gastric fundus and lower esophageal sphincter (LES) relaxation precede vomiting. Unlike barostat, high-resolution manometry allows less invasive, detailed measurements of fundus pressure (FP) and axial movement of the gastroesophageal junction (GEJ). Nausea was induced in 12 healthy volunteers by a motion video and rated on a visual analog scale. FP was measured as the mean value of the five pressure channels that were clearly positioned below the LES. After intubation, a baseline (BL) recording of 15 min was obtained. This was followed by presentation of the motion video (at least 10 min, maximum 20 min) followed by 30 min recovery recording. Throughout the experiment we recorded autonomic nervous system (ANS) parameters [blood pressure, heart rate (HR), and cardiac vagal tone (CVT), which reflects efferent vagal activity]. Ten out of 12 subjects showed a drop in FP during peak nausea compared with BL (−4.0 ± 0.8 mmHg; P = 0.005), and 8/10 subjects showed a drop in LES pressure (−8.8 ± 2.5 mmHg; P = 0.04). Peak nausea preceded peak fundus and LES pressure drop. Nausea was associated with configuration changes at the GEJ such as LES shortening and esophageal lengthening. During nausea we observed a significantly increased HR and decreased CVT. In conclusion, nausea is associated with a drop in fundus and LES pressure, configuration changes at the GEJ as well as changes in the ANS activity such as an increased sympathetic tone (increased HR) and decreased parasympathetic tone (decreased CVT).

Stimulus-dependent pacemaker activity in the distal canine lower esophageal sphincter

1989 ◽  
Vol 67 (10) ◽  
pp. 1331-1335 ◽  
Author(s):  
P. D. Walton ◽  
J. D. Huizinga
Keyword(s):  
Lower Esophageal Sphincter ◽  
Calcium Influx ◽  
Contractile Activity ◽  
Potassium Conductance ◽  
Slow Waves ◽  
Pacemaker Activity ◽  
Direct Excitation ◽  
Esophageal Sphincter ◽  
Spiking Activity

Electrical and mechanical properties of the distal canine lower esophageal sphincter were studied in vitro to investigate possible means of inducing pacemaker activity. Both direct excitation and block of potassium conductance were investigated. The acetylcholine analog, carbachol, induced tissue depolarization and increase in tone but no electrical slow waves. Tetra-ethylammonium (TEA) chloride induced depolarization and evoked continuous spiking activity and increase in tone. BaCl did not depolarize the tissue but low amplitude spiking activity developed and increased tone. The putative potassium channel blocker, aminacrine at 2 × 10−4 M, induced electrical slow wave activity in the distal lower esophageal sphincter, with or without superimposed spikes, accompanied by phasic contractile activity. This activity closely resembled the spontaneous pacemaker activity observed previously in the proximal lower esophageal sphincter. The aminacrine-induced activity was abolished by calcium influx blockers. Aminacrine, but not TEA or BaCl, abolished the nonadrenergic nerve-mediated inhibitory junction potentials. In conclusion, block of inhibitory innervation, and induction of electrical slow waves as a control mechanism for phasic contractile activity, seems to require blockade of an aminacrine- but not TEA-sensitive potassium conductance.Key words: smooth muscle, potassium conductance, slow waves, aminacrine, lower esophageal sphincter.

Simultaneous reflex inhibition of lower esophageal sphincter and crural diaphragm in cats

1985 ◽  
Vol 249 (5) ◽  
pp. G586-G591 ◽  
Author(s):  
S. M. Altschuler ◽  
J. T. Boyle ◽  
T. E. Nixon ◽  
A. I. Pack ◽  
S. Cohen
Keyword(s):  
Lower Esophageal Sphincter ◽  
Gastroesophageal Junction ◽  
Pressure Profile ◽  
Gastric Fundus ◽  
Intraluminal Pressure ◽  
Neural Pathways ◽  
Balloon Distension ◽  
Esophageal Sphincter ◽  
Crural Diaphragm ◽  
High Pressure Zone

We have previously suggested that both the lower esophageal sphincter and diaphragm contribute to the high-pressure zone (HPZ) at the gastroesophageal junction. The purpose of this study in anesthetized cats was to compare changes in diaphragmatic electrical activity with changes in the intraluminal pressure profile in the HPZ following either balloon distension of the esophagus or swallowing evoked by pharyngeal stimulation. Intraluminal pressure was continuously recorded by a perfused manometric assembly anchored to the gastric fundus through an abdominal surgical approach. Integrated EMG was simultaneously measured in the costal and crural parts of the diaphragm. Our results indicate that simultaneous relaxation of the lower esophageal sphincter (LES) and crural diaphragm follows both swallowing and balloon distension of the esophagus; during swallowing both inhibitory reflexes depend on the initiation of esophageal peristalsis; crural relaxation abolishes respiratory-induced pressure oscillations in the HPZ during LES relaxation; ventilation is maintained during relaxation of the HPZ in part by continued contraction of the costal diaphragm; and different neural pathways control LES relaxation and crural relaxation. The data support the view that the crural diaphragm augments the intrinsic smooth muscle sphincter mechanism at the gastroesophageal junction and that crural relaxation may be an important factor in mouth-to-gastric transit.

Neuropeptide Y augments adrenergic contractions at feline lower esophageal sphincter

1989 ◽  
Vol 256 (3) ◽  
pp. G589-G597 ◽  
Author(s):  
H. P. Parkman ◽  
J. C. Reynolds ◽  
C. P. Ogorek ◽  
K. M. Kicsak
Keyword(s):  
Tyrosine Hydroxylase ◽  
Neuropeptide Y ◽  
Lower Esophageal Sphincter ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Gastric Fundus ◽  
Muscularis Mucosa ◽  
Biphasic Effect ◽  
Esophageal Sphincter

The purpose of this study was to determine the anatomic and physiological interactions between neuropeptide Y (NPY) and adrenergic transmitters at the feline lower esophageal sphincter (LES). Intraluminal pressures of the esophagus, LES, and gastric fundus were recorded in anesthetized cats. In a separate group of cats, gastroesophageal junctions were removed after locating the LES manometrically. Adjacent sections were stained with antibodies for NPY and tyrosine hydroxylase (TH). Indirect immunofluorescence revealed staining of TH- and NPY-like immunoreactive (LI) nerves in the circular muscle of the LES. Staining was also present for NPY-LI in longitudinal muscle, muscularis mucosa, periarterial nerves, and nerves and cell bodies of the myenteric plexus of the LES. In vivo, NPY produced a biphasic effect at the LES with an initial contraction (lasting approximately 30 s) followed by a relaxation (lasting approximately 3 min). NPY at the dose giving 50% of the maximum response (10(-6) g/kg) induced a contraction of 14.8 +/- 5.0 mmHg (P less than 0.05) followed by a decrease of basal LES pressure from 29.2 +/- 4.7 to 19.4 +/- 2.9 mmHg (P less than 0.01). Propranolol and phentolamine had no influence on either effect of NPY.(ABSTRACT TRUNCATED AT 250 WORDS)

Esophageal longitudinal muscle contraction: Another component of transient lower esophageal sphincter relaxation (tLESR)?

2001 ◽  
Vol 120 (5) ◽  
pp. A632
Author(s):  
Guoxiang Shi ◽  
John E. Pandolfino ◽  
Raymond J. Joehl ◽  
James G. Brassuer ◽  
Peter J. Kahrilas
Keyword(s):  
Muscle Contraction ◽  
Lower Esophageal Sphincter ◽  
Longitudinal Muscle ◽  
Lower Esophageal Sphincter Relaxation ◽  
Esophageal Sphincter

Esophageal manometry in the opossum.

1977 ◽  
Vol 233 (3) ◽  
pp. E152
Author(s):  
K Schulze ◽  
W J Dodds ◽  
J Christensen ◽  
J D Wood
Keyword(s):  
Animal Model ◽  
Lower Esophageal Sphincter ◽  
Esophageal Manometry ◽  
Lower Esophageal Sphincter Pressure ◽  
Upper Esophageal Sphincter ◽  
Sphincter Pressure ◽  
Coronal Section ◽  
Esophageal Sphincter ◽  
Human Esophagus

The opossum esophagus is commonly used as an animal model of the human esophagus. We used esophageal manometry in normal animals to provide basal data about normal esophageal motor functions in vivo in this species. At rest, separate and distinct high pressure zones can be recorded at the level of the lower esophageal sphincter, diaphragmatic hiatus, aortic arch, and upper esophageal sphincter. Each zone demonstrates a characteristic pattern of pressures in the radii of the coronal section and a characteristic response to swallowing. The hiatal and aortic zones can be mistaken for the esophageal sphincters. Pressures in the sphincters fall with swallowing. Peristalsis is not bolus-dependent and occurs with 98% of swallows. Pressures generated by peristalsis are greater in the middle of the esophagus than at the ends. Values for resting lower esophageal sphincter pressure and the characteristics of peristalsis were reproducible between different studies in the same animals.

Chronic electrical activity of cat intestine

1984 ◽  
Vol 246 (4) ◽  
pp. G335-G341 ◽  
Author(s):  
A. Bortoff ◽  
L. F. Sillin ◽  
A. Sterns
Keyword(s):  
Electrical Activity ◽  
Slow Waves ◽  
Intestinal Anastomoses ◽  
Bipolar Electrodes ◽  
Spontaneous Electrical Activity ◽  
Central Origin ◽  
Variable Duration

Spontaneous electrical activity was recorded with bipolar electrodes from the gastrointestinal tracts of unanesthetized fasted cats (upper and lower cut-off frequencies: 35 and 3 Hz). In addition to slow waves (SWs) and spike potentials (SPs), the following three patterns of activity were recorded that are not observed in vitro. 1) Intense bursts of SPs (migrating spike complexes, MSCs) migrate caudally at a velocity of approximately 1 mm/s. MSCs resemble migrating myoelectric complexes (MMCs) in their velocity and by their traversal of intestinal anastomoses. SWs are usually suppressed during and immediately after the MSC, and, on their return, propagate at a higher velocity than they do prior to the MSC. Unlike its effect on MMCs, motilin does not appear to elicit MSCs, a finding consistent with the fact that MSCs occur infrequently in the duodenum and not at all in the antrum. 2) Bursts of SPs are found in the absence of recorded SWs. The SP bursts are of variable duration and occur virtually simultaneously at several recording sites, or propagate at 1-2 cm/s in either direction along the jejunum. The more usual caudally propagating SPs occur when SWs reappear. 3) "Minute rhythms," periods of spiking SWs, occur simultaneously over long lengths of upper bowel, sometimes including antrum, at intervals of about 1-2 min. It is proposed that, despite their differences, the cat MSC may be the functional counterpart of the MMC, that cat SWs are not omnipresent, and that the minute rhythms described here are of central origin.

Identification of longitudinal muscle activity in opossum lower esophageal sphincter

1991 ◽  
Vol 261 (6) ◽  
pp. G974-G980 ◽  
Author(s):  
S. S. Harrington ◽  
W. J. Dodds ◽  
R. K. Mittal
Keyword(s):  
Muscle Contraction ◽  
Lower Esophageal Sphincter ◽  
Strain Gauge ◽  
Longitudinal Muscle ◽  
Pressure Fluctuations ◽  
Circular Muscle ◽  
Pharmacological Agents ◽  
Esophageal Sphincter ◽  
High Pressure Zone ◽  
Contraction And Relaxation

The aim of this study was to characterize lower esophageal sphincter (LES) longitudinal muscle contraction during changes in LES pressure in opossums. LES pressure was used as a marker of LES circular muscle contraction. Longitudinal muscle contraction was measured by strain gauge transducers. For precise placement of the strain gauge on the LES, the high-pressure zone was identified using a manometric-laser illumination technique. Measurements were made during 1) spontaneous LES pressure fluctuations, 2) LES pressure changes induced by pharmacological agents, and 3) LES relaxation induced by vagal nerve stimulation. These studies show that 1) spontaneous LES pressure fluctuations correlated with spontaneous changes in LES longitudinal muscle contraction; 2) pharmacologically induced contraction and relaxation of LES pressure correlated with contraction and relaxation of LES longitudinal muscle, respectively; 3) a close temporal relationship existed between changes in LES longitudinal muscle contraction and LES pressure that occurred spontaneously or were induced pharmacologically; and 4) vagal stimulation caused LES longitudinal muscle contraction and LES pressure relaxation. We propose that LES longitudinal muscle may play a role in the modulation of intraluminal LES pressure.

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