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.

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

A Unique Longitudinal Muscle Contraction Pattern Associated With Transient Lower Esophageal Sphincter Relaxation

2008 ◽  
Vol 134 (5) ◽  
pp. 1322-1331 ◽  
Author(s):  
Arash Babaei ◽  
Valmik Bhargava ◽  
Hariprasad Korsapati ◽  
Wei Hao Zheng ◽  
Ravinder K. Mittal
Keyword(s):  
Muscle Contraction ◽  
Lower Esophageal Sphincter ◽  
Longitudinal Muscle ◽  
Contraction Pattern ◽  
Lower Esophageal Sphincter Relaxation ◽  
Esophageal Sphincter

scholarly journals Pressure morphology of the relaxed lower esophageal sphincter: the formation and collapse of the phrenic ampulla

2012 ◽  
Vol 302 (3) ◽  
pp. G389-G396 ◽  
Author(s):  
Monika A. Kwiatek ◽  
Frédéric Nicodème ◽  
John E. Pandolfino ◽  
Peter J. Kahrilas
Keyword(s):  
Lower Esophageal Sphincter ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Radial Pressure ◽  
Normal Subjects ◽  
Baseline Length ◽  
Bolus Transit ◽  
Yield Zone ◽  
High Resolution Manometry ◽  
Esophageal Sphincter

This study aimed to apply novel high-resolution manometry with eight-sector radial pressure resolution (3D-HRM technology) to resolve the deglutitive pressure morphology at the esophagogastric junction (EGJ) before, during, and after bolus transit. A hybrid HRM assembly, including a 9-cm-long 3D-HRM array, was used to record EGJ pressure morphology in 15 normal subjects. Concurrent videofluoroscopy was used to relate bolus movement to pressure morphology and EGJ anatomy, aided by an endoclip marking the squamocolumnar junction (SCJ). The contractile deceleration point (CDP) marked the time at which luminal clearance slowed to 1.1 cm/s and the location (4 cm proximal to the elevated SCJ) at which peristalsis terminated. The phrenic ampulla spanned from the CDP to the SCJ. The subsequent radial and axial collapse of the ampulla coincided with the reconstitution of the effaced and elongated lower esophageal sphincter (LES). Following ampullary emptying, the stretched LES (maximum length 4.0 cm) progressively collapsed to its baseline length of 1.9 cm ( P < 0.001). The phrenic ampulla is a transient structure comprised of the stretched, effaced, and axially displaced LES that serves as a “yield zone” to facilitate bolus transfer to the stomach. During ampullary emptying, the LES circular muscle contracts, and longitudinal muscle shortens while that of the adjacent esophagus reelongates. The likely LES elongation with the formation of the ampulla and shortening to its native length after ampullary emptying suggest that reduction in the resting tone of the longitudinal muscle within the LES segment is a previously unrecognized component of LES relaxation.

Gap junctions in gastrointestinal muscle contain multiple connexins

2001 ◽  
Vol 281 (2) ◽  
pp. G533-G543 ◽  
Author(s):  
Y. F. Wang ◽  
E. E. Daniel
Keyword(s):  
Gastrointestinal Tract ◽  
Gap Junctions ◽  
Lower Esophageal Sphincter ◽  
Myenteric Plexus ◽  
Interstitial Cells Of Cajal ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Esophageal Sphincter ◽  
Cells Of Cajal ◽  
Cx 43

In the canine gastrointestinal tract, the roles that gap junctions play in pacemaking and neurotransmission are unclear. Using antibodies to connexin (Cx)43, Cx45, and Cx40, we determined the distribution of these connexins. Cx43 was present in all locations where structural gap junctions occur. Cx40 was also widely distributed in the circular muscle of the lower esophageal sphincter (LES), stomach, and ileum. Cx45 was sparsely distributed in circular muscle of the LES. In the interstitial cells of Cajal (ICC) networks of myenteric plexus, in the deep muscular and submuscular plexuses, sparse Cx45 and Cx40 immunoreactivity was present. In colon, immunoreactivity was found only in the myenteric and submuscular plexus and nearby circular muscle cells. No immunoreactivity was found in sites lacking structural gap junctions (longitudinal muscle, inner circular muscle of the intestine, and most circular muscle of the colon). Studies of colocalization of connexins suggested that in the ICC networks, some colocalization of Cx43 with Cx40 and/or Cx45 occurred. Thus gap junctions in canine intestine may be heterotypic or heteromeric and have different conductance properties in different regions based on different connexin compositions.

scholarly journals Circular and longitudinal muscles shortening indicates sliding patterns during peristalsis and transient lower esophageal sphincter relaxation

2015 ◽  
Vol 309 (5) ◽  
pp. G360-G367 ◽  
Author(s):  
Nirali Patel ◽  
Yanfen Jiang ◽  
Ravinder K. Mittal ◽  
Tae Ho Kim ◽  
Melissa Ledgerwood ◽  
...  
Keyword(s):  
Lower Esophageal Sphincter ◽  
Animal Studies ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Esophageal Sphincter ◽  
And Function ◽  
Longitudinal Muscles ◽  
Histology And Immunohistochemistry ◽  
Esophageal Contraction ◽  
Axial Shortening

Esophageal axial shortening is caused by longitudinal muscle (LM) contraction, but circular muscle (CM) may also contribute to axial shortening because of its spiral morphology. The goal of our study was to show patterns of contraction of CM and LM layers during peristalsis and transient lower esophageal sphincter (LES) relaxation (TLESR). In rats, esophageal and LES morphology was assessed by histology and immunohistochemistry, and function with the use of piezo-electric crystals and manometry. Electrical stimulation of the vagus nerve was used to induce esophageal contractions. In 18 healthy subjects, manometry and high frequency intraluminal ultrasound imaging during swallow-induced esophageal contractions and TLESR were evaluated. CM and LM thicknesses were measured (40 swallows and 30 TLESRs) as markers of axial shortening, before and at peak contraction, as well as during TLESRs. Animal studies revealed muscular connections between the LM and CM layers of the LES but not in the esophagus. During vagal stimulated esophageal contraction there was relative movement between the LM and CM. Human studies show that LM-to-CM (LM/CM) thickness ratio at baseline was 1. At the peak of swallow-induced contraction LM/CM ratio decreased significantly (<1), whereas the reverse was the case during TLESR (>2). The pattern of contraction of CM and LM suggests sliding of the two muscles. Furthermore, the sliding patterns are in the opposite direction during peristalsis and TLESR.

scholarly journals A novel pattern of longitudinal muscle contraction with subthreshold pharyngeal stimulus: a possible mechanism of lower esophageal sphincter relaxation

2012 ◽  
Vol 302 (5) ◽  
pp. G542-G547 ◽  
Author(s):  
Eric Leslie ◽  
Valmik Bhargava ◽  
Ravinder K. Mittal
Keyword(s):  
Muscle Contraction ◽  
Lower Esophageal Sphincter ◽  
Motor Neurons ◽  
Longitudinal Muscle ◽  
Upper Esophageal Sphincter ◽  
Distal Esophagus ◽  
High Resolution Manometry ◽  
Proximal Esophagus ◽  
Strong Contraction ◽  
Esophageal Sphincter

A subthreshold pharyngeal stimulus induces lower esophageal sphincter (LES) relaxation and inhibits progression of ongoing peristaltic contraction in the esophagus. Recent studies show that longitudinal muscle contraction of the esophagus may play a role in LES relaxation. Our goal was to determine whether a subthreshold pharyngeal stimulus induces contraction of the longitudinal muscle of the esophagus and to determine the nature of this contraction. Studies were conducted in 16 healthy subjects. High resolution manometry (HRM) recorded pressures, and high frequency intraluminal ultrasound (HFIUS) images recorded longitudinal muscle contraction at various locations in the esophagus. Subthreshold pharyngeal stimulation was induced by injection of minute amounts of water in the pharynx. A subthreshold pharyngeal stimulus induced strong contraction and caudal descent of the upper esophageal sphincter (UES) along with relaxation of the LES. HFIUS identified longitudinal muscle contraction of the proximal (3–5 cm below the UES) but not the distal esophagus. Pharyngeal stimulus, following a dry swallow, blocked the progression of dry swallow-induced peristalsis; this was also associated with UES contraction and descent along with the contraction of longitudinal muscle of the proximal esophagus. We identify a unique pattern of longitudinal muscle contraction of the proximal esophagus in response to subthreshold pharyngeal stimulus, which we propose may be responsible for relaxation of the distal esophagus and LES through the stretch sensitive activation of myenteric inhibitory motor neurons.

scholarly journals Cholecystokinin induces esophageal longitudinal muscle contraction and transient lower esophageal sphincter relaxation in healthy humans

2018 ◽  
Vol 315 (5) ◽  
pp. G734-G742 ◽  
Author(s):  
Arash Babaei ◽  
Ravinder Mittal
Keyword(s):  
Muscle Contraction ◽  
Lower Esophageal Sphincter ◽  
Motor Neurons ◽  
Longitudinal Muscle ◽  
Muscle Thickness ◽  
Phase 2 ◽  
Healthy Humans ◽  
Inhibitory Motor Neurons ◽  
Esophageal Sphincter ◽  
Crural Diaphragm

Cholecystokinin (CCK) is known to cause lower esophageal sphincter (LES) relaxation through the activation of inhibitory motor neurons. CCK receptor agonists increase the frequency of transient LES relaxation through a peripheral mechanism. Recent studies show that the longitudinal muscle contraction (LMC)-related axial stretch might play a role in the LES relaxation by activating the mechanosensitive inhibitory motor neurons. The aim of our study was to determine whether the CCK-induced LES relaxation and the characteristics of LMC resemble those seen with spontaneous transient LES relaxation in humans. Nine healthy volunteers (5 Fr, 40 ± 12 yr) received escalating doses of CCK-octapeptide (CCK-8) (5, 10, 20, and 40 ng/kg). All subjects demonstrated a monophasic response to 5 ng/kg of CCK-8. In the majority of subjects, this response consisted of partial LES relaxation. All subjects showed a biphasic response to 40 ng/kg of CCK-8. The latter in most subjects consisted of 1) a period of partial relaxation followed by 2) complete LES relaxation along with crural diaphragm inhibition. The length of the esophagus decreased by 0.9 ± 0.4 cm, and muscle thickness increased by 40 ± 14% to 1.4 ± 0.2 mm ( P < 0.05) during initial partial LES relaxation. During complete LES relaxation there was greater LMC, as demonstrated by an esophageal shortening of 1.9 ± 0.5 cm and an increase in muscle thickness of 100 ± 16% ( P < 0.01). The complete phase 2 LES relaxation typically terminated with a robust after-contraction. Atropine significantly attenuated the CCK-induced esophageal LMC, prevented crural diaphragm inhibition, and abolished the phase 2 complete LES relaxation.NEW & NOTEWORTHY The phenotypic features of CCK-induced longitudinal muscle contraction (LMC), complete lower esophageal sphincter (LES) relaxation, and crural diaphragm inhibition, followed by a robust after-contraction, resemble those seen during spontaneous transient LES relaxation. A strong temporal relationship between the LMC and complete transient LES relaxation supports our hypothesis that the LMC plays an important role in the LES relaxation and crural diaphragmatic inhibition.

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)

Sign in / Sign up

Export Citation Format

Share Document