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Mechanism of UES relaxation initiated by gastric air distension. Am J Physiol Gastrointest Liver Physiol 2014 Aug 15;307(4):G452-8

Date

06/28/2014

Pubmed ID

24970778

Pubmed Central ID

PMC4137114

DOI

10.1152/ajpgi.00120.2014

Scopus ID

2-s2.0-84907960406   8 Citations

Abstract

The aim of this study was to determine the mechanism of initiation of transient upper esophageal sphincter relaxation (TUESR) caused by gastric air distension. Cats (n = 31) were decerebrated, EMG electrodes were placed on the cricopharyngeus, a gastric fistula was formed, and a strain gauge was sewn on the lower esophageal sphincter (n = 8). Injection of air (114 ± 13 ml) in the stomach caused TUESR (n = 18) and transient lower esophageal sphincter relaxation (TLESR, n = 6), and this effect was not significantly (P > 0.05) affected by thoracotomy. Free air or bagged air (n = 6) activated TLESR, but only free air activated TUESR. Closure of the gastroesophageal junction blocked TUESR (9/9), but not TLESR (4/4), caused by air inflation of the stomach. Venting air from distal esophagus during air inflation of the stomach prevented TUESR (n = 12) but did not prevent air escape from the stomach to the esophagus (n = 4). Rapid injection of air on the esophageal mucosa always caused TUESR (9/9) but did not always (7/9) cause an increase in esophageal pressure. The time delay between the TUESR and the rapid air pulse was significantly more variable (P < 0.05) than the time delay between the rapid air pulse and the rise in esophageal pressure. We concluded that the TUESR caused by gastric air distension is dependent on air escape from the stomach, which stimulates receptors in the esophagus, but is not dependent on distension of the stomach or esophagus, or the TLESR. Therefore, the TUESR caused by gastric air distension is initiated by stimulation of receptors in the esophageal mucosa.

Author List

Lang IM, Medda BK, Shaker R

Authors

Ivan M. Lang DVM, PhD Professor in the Medicine department at Medical College of Wisconsin
Bidyut K. Medda PhD Associate Professor in the Medicine department at Medical College of Wisconsin
Reza Shaker MD Assoc Provost, Sr Assoc Dean, Ctr Dir, Chief, Prof in the Medicine department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Air
Animals
Cats
Decerebrate State
Electromyography
Eructation
Esophageal Sphincter, Lower
Esophageal Sphincter, Upper
Esophagogastric Junction
Mechanoreceptors
Muscle Relaxation
Pressure
Stomach
jenkins-FCD Prod-411 e00897e83867fcfa48419861683711f8d99adb75