Lower Esophageal Sphincter Motility Assays
The lower esophageal sphincter (LES) is a critical component of the digestive system, serving as one of the primary anti-reflux barriers that protect the esophagus from the backflow of gastric contents. This specialized segment of circular muscle, located at the esophago-gastric junction, plays a key role in regulating food transit from the esophagus into the stomach while preventing gastroesophageal reflux.1
A dysfunctional or weakened LES can lead to several disorders, including gastroesophageal disease (GERD), Barrett’s esophagus, and achalasia. GERD is the most common LES disorder, occurring when the sphincter weakens or relaxes inappropriately, allowing stomach acid to flow back into the esophagus. This backflow causes symptoms such as heartburn and regurgitation and if prolonged, increases the risk of esophageal metaplasia and esophageal adenocarcinoma. Barrett’s esophagus, often a complication of chronic GERD, occurs when repeated acid exposure damages the esophageal lining, causing it to change into a tissue type similar to that of the intestine. This condition significantly increases the risk of esophageal cancer. Another disorder, achalasia, is a rarer condition in which the LES fails to relax properly, preventing food and liquids from passing easily into the stomach. Along with difficulty swallowing (dysphagia), achalasia can cause regurgitation and chest pain. Understanding these disorders is essential for early diagnosis and effective management.2, 3, 4
Anatomy and Function of the Lower Esophageal Sphincter
The junction between the esophagus and the stomach is a complex region composed of:
- The lower esophageal sphincter: responsible for maintaining 90% of the basal pressure at the esophago-gastric junction.
- The gastric sling fibers: contributing to LES tone and function.
- The crural diaphragm: working in conjunction with the LES to enhance its barrier function.
Together these structures coordinate to allow ingested food to pass into the stomach smoothly and prevent the reflux of acidic gastric contents into the esophagus.
Why Lower Esophageal Sphincter Motility Matters in Drug Discovery
LES motility disorders are linked to conditions such as GERD, achalasia and esophageal dysmotility syndromes. Understanding the mechanisms behind LES function and dysfunction is essential for developing new therapeutic interventions aimed at improving esophageal motility and reducing reflux-related complications.5
At REPROCELL we specialize in ex vivo human tissue assays to assess LES motility and function, providing clinically relevant insights for drug discovery. Contact us today to learn more about our LES motility assays and how we can support your research in gastroesophageal disorders.
References:
1. Sidhu AS, Triadafilopoulos G. Neuro-regulation of lower esophageal sphincter function as treatment for gastroesophageal reflux disease. World J Gastroenterol. 2008 Feb 21;14(7):985-90. doi: 10.3748/wjg.14.985. PMID: 18286675; PMCID: PMC2689423.
2. Hershcovici T, Mashimo H, Fass R. The lower esophageal sphincter. Neurogastroenterol Motil. 2011 Sep;23(9):819-30. doi: 10.1111/j.1365-2982.2011.01738.x. Epub 2011 Jun 29. PMID: 21711416.
3. Hayat, Jamal Omar, et al. “Achalasia.” Achalasia - Symptoms, Diagnosis and Treatment | BMJ Best Practice US, bestpractice.bmj.com/topics/en-gb/872. Accessed 24 Mar. 2025.
4. Haidry, Rehan. “Barrett’s Oesophagus: Symptoms, Causes and Treatment | BUPA UK.” Barrett’s Oesophagus, www.bupa.co.uk/health-information/digestive-gut-health/barretts-oesophagus. Accessed 24 Mar. 2025.
5. Boeckxstaens GE. The lower oesophageal sphincter. Neurogastroenterol Motil. 2005 Jun;17 Suppl 1:13-21. doi: 10.1111/j.1365-2982.2005.00661.x. PMID: 15836451.
