Regulation Of Motilin, Gastrin And Cholecystokinin On The Human Lower Esophageal Sphincter

The existence and structural equivalent of the lower esophageal sphincter (LES) in human beings have been a matter of speculation for many years. After studying the anatomy of 32 cadavers, Liebermann-Meffert et al described the arrangement of the smooth muscles at the esophagogastric junction (EGJ) in detail. They demonstrated that the musculature of the human LES consisted of sling fibers at the greater curvature and clasp fibers at the lesser curvature. This theory laid the foundation for further studies on the physiology, pathology and pharmacology of the LES. The human LES is a unique one-way valve, which remains closed to prevent reflux of gastric contents into the esophagus all the time except for temporary relaxation to permit passage of food from the esophagus into the stomach or to vomit and hiccup. Thus, the structural or functional abnormality in the human LES may result in a number of disorders.Over the ensuing years, many studies on the physiological feature and functional regulation of the LES in several kinds of animals were extensively conducted. These studies have suggested that the muscular system of the LES has different characteristics compared with other smooth muscular structures, and the most important is that the sling fibers and clasp fibers forming the LES varied significantly in many aspects. Therefore, further investigation of the LES is definitely necessary for a better understanding of the etiology and pathology of LES-related disorders, and helpful for the choice of treatment for esophageal motility diseases including achalasia, the hypertensive lower esophageal sphincter, and gastroesophageal reflux disease (GERD).The LES is the most important element forming the esophagogastric junction and its functional ragulation is very sophisticated, in which neuvous system, humoral system and spontaneous myogenic factors are all involved.