Lower Esophageal Sphincter Pressure Changes After Food Ingestion

Abstract

The primary function of the lower esophageal sphincter is to prevent reflux of gastric contents into the esophagus. Therefore, changes in lower esophageal sphincter strength after the ingestion of various foods should be of considerable interest. Pressure in the lower esophageal sphincter was recorded continuously in normal subjects using an infused open-tipped system. Test meals consisted of equicaloric quantities of either protein, carbohydrate, or fat in a total volume of 150 cc. After ingestion of ground beef, consistent increases in lower esophageal sphincter pressure were recorded. This effect was eradicated by acidifying the ground meat meal to a pH of 1.2 to 1.3. After glucose ingestion, slight but significant increases in lower esophageal sphincter pressure were found. By contrast, ingestion of a corn oil meal resulted in a decrease in lower esophageal sphincter pressure. Even greater decreases in lower esophageal sphincter were produced by intraduodenal fat. Intraduodenal acidification and exogenous secretin resulted in minimal decreases in sphincter pressure, with much greater decreases in pressure noted after subsequent intraduodenal instillation of fat. The increased pressure after protein and its inhibition by acidification suggest a mechanism through antral gastrin release; the slight rise in pressure after glucose may indicate a minimal gastrin effect, and the pressure decreases following a fat meal most likely are produced by an entero- gastrone other than secretin.