Effect of duodenal acidification on the lower esophageal sphincter pressure in the dog with special reference to related gastrointestinal hormones.

The role of the duodenum in the regulation of the lower esophageal sphincter pressure was studied in 3 anesthetized dogs with a duodenal fistula by relating the lower esophageal sphincter pressure with plasma gastrin and secretin level during intraduodenal acid infusion test. Instillation of hydrochloric acid into the duodenum produced an initial fall followed by a significant and sustained increase of the lower esophageal sphincter pressure. The initial fall of the lower esophageal sphincter pressure was found to correspond to a prompt but transient rise of plasma secretin concentration, while plasma gastrin did not change significantly throughout the experimental period. It is concluded that duodenum may be an important regulator of the lower esophageal sphincter pressure in the dog through secretin and other unknown factors.