Effect of intraduodenal peptone on the lower esophageal sphincter pressure in the dog.

The role of the duodenum in the regulation of the lower esophageal sphincter pressure (LESP) was investigated in 4 unrestrained dogs equipped with a chronic Komarov type esophagostomy, a cutaneous duodenal fistula, a gastrojejunostomy, and a Y anastomosis between the distal end of the duodenum and the midjejunum. Installation of NaCl solution into the duodenum or into the stomach did not effect LESP during the following 60-min observation period. Peptone instillation into the duodenum or into the stomach produced a sustained elevation LESP. The rise of LESP was significantly greater after duodenal than after gastric instillation. Duodenal peptone did not raise serum gastrin. It is concluded that the duodenum may be an important regulator of LESP in the dog and that this effect is not mediated by circulating gastrin.