Effect of gastrointestinal hormone infusions on lower oesophageal competence of Rhesus monkeys

The lower oesophageal high pressure zone (HPZ) was studied in 5 non-refluxing and 3 refluxing Rhesus monkeys. The changes in HPZ and reflux status in response to infusion of various doses of secretin, cholecystokinin and glucagon were measured in all animals, and, in the 5 non-refluxing monkeys, after oesophagogastrectomy with replacement of the lower oesophagus by a stomach tube. All three hormones consistently produced a transient decrease in the HPZ pressure. The only change in response following oesophagogastrectomy and gastric tube replacement was a significant delay in the response to each hormone. Neither hormone infusion nor operation altered gastro-oesophageal reflux status. It appears that lower oesophageal competence in primates is more dependent on the presence of a narrow, muscular, intra-abdominal tube than on a specialized segment of the lower oesophagus.