[Gastrointestinal hormones and lower esophageal sphincter]

In the gastroesophageal closing mechanism there is a digestive sphincter which as yet has only been identified by its function. This sphincter is subject to the action of gastrointestinal hormones; all hormones, except gastrin and possibly motilin have a relaxing effect. This action sets in only following administration of relatively large doses and thus corresponds to pharmacological effects. The physiological effect of gastrin long under discussion could not be proved in these tests - at least not for antral G 17. Whether or to what extent other hormones - perhaps Big gastrin - have an effect on the control of the lower esophageal sphincter under normal conditions remains yet to be determined.