Abnormal pancreatic polypeptide release by secretin infusion in Zollinger-Ellison syndrome

In 28 patients with the Zollinger-Ellison syndrome (ZES), 26 studied before and two after tumor excision, and in 26 age-matched control patients with duodenal ulcer (DU), plasma pancreatic polypeptide and serum gastrin concentrations were studied before, during, and after infusion of pure secretin (3 CU/kg/hr). In 21 ZES patients, gastric acid output was simultaneously studied. Fasting pancreatic polypeptide concentrations were over 300 pmol/liter in five of 26 gastrinomas. In DU, secretin caused a nonsignificant increase in plasma pancreatic polypeptide concentration and markedly decreased gastric acid output. In ZES, however, it resulted in a marked increase of both plasma pancreatic polypeptide concentration and gastric acid output. Basal and post secretin pancreatic polypeptide concentrations showed no correlation with gastric acid output, serum gastrin levels, or the age of the subjects, in DU patients as well as in ZES. These concentrations were not different in ZES patients who had a vagotomy compared to nonvagotomized ZES patients. Furthermore, the pancreatic polypeptide response to intravenous secretin was abolished by gastrinoma excision.