Zollinger-Ellison syndrome: 1. Paradoxical postprandial inhibition of gastric secretion1

The gastric acid, pepsin, and secretory volume output in response to a mixed meal were measured in six patients with Zollinger-Ellison syndrome caused by a gastrin-producing tumour proved subsequently at surgery. The patients were all normocalcaemic, and none had previous abdominal surgery. In four of the six patients, ingestion of the meal markedly inhibited the gastric secretory output, which decreased to below fasting levels, returning later to basal values. In two other patients, whose fasting acid output was considerably lower, the secretory output increased after the meal, but some inhibition of gastric secretion was also apparent for variable intervals of time. The serum gastrin concentration in all patients remained essentially unchanged or increased after the meal. Two patients were restudied after successful removal of the duodenal gastrin-producing tumour, and in each the normal gastric secretory and gastrin-releasing