Secretin-stimulated serum gastrin levels in hyperparathyroid patients from families with multiple endocrine adenomatosis type I.

Twenty-three patients with hyperparathyroidism from six families with the multiple endocrine adenomatosis (MEA) I-syndrome were tested by secretin provocation. In nine cases this led to increases in serum gastrin ranging from 298 to 13 300 pg/ml, whereas the maximum rise in gastrin in the other 14 patients was 32 pg/ml. In all nine patients with marked gastrin responses to secretin, the Zollinger-Ellison syndrome was diagnosed by gastric acid hypersecretion and large increases in gastrin after calcium administration. Six of these nine patients had, at most, minor postprandial rises in gastin and two had demonstrable tumors. In 34 normal subjects, 23 nonaffected members of families with MEA I-syndrome, and 42 patients with various diseases the maximum gastrin response to secretin was 21 pg/ml. We conclude that secretin provocation is helpful in the diagnosis of the Zollinger-Ellison syndrome, especially when basal serum gastrin levels are only slightly elevated.