Serum gastrin levels in response to exogenous secretin in patients with duodenal ulcer--false positive response occurring in case of endoscopically active ulcer.

Responses of serum gastrin to both intravenous infusion of secretin (GIH secretin 3 CU/kg/hr) and intravenous bolus injection (GIH secretin 1 CU/kg) were studied in 2 Zollinger-Ellison syndrome (ZE) patients and 27 duodenal ulcer (DU) patients. In all of the DU patients, the stage of the ulcer was determined endoscopically, prior to testing, as either active or healed. We found that the responses of serum gastrin to secretin were closely related to the stage of the duodenal ulcer; serum gastrin increased in the active stage and decreased in the healed stage. In patients with active duodenal ulcer, a false positive (ZE-like) response to exogenous secretin was observed. Comparing the results of intravenous infusion and bolus administration of secretin in terms of maximal percent change of serum gastrin, there was no significant difference between the two methods, confirming the works reported by others.