Serum gastrin in health and disease.

Recent developments have led to a further appreciation of the various species of circulating gastrin and to provocative tests for the presence of the Zollinger-Ellison syndrome. Studies of serum gastrin levels, together with other studies of physiologic response, have suggested some possible roles of gastrin in the complex gastric acid hypersecretory state that frequently accompanies duodenal ulcer. Finally, investigations of exogenous and endogenous serum gastrin have provided a mechanism to examine the possible physiologic effects of this hormone.