Serum gastrins in Zollinger-Ellison syndrome: identification of localized disease.

We determined the relative concentrations of gastrin molecular species in serum samples from 21 patients with Zollinger-Ellison syndrome with localized gastrinoma (n = 11) or gastrinoma with hepatic metastases (n = 10). Gastrin molecular species were separated by gel-filtration chromatography and quantitated by radioimmunoassay with a gastrin antiserum produced in our laboratory. The percentage gastrin-17 of the total gastrin in the two groups differed significantly (nonparametric Wilcoxon rank test; p less than 0.01). Patients with the Zollinger-Ellison syndrome with apparently localized gastrinoma had a lower percentage of G- 17 (7.6%, SEM 1.6%) than did patients with gastrinoma with hepatic metastases (31.1%, SEM 6.1%). This procedure may be useful in the early classification of tumors in patients with Zollinger-Ellison syndrome.