Effects of Calcium on Serum Gastrin Levels in the Zollinger–Ellison Syndrome

Abstract

Serum gastrin levels were repeatedly measured in a patient with a total gastrectomy and hypergastrinemia associated with the Zollinger—Ellison syndrome. Fasting serum concentrations determined on consecutive days, and also at four-hour intervals during a 24-hour period, revealed persistent hypergastrinemia that varied within a relatively narrow range. Serum gastrin levels were found to relate directly to plasma calcium concentrations, falling by a factor of 20 with the development of hypocalcemia after parathyroidectomy for hypercalcemic hyperparathyroidism. Marked increases in serum gastrin concentration were induced by calcium infusion (12 and 20 mg per kilogram of body weight) but not by infusion of parathormone. The previously demonstrated effects of calcium in the control and stimulation of gastric acid secretion may be mediated by the polypeptide hormone gastrin.