The relationship of the serum gastrin and calcium concentrations in patients with multiple endocrine neoplasia type I.

The relationship between the serum gastrin and calcium concentrations has been examined in patients with multiple endocrine neoplasia type I. Variations in gastrin concentrations were induced by metiamide and secretin; calcium concentrations were altered by parathyroidectomy and by calcium infusion. Changes in the serum gastrin concentrations were not accompanied by changes in the serum calcium concentration. However, alteration of the serum calcium was accompanied by significant parallel changes in the serum gastrin. It is concluded that acute changes in the serum calcium may induce changes in the serum gastrin. Parathyroidectomy in these patients produced a fall in the serum gastrin, but the ability to produce large quantities of gastrin remains. It is postulated that the thyro-parathyroid hormones may modulate the relationship between calcium and gastrin.