Calcium, histamine, and pentagastrin: speculations about the regulation of gastric acid secretion at cellular level.

The acid secretory response to acetylcholine, histamine, pentagastrin and db-cAMP was studied in dependence of serosal calcium and magnesium level in the isolated whole stomach of the mouse. Histamine- or db-cAMP-induced acid secretion from isolated stomach was not dependent on calcium. Secretory responses to pentagastrin and acetylcholine were strongly diminished in the absence of serosal calcium. Reduction of serosal magnesium concentration influenced neither histamine- nor pentagastrin-induced secretion. The calcium-antagonist verapamil reduced only acid response to pentagastrin. A working hypothesis has been discussed to understand the possible role of calcium in the regulation gastric acid secretion.