[Role of cyclic AMP in gastric secretion. Mechanism of action of pentagastrin and cimetidine].

Studies were conducted to explore the effects of pentagastrin, cimetidine, cimetidine with pentagastrin and atropine with pentagastrin, on the gastric acidity and on cAMP accumulation in gastric fundic mucosa in six healthy human beings. Following gastroscopy, gastric juice was collected, and total gastric acidity was measured. Biopsies of fundic mucosa were obtained for estimation of cAMP. All these measurements were taken place before (control) and after the administration of the medicaments. Pentagastrin increased total gastric acidity and cAMP accumulation. Cimetidine decreased both respectively. Combination of cimetidine with pentagastrin and atropine with pentagastrin increased total gastric acidity and cAMP concentration of gastric mucosa. An excellent linear correlation was also found between gastric acidity and fundic mucosal cAMP. These results support the hypothesis of a regulatory role for pentagastrin and cimetidine in total gastric acidity via a cAMP dependent mechanism in gastric mucosa in human. Our findings give a strong indication in Grossman's proposal that the parietal cell has multiple receptors sites.