Adrenaline sensitive adenylate cyclase in human gastric mucosa

Basal and adrenaline-stimulated adenylate cyclase (AC) was studied in biopsy specimens of the gastric and duodenal mucosa from 112 individuals. AC activities were log normally distributed. AC of fundic and antral gastric mucosa responded to adrenaline in a concentration-dependent manner, that of the duodenal mucosa did not respond to adrenaline. The degree of activation in biopsies of normal gastric mucosa was similar to that of patients with chronic atrophic gastritis or patients antrectomized according to the Billroth method. AC in biopsies from cimetidine-treated peptic ulcer patients was less sensitive to adrenaline than AC in biopsies from untreated patients. The threshold concentration of cimetidine to inhibit adrenaline-stimulated AC in vitro was 10(-6) mol/l. The data provide evidence of an adrenaline-sensitive AC in cells other than parietal cells and show an inhibitory action of cimetidine on the catecholamine-sensitive AC in the human gastric mucosa.