Effects of ethyl alcohol on the adenosine 3', 5'-monophosphate system of the human gastric mucosa.

The effect of ethyl alcohol on the cyclic AMP system of the human gastric mucosa was studied in vitro. Corporic gastric mucosa was obtained from patients operated on for gastric or duodenal ulcers. Under the in vitro conditions used, ethanol at concentrations of 5% (v/v) or less stimulated the activity of adenylate cyclase and induced a dose-dependent rise of the gastric mucosal content of cyclic AMP. However, 10% ethanol increased the activity of adenylate cyclase but did not affect the gastric mucosal content of cyclic AMP. At the concentrations of 5 or 10%, ethanol inhibited the activity of cyclic AMP phosphodiesterase in a competitive manner. Reports in the literature indicate that oral ethanol stimulates the output of gastric acid at low but not at higher concentrations. The present results are consistent with the conception that the stimulatory effect of ethanol on the output of acid is mediated by an increase of the content of cyclic AMP in the gastric mucosa.