Effects of Ethanol on Bicarbonate-Stimulated ATPase, ATP, and Cyclic AMP in Canine Gastric Mucosa 1

Summary Previous reports have demonstrated that ethanol inhibits acid secretion and active transport in the gastric mucosa. In the present studies, enzymes which have been implicated in gastric active transport (Mg2+ and Mg2+ HCO3 ATPases), as well as ATP and cAMP, were evaluated in response to ethanol. The activities of Mg2+ and Mg2+HCO3-stimulated ATPases were not altered at concentrations below 10% ethanol, but were significantly inhibited with 15 and 20%. Tissue slice incubations with 20% ethanol show significantly decreased ATP concentrations at 10, 20, and 30 min. Exposure of the dog gastric mucosa in vivo to 20% ethanol produced a significant decrease in ATP content but did not alter the cAMP level. These studies suggest that the ethanol-produced decrease in gastric ATP content may be involved in the inhibition of active ion transport observed with ethanol, but that cyclic AMP is probably not involved.