Ethanol inhibits gastric acid secretion in rats through increased AMP-kinase activity

The effects of ethanol on gastric acid secretion remain controversial. The present study examines the effect of low-dose (2%) short term (15-20 min) ethanol exposure on gastric acid secretion via a potential interaction with AMP-activated protein kinase (AMPK). Real-time fluorescence digital imaging was used to provide functional evidence for the interaction of ethanol and AMPK in modulating secretagogue-induced acid secretion. Individual rat gastric glands were loaded with the pH-sensitive dye BCECF and the secretagogues carbachol (200 microM) or histamine (200 microM) were added to induce secretion. Rates of pH recovery were calculated as DeltapH(i)/Deltat. In one series of experiments, secretagogue-induced acid secretion was inhibited by 2% ethanol, or the AMPK activator AICAR monophosphate (AICAR) (20 mM). In a separate series, 2% ethanol was added in combination with compound C (20 microM), an AMPK inhibitor, to prevent activation of AMPK. 2% ethanol significantly suppressed stimulated acid secretion. In order to confirm modulation of AMPK activity by ethanol, the specific AMPK inhibitor compound C was used, which reversed the inhibitory effects of ethanol on stimulated acid secretion. This study demonstrates that low dose ethanol (2%) inhibits secretagogue-dependent acid secretion by activation of the AMPK pathway in rat gastric parietal cells.