Action of ethanol and some alcoholic beverages on gastric acid secretion in anaesthetized rats

The action of intragastric ethanol in various concentrations equivalent to those found in alcoholic beverages (1.5-40 v/v), ethanol 96% (v/v) and of some commonly ingested alcoholic beverages produced by alcoholic fermentation (beer, wine, champagne, martini and sherry) or by fermentation plus distillation (e.g. whisky, cognac, calvados, armagnac and rum) on gastric acid output (GAO) was studied in anaesthetized Wistar rats. Ethanol concentrations of 1.5%, 4% and 10% v/v did not significantly alter basal GAO, whereas all higher concentrations of ethanol (20%, 40% and 96% v/v) significantly (P < 0.05) and dose-dependently decreased the GAO. All alcoholic beverages produced by fermentation significantly increased GAO by 30-35% of maximal acid output (MAO; 48 micrograms/kg pentagastrin intramuscularly), whereas alcoholic beverages produced by fermentation plus distillation significantly decreased GAO as compared to control (isotonic glucose and distilled water). Glucose solutions to which yeast was added, resulting in fermentation, were as potent stimuli of GAO as beer. Lyophilized fermented glucose at different concentrations (dilution of 1:20 to 1:1) dose-dependently stimulated GAO: the highest dilution (1:20) had no effect, the 1:5 dilution significantly increased gastric acid secretion similarly to that of beer and fermented glucose. The highest concentration of lyophilized fermented glucose (1:1) was as potent as the MAO after pentagastrin (90% of MAO). In conclusion, the present investigation shows for the first time that, in rats: (1) ethanol in a concentration > 10% v/v inhibits GAO; (2) lower ethanol concentrations (< 10% v/v) do not alter GAO; (3) alcoholic beverages produced by fermentation but not those produced by alcoholic fermentation plus distillation are powerful stimulants of GAO; (4) the stimulatory non-alcoholic ingredients of these alcoholic beverages are most likely produced during the process of fermentation of carbohydrates and removed during the following process of distillation.