Effect of ethanol on peptic activity in the rat stomach.

Abstract

The action of ethanol on peptic activity in the stomach was evaluated by studying ethanol-induced changes in pepsinogen secretion in the rat in vivo and the effects of ethanol on pepsinogen and pepsin in vitro. Irrigation of the stomach with 3% ethanol in 100 mM HCl plus 50 mM NaCl had no effect on pepsinogen secretion, whereas 10 and 20% ethanol gave maximal increases of about 40 and 65%, respectively. 10% ethanol in 150 mM NaCl (pH 5.0) stimulated pepsinogen secretion maximally by about 60%. 10% ethanol in distilled water had no effect on spontaneous secretion of pepsinogen, but enhanced pepsinogen secretion induced by irrigation of the stomach with 100 mM HCl, 100 mM NaCl, 150 mM sucrose, or by an intravenous injection of carbachol. Ethanol inhibited the activation of pepsinogen to pepsin in vitro in a pH-dependent manner. The activity of pepsin was inhibited by ethanol with an IC50 value of about 10%. The results indicate that the effects of ethanol on pepsinogen secretion and the enzymes, pepsinogen and pepsin, are opposite in the rat. It is thus difficult to conclude what are the net effects of various concentrations of ethanol on the peptic activity of the gastric content, but at least higher concentrations can be expected to reduce this activity.