On the mechanism of the inhibitory effect of ethanol on intestinal glucose and water absorption.

Experiments were performed to investigate whether the inhibitory effect of ethanol on intestinal glucose transport is related to its action on the brush border or on the ATPase-dependent sodium pump of the basolateral membrane of the enterocyte. We compared the effect of ethanol on glucose and water transport when it was added either to the mucosal or to the serosal solution of an in vitro preparation of hamster jejunum. The purpose of the addition of ethanol to the serosal solution was to mimic a situation similar to that produced when ouabain is placed on the serosal side to inhibit the ATPase-dependent sodium pump at the basolateral membrane. The presence of 450 mM ethanol (2.07%) in the mucosal solution depressed glucose and water transport by 40 and 63%, respectively, but the presence of the same concentration of ethanol on the serosal side had no effect on glucose and water absorption. These findings seem to indicate that the depressing effect of ethanol on intestinal glucose and water transport cannot be ascribed to the inhibition of the Na+, K+-sensitive ATPase-dependent sodium pump located at the basolateral membrane.