Less contribution of the nicotinic cholinergic and alpha2-adrenergic action of high acetaldehyde concentration on the inhibition of intestinal ethanol absorption.

In the present study, we investigated the effects of hexamethonium, a ganglionic nicotinic receptor blocking agents and yohimbine, an alpha2-adrenergic antagonist, on reduction of ethanol absorption in presence of high acetaldehyde concentration. Hexamethonium had no effect, whereas yohimbine by itself reduced ethanol absorption, but no additional effects were observed with presence of high acetaldehyde. Propionaldehyde had an inhibitory action on intestinal 1-propanol absorption. As both yohimbine and propionaldehyde are associated with vagus nerve activation, these results indirectly support the hypothesis that a cholinergic mechanism through vagus nerve activation is responsible for the inhibition of intestinal ethanol absorption by acetaldehyde.