Ethanol-induced mucosal injury in rabbit oesophagus

The pathogenesis of oesophagitis associated with ethanol ingestion was studied experimentally by perfusing isolated rabbit oesophagus in situ with 20% and 40% (v/v) ethanol. Since ingestion of ethanol increases duodenogastric and gastro-oesophageal reflux, the effects of HCl and bile salts (in combination with ethanol) were also investigated. The severity of oesophageal mucosal damage was assessed by using transmucosal potential difference, net ion fluxes of H+ and Na+, and mucosal permeability to two neutral molecules of different sizes, 3H-H2O and 14C-erythritol, as indicators of mucosal integrity. Macroscopic changes in the mucosa were also recorded. The results showed that the lower ethanol concentration (20%) is relatively harmless to the oesophageal mucosa. Furthermore, addition of 20% ethanol did not intensify the effects on the mucosa caused by HCl or bile salts alone. In contrast, the stronger ethanol solution (40%) did cause significant mucosal damage when used alone, and this damage was further potentiated by the presence of HCl.