Pepsin and the esophagus

Esophagitis results from excessive exposure of the esophagus to gastric jui ce through art ineffective or dysfunctional lo,ver esophageal sphincter mec hanism. A possible role of pepsin in damaging the esophageal mucosa with co nsequent esophagitis may be examined directly by testing pepsin under vario us conditions in experimental models of esophagitis. Since gastric juice co ntains both acid and pepsin, all experiments examine separately effects of perfusion of the esophagus by acid without and with pepsin in various combi nations. Acid perfusion alone at concentrations represented by pH 1.3 or ab ove does not produce esophagitis. The addition of pepsin to acid between pH 1 and 3.5 causes considerable acute esophageal damage. Outside the proteol ytic range, i.e., higher than pH 3.5, pepsin does not damage the esophagus. The damage caused by acidified pepsin may be made much worse by the furthe r addition of aspirin or other NSAIDs, presumably by further breaking down mucosal barriers.