Salivary Secretion in Reflux Esophagitis

Abstract

It has been speculated that impaired salivary flow and contents contribute to abnormal acid clearance in patients with reflux esophagitis. To test this hypothesis, salivary secretion of volume, bicarbonate, and N-acetylneuraminic acid was measured in patients with reflux esophagitis, in age- and sex-matched controls, and in healthy young volunteers. Resting saliva was collected by permitting the saliva to drip into a flask every 30 s. Parotid saliva was collected by means of a Lashley capsule during stimulation by oral infusion of 1 ml/min of 2% citric acid. Total mixed saliva was collected by a dental sucker during esophageal perfusion with water and 10-mM hydrochloric acid. The volume of resting saliva and its concentration of bicarbonate were similar in the three groups. The concentration and the output of N-acetylneuraminic acid were higher in the young volunteers than in the two other groups. The volume flow and the composition of stimulated parotid saliva were similar in the three groups of subjects. Volume of total mixed saliva and concentration of bicarbonate and N-acetylneuraminic acid during esophageal perfusion with water were higher in patients with reflux esophagitis than in age- and sex-matched controls and were similar to the values found in young healthy volunteers. Acid perfusion increased the secreted volume of total mixed saliva by 150% and the concentration of bicarbonate by 30% in healthy young volunteers, but not in patients with reflux esophagitis and in the healthy age- and sex-matched controls; the concentration of N-acetylneuraminic acid was left unaffected by acid perfusion in all three groups. These findings disprove the hypothesis of impaired salivation in reflux esophagitis. The age-related loss of salivary response to acidic esophageal perfusion might be the reason why reflux esophagitis with peptic lesions affects predominantly elder people.