Using our newly developed model of esophageal perfusion in humans, we were able to study the esophagosalivary reflex in 20 healthy volunteers (12M, 8F; mean age 40 yr). The placement of the intraesophageal catheter resulted in a 6.3-fold increase in the salivation rate over the baseline value (2.27 +/- 0.28 vs. 0.36 +/- 0.06 ml/min; p = 0.02), whereas inflation of the catheter balloons evoked a 6.9-fold increase (2.52 +/- 0.21; p < 0.001) in the rate of salivation. A stepwise and significant decline of salivation (p = 0.02), observed during subsequent perfusion with NaCl was prevented when perfusion with HCl and HCl/pepsin solutions was implemented. The placement of the intraesophageal catheter resulted in a significant increase of salivary pH over its basal value (7.77 +/- 0.05 vs. 6.89 +/- 0.11; p < 0.001). A gradual decline of salivary pH during subsequent perfusion with NaCl was eliminated when saline was replaced with HCl or HCl/pepsin (7.76 +/- 0.04 vs. 7.46 +/- 0.09; p < 0.01). Intraesophageal tubing enormously potentiated the viscosity of saliva (44.50 +/- 9.0 vs. 9.3 +/- 1.0 mPa.s; p < 0.001). A subsequent decline of viscosity during continuous perfusion with saline was also prevented when HCl was substituted for NaCl (29.95 +/- 4.5 vs. 19.50 +/- 3.30; p < 0.05). A significant potentiation of salivary volume, viscosity, and pH during esophageal stimulation of mechano- and chemoreceptors may suggest a contributing role of the esophagosalivary reflex in the maintenance of the esophageal mucosal integrity under the impact gastroesophageal reflux.