Sensitization of esophageal mucosa by prior acid infusion: effect of decreasing intervals between infusions

Am J Gastroenterol. 1996 Sep;91(9):1745-8.


Objective: To determine the effect of decreasing time intervals between acid exposures on the sensitivity of the esophageal mucosa.

Methods: Ten healthy subjects with no history of gastroesophageal reflux disease who were symptomatic during a modified Bernstein acid infusion test were recruited for the study. Hydrochloric acid solutions of pH 3, 2, and 1 were sequentially tested. The weakest pH solution that was perceived by the patient was used for the study. The same duration of acid infusions (9 ml/min for 5 min) were made but with decreasing time intervals between each subsequent acid infusion (30-0 min). Esophageal sensation during each of the infusions, the amount of distilled water required to raise intraesophageal pH > 4, and the duration of residual heartburn after pH > 4 were recorded.

Results: Seven of the 10 subjects (70%) were Bernstein-positive to pH 3, two to pH 2, and only one to pH 1 solution. The median time to initial heartburn was significantly reduced only between the initial infusion and the first subsequent acid exposure 30 min later (165 vs 51.5 s, p < 0.009). Subsequent reductions in the time interval between infusions did not significantly reduce the perception threshold. The water required to clear the esophagus to pH > 4 and time required for the residual esophageal sensation to disappear were not significantly altered throughout the study.

Conclusions: These data suggest that some episodes of reflux may be felt sooner and perhaps more severely despite similar levels of acid burden in the esophagus when sensitization by a prior reflux episode occurs.

MeSH terms

  • Adult
  • Chemoreceptor Cells / drug effects
  • Chemoreceptor Cells / physiology*
  • Esophagus / drug effects
  • Esophagus / physiology*
  • Female
  • Gastric Acid*
  • Gastroesophageal Reflux / diagnosis
  • Gastroesophageal Reflux / physiopathology*
  • Heartburn / diagnosis
  • Heartburn / physiopathology*
  • Humans
  • Hydrogen-Ion Concentration
  • Male
  • Mucous Membrane / drug effects
  • Mucous Membrane / physiology
  • Pain Threshold / physiology*
  • Time Factors