Association between gastric acid and mucin secretion in dyspeptic patients

Background and Aims: The maintenance of an intact gastric mucosa implies a balance between aggressive, such as acid, and protective factors such as mucin. We examined gastric aspirates to determine a possible correlation between gastric acid and mucin contents. Methods: Gastric contents were aspirated at gastroscopy in 14 patients. Acid content was evaluated by titration, and mucin content by gel filtration. In 4 other patients these measurements were also performed for 1-hour basal gastric secretion, and after pentagastrin stimulation. Western blot and dot blot for mucin protein were performed with polyclonal antibodies to the protein of MUC 5AC and MUC 6. Results: A positive correlation was demonstrated between acid and mucin content in 14 patients, r = 0.77. In 4 other patients mucin secretion, after pentagastrin injection, increased by 3-46 fold in comparison with basal secretion. A positive correlation was demonstrated between basal acid and mucin secretion, and stimulated acid and mucin secretion. In dot blot experiments, MUC 5AC had a significant higher dot blot intensity than MUC 6. Conclusions: There is a correlation between acid and mucin secretion rates. Secretagogue that causes acid secretion may also cause secretion of protective mucin.