title: Mucosal defences and gastroduodenal disease.
abstract: Peptic ulcer disease occurs when there is an imbalance between aggressive factors and mucosal resistance. Mucus plays a key role in mucosal resistance. The mucus layer is relatively resistant to peptic digestion, it provides a layer through which there is a movement of hydrogen ions from the parietal cell to the lumen but a resistance to back-diffusion of hydrogen ions in the opposite direction. It maintains a pH gradient by 'sequestering' secreted bicarbonate and by its resistance to H+ back-diffusion. Colloidal bismuth subcitrate (De-Nol) binds to mucus to stabilize the mucous layer and increase the resistance to back-diffusion of hydrogen ions without significantly modifying the ion-exchange properties of mucus.
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D004381:Duodenal Ulcer / Q000473:pathology / Q000503:physiopathology*; D005753:Gastric Mucosa / Q000473:pathology / Q000503:physiopathology*; D006168:Guinea Pigs; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000473:pathology / Q000503:physiopathology*; D007474:Ion Exchange; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D009093:Mucus / Q000502:physiology*; D009942:Organometallic Compounds / Q000627:therapeutic use; D013276:Stomach Ulcer / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; C002791:bismuth tripotassium dicitrate