title: Exposure to non-steroid anti-inflammatory drugs (NSAIDs) and suppressing hydrogen sulfide synthesis leads to altered structure and impaired function of the oesophagus and oesophagogastric junction.
abstract: BACKGROUND
  The non-steroid anti-inflammatory drugs (NSAIDs) are among the drugs that can commonly cause injury in the esophagus, such as non-reflux oesophagitis, with important clinical consequences. This injury may be 'silent' and therefore often overlooked. Recently, we established that hydrogen sulfide (H2S) is a critical mediator of esophageal mucosal protection and repair. The aim of the study was to determine the effect of naproxen, the most commonly used NSAIDs, on the oesophagus and oesophagogastric junction and its relation with suppression or stimulation of endogenous H2S synthesis during naproxen-induced oesophageal injury.
  
  
  METHODS
  Rats were treated with vehicle (control) or naproxen, with or without being subjected to water immersion restricted stress (Takagi et al. Chem Pharm Bul 12:465-472, 1964). Subgroups of rats were pre-treated with an inhibitor of H2S synthesis cystathionine γ-lyase (CSE) or cystathionine β-synthase (CBS), or with the Sodium sulphide (NaHS), which spontaneously generates H2S in solution. Damage of the oesophageal mucosa and oesophagogastric junction was estimated and scored using a histological damage index.
  
  
  RESULTS
  Treatment with naproxen increased the thickness of the corneal and epithelial layers of the oesophagus, as well as producing disorganization of the muscle plate and irregular submucosal oedema. Both injury factors, stress and suppression of H2S synthesis resulted in the development of severe esophagitis and damage to the oesophagogastric junction. The damage was exacerbated by inhibitors of H2S biosynthesis, and attenuated by treatment with NaHS.
  
  
  CONCLUSIONS
  Inhibition of endogenous H2S synthesis provides a novel experimental model that can be useful in preclinical studies NSAID-related non-reflux oesophagitis. H2S contributes significantly to mucosal defence in the oesophagus.
authors.affiliation: Department of Physiology, Lviv National Medical University, 69 Pekarska str., 79010, Lviv, Ukraine, ozayachkivska@gmail.com.
authors.forename: Oksana
authors.initials: O
authors.lastname: Zayachkivska
authors.forename: Nazar
authors.initials: N
authors.lastname: Bula
authors.forename: Dzvinka
authors.initials: D
authors.lastname: Khyrivska
authors.forename: Elena
authors.initials: E
authors.lastname: Gavrilyuk
authors.forename: John L
authors.initials: JL
authors.lastname: Wallace
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000378:metabolism; D004195:Disease Models, Animal; D004943:Esophagogastric Junction / Q000187:drug effects* / Q000293:injuries* / Q000378:metabolism / Q000502:physiology; D006862:Hydrogen Sulfide / Q000378:metabolism*; D009288:Naproxen / Q000009:adverse effects; D051381:Rats; D013440:Sulfides / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D013440:Sulfides; D009288:Naproxen; D003541:Cystathionine beta-Synthase; D003542:Cystathionine gamma-Lyase; C033479:sodium sulfide; D006862:Hydrogen Sulfide