title: Effects of low-dose aspirin on gastric erosions, cyclooxygenase expression and mucosal prostaglandin-E2 do not depend on Helicobacter pylori infection.
abstract: BACKGROUND
  The mechanisms by which Helicobacter pylori and low-dose aspirin induce gastric damage are not completely elucidated.
  
  
  OBJECTIVE
  To evaluate the effects of low-dose aspirin on gastric damage, mucosal prostaglandin-E(2) levels and cyclooxygenase-enzyme expression in relation to the H. pylori status.
  
  
  METHODS
  Twenty healthy volunteers (H. pylori positive, n = 10; H. pylori negative, n = 10) received aspirin 100 mg/die for 1 week. At days 0, 1, 3 and 7, gastric mucosal lesions were studied by oesophagogastroduodenoscopy and histology. COX-1 and COX-2 were determined by immunohistochemistry and reverse-transcriptase polymerase chain reaction, and mucosal prostaglandin-E(2) levels by enzyme-linked immunosorbent assay. Nine H. pylori-positive subjects repeated the protocol after H. pylori eradication.
  
  
  RESULTS
  All groups developed a similar number of erosions. COX-1 and COX-2 expression, as well as mucosal prostaglandin-E(2) levels were not influenced by H. pylori status and aspirin medication. Helicobacter pylori-negative and H. pylori-eradicated subjects who developed aspirin-induced erosions had significant lower pre-treatment antral prostaglandin-E(2) levels than those without erosions (3.6 ng/microg vs. 6.3 ng/microg protein and 3.6 ng/microg vs. 6.0 ng/microg protein, respectively, P < 0.01 Mann-Whitney U-test).
  
  
  CONCLUSIONS
  In healthy subjects, low-dose aspirin for 1 week does neither affect cyclooxygenase expression nor mucosal prostaglandin-E(2) levels. Antral prostaglandin-E(2)-basal levels appear to be critical for development of aspirin-induced gastric damage in subjects without H. pylori infection.
authors.affiliation: Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Venerito
authors.forename: G
authors.initials: G
authors.lastname: Treiber
authors.forename: T
authors.initials: T
authors.lastname: Wex
authors.forename: D
authors.initials: D
authors.lastname: Kuester
authors.forename: A
authors.initials: A
authors.lastname: Roessner
authors.forename: F
authors.initials: F
authors.lastname: Di Mario
authors.forename: P
authors.initials: P
authors.lastname: Malfertheiner
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects*; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects*; D016022:Case-Control Studies; D051545:Cyclooxygenase 1 / Q000032:analysis / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000032:analysis / Q000378:metabolism; D015232:Dinoprostone / Q000032:analysis / Q000378:metabolism*; D004334:Drug Administration Schedule; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016481:Helicobacter Infections / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D001241:Aspirin