Aspirin can inhibit gastric mucosal cyclo-oxygenase without causing lesions in rat

Gastroenterology. 1983 Apr;84(4):756-61.


Dose-response relationships between aspirin-induced cyclo-oxygenase inhibition and gastric mucosal injury were studied in rats. Oral or parenteral aspirin, 25 mg/kg, inhibited prostaglandin generation by 87%-95% at 1, 3, and 6 h with no lesion formation. Aspirin, 100 mg/kg, inhibited prostaglandin generation by 95%-98% at 1, 3, and 6 h, but lesions were observed only when aspirin was given orally. Three-hour pretreatment with intraperitoneal aspirin, 12.5 mg/kg, did not enhance the mucosal injury caused by 10 mM acidified taurocholate, although prostaglandin generation was inhibited by 80%. Pretreatment with 25 mg/kg aspirin inhibited prostaglandin generation by 89% and was associated with significant mucosal injury by acidified taurocholate. We conclude that aspirin-induced 95% inhibition of gastric mucosal cyclo-oxygenase is not, by itself, sufficient to produce lesions and inhibition by greater than 80% is required to predispose the gastric mucosa to injury by otherwise mild irritants.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Animals
  • Aspirin / administration & dosage
  • Aspirin / pharmacology*
  • Cyclooxygenase Inhibitors*
  • Dose-Response Relationship, Drug
  • Epoprostenol / biosynthesis
  • Gastric Mucosa / drug effects*
  • Gastric Mucosa / enzymology
  • Injections, Intraperitoneal
  • Male
  • Rats
  • Rats, Inbred Strains
  • Taurocholic Acid / pharmacology


  • Cyclooxygenase Inhibitors
  • Taurocholic Acid
  • Epoprostenol
  • Aspirin