The effects of 16,16-dimethyl prostaglandin E2 + aspirin on the canine gastric mucosal barrier.

The canine gastric epithelium was exposed to solutions containing 20 mM aspirin and 20 mM aspirin + 30 micrograms/kg 16,16-dimethyl prostaglandin E2 (dmPGE2) for periods of three and forty minutes. No macroscopic hemorrhagic lesions were seen. Light microscopically, surface lesions were reduced from 10 percent (aspirin alone) to 2.5% (aspirin + dmPGE2). However, dmPGE2 does not appear to attenuate aspirin induced tight junction alterations. Discontinuities in the apical occluding complexes, hyperplastic tight junctions and stand number variability were documented in freeze fracture replicas of aspirin as well as aspirin + dmPGE2 treated dog stomachs. The results of these experiments would seem to suggest that 30 micrograms/kg dmPGE2 does not prevent aspirin induced damage to the tight junctions of the canine gastric epithelium or enhance their repair.