The potentiation of taurocholate-induced rat gastric erosions following parenteral administration of cyclo-oxygenase inhibitors.

Subcutaneous administration of anti-inflammatory doses of aspirin, indomethacin, naproxen and flurbiprofen inhibited prostacyclin formation ex vivo in the luminally-perfused gastric mucosa of anaesthetized rats. These doses of anti-inflammatory compounds potentiated the formation of gastric mucosal erosions following 3 h luminal perfusion of the topical irritant, acidified sodium taurocholate (2 mM in 100 mM HCl). The increase in luminal acid-loss during gastric perfusion of acidified taurocholate was not significantly enhanced by these anti-inflammatory agents. A correlation was found between the increase in gastric erosion formation and the inhibition of mucosal prostacyclin formation ex vivo by intravenous injection of aspirin or ketoprofen during acid-taurocholate perfusion. BW755C, which failed to inhibit mucosal prostacyclin formation ex vivo, did not significantly augment acid-taurocholate induced gastric damage. The present findings support the potentiating interactions between topical irritation and inhibition of gastric cyclo-oxygenase in the genesis of the gastric lesions.