Effect of prostaglandin E2 on aspirin-induced gastric mucosal injury.

In a series of experiments using a canine chambered stomach preparation, the effect of intravenous 16,16-dimethyl prostaglandin E₂ (dmPGE₂) on the alterations in hydrogen-ion (H⁺) permeability and potential difference (PD) induced by 5 mN aspirin (ASA) were assessed. This analogue was found to effectively prevent, in a dose-related manner, the increase in H⁺ permeability and the decrease in PD elicited by the topical application of ASA to the canine gastric mucosa. The most effective protective doses were 0.001, 0.01, and 0.1 μg/kg intravenously. Since doses of dmPGE₂ 1 and 10% of the ED₅₀ for antisecretion (0.1 μg/kg) offered comparable protection against mucosal damage to that of the antisecretory dose, it is concluded that the mechanisms of protection and antisecretion are distinct and independent of each other.