Effect of oral 16,16-dimethyl prostaglandin E2 on gastric mucosal salicylate concentration in the rat.

The effect of 16,16-dimethyl prostaglandin E2 (DmPGE2), in doses subthreshold for antisecretory activity, were examined in female rats. The aims were to determine if DmPGE2 alters the disposition of acetylsalicylic acid (ASA) within the gastric mucosa and if DmPGE2 could attenuate the ulcerogenic effect of oral ASA. Gastric lesions occurred after an oral, but not an intravenous dose of 150 mg/kg ASA. Lesions could be prevented by pretreatment with 5 micrograms/kg DmPGE2 orally 30 min prior to ASA. DmPGE2 elevated fundic concentrations of both ASA and salicylic acid (SA) within the first hour when ASA was given orally. The ratio of the concentration of ASA/SA in fundus was not changed, indicating that DmPGE2 did not depress the fundic esterase activity. It is concluded that the cytoprotective effect of DmPGE2 is not related to a change in mucosal concentration or elimination of ASA or SA.