Effect of the association of caffeine-indomethacin on the production of prostacyclin in the rat stomach

Prostaglandin (PG) E1, PGD2 and the unstable PGI2 are inhibitors of human platelet aggregation and increase the concentration on cAMP in human platelets, presumably by stimulation of the adenylate cyclase. Methylxanthines exert their antiaggregatory effect by inhibiting the platelet cAMP phosphodiesterase. We examined whether caffeine-indomethacin is able to block PGI2 release from gastric mucosa less than the administration of indomethacin alone. PGI2 production was determined on aliquots of incubated mucosal strips, tested for ADP-induced aggregation of human platelet rich plasma. The obtained data indicate that the PGI2 production found in rats treated with the association was higher than that observed in rats treated with indomethacin alone. The present preliminary findings suggest that caffeine when given together with indomethacin reduces the indomethacin-induced inhibition of PGI2 release from the gastric mucosa.