Abstract
The effects of Fe2+ and Cu2+ on prostaglandin (PG) synthesis and catabolism in rabbit gastric antral mucosal slices have been compared. Fe2+ markedly promoted the lipid peroxidation of gastric mucosal slices. The lipid peroxidation induced by Fe2+ inhibited the formation of all four PGs examined (PGE2, PGF2α, 13, 14-dihydro-15-keto PGE2 and 13, 14-dihydro-15-keto PGF2α) to a similar extent. While Cu2+ produced only a small increase in lipid peroxidation, it had a powerful stimulatory effect on PGE2 and PGF2α formation. Cu2+ induced no change in the formation of 13, 14-dihydro-15-keto PGE2 and 13, 14-dihydro-15-keto PGF2α. Moreover, tert-butyl hydroperoxide stimulated the formation of all four PGs at low concentrations (5 and 10μM), but inhibited it at a high concentration (1, 000μM). These results suggest that Cu2+ has the potential to increase the levels of biologically active PGs in gastric mucosa by affecting the activities of both PG cyclo-oxygenase and PG-catabolizing enzymes.
