The effects of Fe
2+ and Cu
2+ on prostaglandin (PG) synthesis and catabolism in rabbit gastric antral mucosal slices have been compared. Fe
2+ markedly promoted the lipid peroxidation of gastric mucosal slices. The lipid peroxidation induced by Fe
2+ inhibited the formation of all four PGs examined (PGE
2, PGF
2α, 13, 14-dihydro-15-keto PGE
2 and 13, 14-dihydro-15-keto PGF
2α) to a similar extent. While Cu
2+ produced only a small increase in lipid peroxidation, it had a powerful stimulatory effect on PGE
2 and PGF
2α formation. Cu
2+ induced no change in the formation of 13, 14-dihydro-15-keto PGE
2 and 13, 14-dihydro-15-keto PGF
2α. 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 Cu
2+ 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.
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