Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins in rabbit gastric antral mucosa.

Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins (PGs) in rabbit gastric antral mucosa were examined. Fe(2+) inhibited the cyclooxygenase activity in the microsomal fraction. Zn(2+) suppressed the endoperoxide E(2) isomerase activity in the microsomal fraction and the 15-hydroxy PG dehydrogenase (PGDH) activity in the cytosolic fraction. Cu(2+) stimulated the cyclooxygenase activity, inhibited the PGDH activity and possibly induced non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha) Se(4+) possibly induced the non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha), as well as Cu(2+). These results suggest that Fe(2+), Zn(2+), Cu(2+) and Se(4+) can be modulators of the gastric antral mucosal PG levels by affecting the PG synthesizing enzymes, PG catabolizing enzyme and/or non-enzymatic reduction of PGG or PGH to PGF.