THE CONTROVERSIAL ROLE OF CAMP ON AMNIOTIC PROSTAGLANDIN RELEASE - EFFECT OF ADENYLATE-CYCLASE INHIBITION

The suggested role of cAMP in the regulation of amnionic prostaglandin release was investigated using two adenylate cyclase inhibitors, MDL 12330A and SQ 22536. These substances exhibited a dose-dependent inhib itory effect on both amnionic enzyme and cAMP levels, but they did not influence prostaglandin E (PGE) release. In addition forskolin and IB MX (3-isobutyl-1-methylxanthine), two drugs known to increase cAMP lev els, did not affect PGE output, while dibutyryl cyclic cAMP showed a d ose-dependent inhibitory effect. On the basis of our data, the suggest ed role of amnionic adenylate cyclase in triggering prostaglandin rele ase is not confirmed, and the pathway of phospholipase A(2) activation at the onset of labor remains to be elucidated.