The adenylate cyclase system and prostaglandin production in human decidua parietalis

We studied the beta-adrenergic system in the human decidua and its effect on prostaglandin E2 and F2a release from dispersed decidual cells in culture. Beta-adrenergic receptors in decidual membranes were partially characterized using (+)[125I]HYP. Specific binding was demonstrated with maximum binding capacity (Bmax) of 70 +/- 10.6 fmol/mg and an affinity (KD) of 20.85 +/- 1.86 pmol. cAMP dependent phosphoproteins in decidual cytosol were also identified. Two phosphoproteins of M(r) 42,000 and 22,000 were seen in all preparations. Three others (M(r) 39,000, 23,000 and 21,000) were identified in only some of the preparations. Phosphoproteins of similar M(r) to those seen in cytosol prepared from decidual homogenates were also identified in cytosol of cultured decidual cells. Phosphorylation of the 42,000 M(r) and 22,000 M(r) proteins was maximal (3.04 +/- 0.35-fold and 5.7 +/- 0.68-fold) with 10(-6) M cAMP. Cultured decidual cells produced prostaglandin E2 and F2a which increased in a dose-dependent manner in response to dbcAMP, forskolin or isoproterenol. The decidua contains an intact beta-adrenergic system that, when activated, is capable of phosphorylating specific proteins and modulating prostaglandin release.