Amniotic fluid differentially modulated the prostanoid system in corio-amniotic membrane during term and preterm labor

LEGUIZAMÓN G, WOLFSON M, FRANCHI AM AND FARINA MG.

San Diego, California

Congreso; 29th Annual Meeting of the Society of Maternal and Fetal Medicine (SMFM); 2009

Objective: we hypothesize that term and preterm amniotic fluid obtained before and during labor modulate PG synthesis and degradation in chorioamniotic membranes. Study Design: Amniotic fluid was obtained from (n=12) singleton pregnancies with intact membranes according to the following paradigms: term labor (TL) (n=3) and non labor (TNL) (n= 3), as well as preterm labor (PTL) (n=3 ) and non labor (PTNL) (n=3). Explant cultures from term non labor choriodecidual membranes were incubated with the amniotic fluids. COX-2, PGDH, and EP1 expression were determined by Western Blot and PGE2 and PGE2M (PGE metabolite) levels measured by radioimmunoanalysis and EIA respectively. Culture viability was determined by incubations with LPS. Results: Explant viability was confirmed by enhanced synthesis of PGE2 after incubation with LPS (control 50 pg/mL vs. LPS 200 pg/mL) (p< 0.05). PGE2 was increased by incubation with term (80 pg/mL vs. 125 pg/mL) and preterm (81 pg/mL vs 115 pg/mL) (p< 0.05) amniotic fluid from labor. PGEM increased significantly with PTNL amniotic fluid (control 40 pg/mL vs. 60 pg/mL) (p< 0.05). Explants cultures incubated with preterm amniotic fluids showed increase expression of COX-2 with PTL and no change with PTNL. PGDH protein levels decreased with PTL and its activity was enhanced by PTNL. EP1 expression did not change. Explants incubated with term fluids increased COX-2 expression with TL or TNL and decreased expression of PGDH with TL and TNL. Finally, EP1 levels decreased with TNL and increased with TL. Conclusions: Amniotic fluid modulates differentially the prostanoid system in fetal membranes during term and preterm labor. We speculate that increase PGDH activity with PTNL amniotic fluid could be associated with maintenance of uterine quiescence.