Does or can human placenta produce prostacyclin?
In order to resolve contradictory data on the capacity of the human placenta to produce prostacyclin (PGI2), we have quantified PGI2 synthase in 12 placentae obtained in the first trimester of pregnancy. Using a specific immunoradiometric assay and two monoclonal antibodies against the enzyme, we found PGI2 synthase to be present in the microsomal fraction of all placentae investigated, albeit in concentrations that were 1000-fold lower than in bovine aortal microsomes and 100-fold lower than in both pregnant and non-pregnant myometrium. Comparison of these data with previous reports on placental PGI2 production suggests that the contradictions between previous data are more apparent than real. We conclude that the human placenta possesses the potential for PGI2 production, that it therefore 'can' produce PGI2, but that it remains uncertain whether the placenta actually 'does' or 'does not' produce PGI2 in vivo.
D011464:Epoprostenol / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008861:Microsomes / Q000201:enzymology; D010920:Placenta / Q000201:enzymology / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis
D011464:Epoprostenol; D011451:Prostaglandin-Endoperoxide Synthases