Placental expression of enzymes regulating prostaglandin synthesis and degradation.
OBJECTIVE
The purpose of this study was to characterize placental expression of the prostaglandin synthase enzymes cyclooxygenase (COX) -1 and -2 and prostaglandin dehydrogenase (PGDH, a degrading enzyme).


METHODS
Forty-one women between 20 and 37 weeks' gestation and 39 matched term controls with either spontaneous labor or premature rupture of membranes were enrolled in a prospective case-control study. The relative amounts of placental RNAs at delivery were determined using real-time polymerase chain reaction (PCR).


RESULTS
Placental COX-1 RNA decreased with advancing gestational age at delivery (R(2) = 0.13, P = .001), and increased by 43% when chorioamnionitis was present (P = .006). Among patients presenting at term, oxytocin use was associated with 30% lower expression of COX-1 (P = .01). COX-2 and PGDH were not associated with these variables.


CONCLUSIONS
Placental COX-1 RNA at delivery decreases with advancing gestational age and with oxytocin use at term. Thus, expression of placental COX-1 is not constitutive. Placental expression of COX-2 and PGDH do not correlate with gestational age, chorioamnionitis, or oxytocin use.
Hirsch
Emmet
E
Department of Obstetrics and Gynecology, Evanston Northwestern Healthcare, IL, USA.
Goldstein
Marci
M
Filipovich
Yana
Y
Wang
Hao
H
D016022:Case-Control Studies; D051545:Cyclooxygenase 1; D017931:DNA Primers; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D005865:Gestational Age; D006801:Humans; D006911:Hydroxyprostaglandin Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D007752:Obstetric Labor, Premature / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000032:analysis
D017931:DNA Primers; D008565:Membrane Proteins; D012313:RNA; D006911:Hydroxyprostaglandin Dehydrogenases; D051545:Cyclooxygenase 1; C496511:PTGS1 protein, human; D011451:Prostaglandin-Endoperoxide Synthases