[Oxytocin- and prostaglandin plasma concentrations before and after spontaneous labor: evidence of involvement of prostaglandins in the mechanism of placental separation].
The concentrations of oxytocin and PGE, PGF, and 13,14-dihydro-15-keto-PGF2 alpha (PGFM) in maternal peripheral plasma were measured in serial samples taken at full cervical dilatation and 5, 30 and 120 minutes postpartum. The prostanoid levels were also measured in serial samples of umbilical cord blood taken from the placental end in 4 instances. At full dilatation, plasma PGFM, but not PGE and PGF, was significantly raised over control (no labor) values. Just before or at the time of placental separation (5 minutes postpartum), the concentrations of PGF and PGFM were maximal, about twice the level at full dilatation. The level then decreased but at a slower rate than the metabolic clearance rates, indicating that considerable PGF production occurs in decidua and myometrium in the early postpartum period, after fetus, placenta, and the membranes are expelled. The rapid increase in the prostanoid concentrations in the umbilical cord blood draining the placenta after delivery of the infant suggests that the surge of prostaglandins 5 minutes postpartum originates in the placenta, and probably contributes to uterine contraction and placental separation and expulsion. Plasma OT was significantly raised over prelabor values at full cervical dilatation, and during the third stage, but dropped to control levels 30 minutes postpartum. Exogenous oxytocin infusions begun at delivery of the infant caused a marked increase in plasma OT and maintained the PGFM concentrations at a higher level than in the parturients not receiving oxytocin 2 hours postpartum.
D000328:Adult; D015237:Dinoprost / Q000031:analogs & derivatives*; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007231:Infant, Newborn; D007749:Labor Stage, Third; D007743:Labor, Obstetric; D010121:Oxytocin / Q000097:blood*; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy; D011453:Prostaglandins / Q000097:blood*; D011458:Prostaglandins E / Q000097:blood; D011460:Prostaglandins F / Q000097:blood
D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D010121:Oxytocin; D015237:Dinoprost
Oxytozin- und Prostaglandinplasmakonzentration vor und nach spontaner Geburt: Hinweis für die Beteiligung von Prostaglandinen am Mechanismus der Plazentalösung.