13, 14-DIHYDRO-15-KETO-PROSTAGLANDIN-F2-ALPHA CONCENTRATIONS IN HUMAN-PLASMA AND AMNIOTIC-FLUID

An antiserum to 13,14-dihydro-15-keto-prostaglandin F2(α) (PGF2(α)M) was prepared and a radioimmunoassay evaluated in various reproductive states. PGF2(α)M plasma concentration was 63.6 ± 10.3 pg/ml (mean ± SEM) in cycling women. The concentration fluctuated throughout the menstrual cycle and pregnancy, but no discernible patterns were noted. PGF2(α)M concentrations were evaluated at the time of urea + oxytocin induced abortion (238 ± 54 pg/ml) and during late stages of normal labor (352 ± 107 pg/ml) but were not elevated during labor prior to 7 cm dilatation. Following intra-amniotic installation of 5 mg of PGF2(α) tromethamine into the amniotic sac, PGF2(α)M concentration increased in the amniotic fluid. In the plasma of these patients there was an eighteenfold rise in plasma PGF2(α)M concentration compared to a 3.5-fold rise in PGF2(α) at 1 hour, suggesting changes in PGF2(α)M may be more easily detected than the parent compound. While PGF2(α)M may be a useful index of PGF2(α) production, it appears that PGF2(α)M is of little value in predicting the occurrence of uterine contraction.