Production rates of prostaglandin F, 6-keto-PGF1 alpha and thromboxane B2 by perifused human endometrium.

Human endometrium obtained from fresh hysterectomy specimens was perifused for 7 hr in 95% O2/5% CO2 at 37 degrees C. The phase of the menstrual cycle was determined by histological examination. The concentrations of PGF, 6-keto-PGF1 alpha and TxB2 in 20 min fractions of the perifusion medium were measured by radioimmunoassay and production rates were calculated in terms of dry weight of tissue. Biphasic patterns of production were observed; high initial values fell to about 20% at 2 hr and then increased to relatively stable values at about 4 hr which were maintained for the next 2 hr. During this latter period, production rates in endometria taken at different phases of the cycle differed markedly from each other; the production rates of PGF in secretory and early proliferative endometria were low (15.8 +/- 2.6, mean +/- SEM and 67.2 +/- 8.3 ng/min/g respectively) whereas they were high in late proliferative and premenstrual endometria (188.0 +/- 16.7 and 196.4 +/- 16.9 ng/min/g respectively). The patterns of production of 6-keto-PGF1 alpha and TxB2 were similar to those of PGF but the absolute values were much lower (less than 10%). We conclude that the observed rates of production of prostaglandins by perifused human endometrium are consistent with synthesis being stimulated either by estrogen or withdrawal of hormonal support and being inhibited by progesterone.