Estrogen production by bovine binucleate and mononucleate trophoblastic cells in vitro

The bovine placenta has long been known as a source of steroid hormones. We performed three experiments to compare production of estrogens by bovine mononucleate and binucleate trophoblastic cells and examined effects of cortisol, progesterone, pregnenolone, testosterone, and androstenedione. In the first experiment, binucleate trophoblastic cells were purified by unit gravity sedimentation from six enzymatically dispersed placentas between 150 and 180 days of gestation. Cells (8 x 10(5)/ml) were incubated first at 37 degrees C for 6 h with Medium 199 alone (M199/6h) or with 10(-7) M cortisol (cortisol/6h). Medium then was replaced with 10(-7) M progesterone, 10(-7) M pregnenolone, 10(-7) M testosterone, or M199, and a second incubation was conducted for 4 h. Estradiol production did not differ between cells incubated for the first 6 h in M199 vs. cortisol and was not affected by progesterone or pregnenolone. Testosterone increased (p < 0.05) estradiol production. Estrone production did not differ between cells incubated for the first 6 h in M199 vs. cortisol; estrone production was not affected by either progesterone, pregnenolone, or testosterone. Mononucleate as well as binucleate cells were purified from placentas between 165 and 180 days of gestation and used in two other experiments. In the first of these, enriched populations of binucleate and mononucleate cells were incubated first for 6 h with Medium 199 (M199) or 10(-7) M cortisol. Medium then was replaced with 10(-7) M testosterone, 10(-7) M androstenedione, or M199 and incubation continued for 4 h.(ABSTRACT TRUNCATED AT 250 WORDS)