Hormone production by the intact human corpus luteum in vitro

Progesterone production by human ovarian tissues in response to deglycosylated human chorionic gonadotrophin

Removal of carbohydrate residues from human chorionic gonadotrophin is known to reduce its biological activity in the ovaries of monkeys, pigs and rats although its binding properties appear unaffected. The present study demonstrates that such modified hCG derivatives also appear to have impaired biological activity in human ovaries in that they do not significantly stimulate progesterone secretion by follicular granulosa cells in culture or corpus luteum slices during superfusion. The derivatives also appear to reduce the normal stimulatory action of hCG when incubated with it.

Studies on the effect of gonadotropin-releasing hormone and its agonist on human luteal steroidogenesis in vitro

The possible direct effect of gonadotropin-releasing hormone (GnRH) and a potent GnRH agonist [( imBzl )-D- His6 -Pro9-NEt]-GnRH on basal and human chorionic gonadotropin (hCG)-stimulated progesterone, androstenedione, and estradiol production by cultured human luteal cells was examined. Luteal cells from the early or midluteal phase of the menstrual cycle responded to hCG stimulation with two to fivefold increases in steroid production in both short-term (4 hours) and long-term (up to 144 hours) culture in chemically defined medium without serum. After 48 hours in this system, levels of androstenedione and estradiol were very low, and progesterone was the predominant steroid produced. The addition of GnRH or a potent GnRH agonist to the medium had no effect on either basal or hCG-stimulated steroid secretion. When luteal cells were cultured longer (for up to 10 days) in the presence of serum, GnRH agonist caused no significant alteration of either basal or hCG-stimulated progesterone production. Collectively, these results support the conclusion that GnRH and its potent agonist do not act directly on human corpora luteal cells to modulate steroidogenesis.