Purpose: The objective of this study was to investigate the influence of thyroid hormone on estradiol and progesterone secretion of human granulosa cells maintained in vitro.
Methods: Granulosa cells were obtained by aspiration of preovulatory follicles of woman undergoing assisted reproductive technology. Ovulation induction was performed with GnRH agonist, hMG, and hCG.
Results: Granulosa cells were maintained in vitro in a defined medium with added insulin. Twenty-four-hour estradiol and progesterone secretion into the medium were determined for granulosa cells growing in serum-free medium and in serum-free medium with added T4 in a concentration range of 10(-7) to 10(-11) M.
Conclusions: All concentrations of T4 used produced a statistically significant increase in progesterone secretion (range, 1.39 to 1.60 times the baseline amount). The increase in estradiol secretion reached statistical significance only at a T4 concentration of 10(-8) M (1.24 times the baseline amount).