Augmentation by thyroxine of human granulosa cell gonadotrophin-induced steroidogenesis

Abstract

The objective of this study was to investigate the influence of thyroid hormone on gonadotrophin-induced oestradiol and progesterone secretion by human granulosa cells maintained in vitro. Granulosa cells were obtained by aspiration of pre-ovulatory follicles from women undergoing assisted reproductive technology. Ovulation induction was performed with gonadotrophin-releasing hormone agonist, human menopausal gonadotrophin and human chorionic gonadotrophin. Granulosa cells were maintained in vitro in a defined medium with added insulin. Between 48 and 72 h after the initiation of cell culture, oestradiol and progesterone secretion into the medium was determined for granulosa cells growing in serum-free medium with follicle-stimulating hormone (FSH)/luteinizing hormone (LH) and in serum-free medium with FSH/LH and thyroxine added in a concentration range of 10⁻¹⁰–10⁻⁷ M. All concentrations of thyroxine used produced a statistically significant increase in oestradiol (range 1.18−1.37 times the amount with FSH/LH alone) and progesterone (range 1.29−1.51 times the amount with FSH/LH alone) secretion.

human granulosa cells, oestradiol secretion, progesterone secretion, thyroid hormone