Estrogen Actionin Vitro: Regulation of Thyroid Stimulating and Other Pituitary Hormones in Cell Cultures1

Primary cell cultures of ovine pituitaries can maintain production of thyroid stimulating hormone (TSH) for as long as 24 days. These cultures responded in a normal fashion to thyroxine by decreasing TSH secretion. Addition of thyrotropin releasing hormone increased TSH secretion. Physiologic levels of estradiol-17 beta (10(-11)-10(-9)M) produced a five-fold increase in secretion of TSH and a two-fold increase in intracellular TSH concentration in cell cultures. Common estrogens, but not common progestins, androgens and glucocorticoids affected TSH production. Markedly different effects of estrogen in the pituitary on follicle stimulating, luteinizing and thyroid stimulating hormones and prolactin are discussed in terms of current models of estrogen action.