17 Beta-estradiol-sensitivity of cultured myometrial cells.

The estrogen sensitivity of cells cultured from the rat myometrium was studied by growing the cells in the absence or presence of 1 nM 17 beta-estradiol. Following a time lag of approximately 10 days, exposure to estrogen resulted in increased incorporation of radiothymidine by the cells. Estrogen treatment also decreased isoproterenol-dependent and GTP-dependent adenylate cyclase activity, but had no effect on basal activity. These cultured cells have been shown previously to have some properties of uterine smooth muscle. The effects estrogen has in vitro, therefore, may reflect important properties in vivo that account for the mechanism by which the sex steroid decreases the sensitivity of the myometrium to isoproterenol.