Ovariectomy and subchronic estradiol-17 beta administration decrease dopamine D1 and D2 receptors in rat striatum.

Ovariectomy and subchronic estradiol-17 beta cause a down-regulation of dopamine D1 and, to a lesser extent, D2 receptors in rat striatum. An intracellular mechanism mediates the DA receptor down-regulation, as various estrogens do not interact with membrane-bound DA receptors in vitro. A common denominator, e.g. enhanced DA turnover, is suggested to mediate the estradiol-induced DA receptor down-regulation. Ovarian factors other than estradiol are additionally proposed to be involved in the regulation of striatal DA receptors.