Modulation of anterior pituitary dopamine receptors by estradiol 17-beta: dose-response relationship.

Exposure of ovariectomized rats to estradiol-17-beta for 48-96 hr resulted in a dose-dependent reduction in the number but not the Kd of D-2 dopamine receptors of the anterior pituitary. No influence of estrogen was observed on dopamine or muscarinic acetylcholine receptors of caudate or hypothalamus. The dose-response relationship observed suggested that the influence of estrogen is directly on the pituitary, not secondary to the alteration of dopaminergic systems in the hypothalamus.