Abstract
Exposure of ovariectomized rats to estradiol‐17‐β 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.