Failure of Anterior Hypothalamic Lesions To Prevent Either Pituitary Reactions to Castration or the Inhibition of Such Reactions by Estrogen Treatment

Abstract

Three estrogenic regimens (0.1, 1.0 and 5.0 μg of estradiol benzoate/day for 30 days) were used to inhibit pituitary castration cell development. Each appeared equally effective in rats with and without that part of the hypothalamus which Flerkd reported to be essential for the inhibitory action of estrogen on gonadotrophin secretion. This demonstrates that estrogen can inhibit gonadotrophin secretion (at least gonadotrophin synthesis) in rats which lack the hypothetic “steroid receptors” said to exist in the anterior hypothalamus. The interpretation of these findings is discussed.