Immunocytochemical localization of estrogen receptors within neurotensin cells in the rostral preoptic area of the rat hypothalamus.

In situ hybridization procedures indicate that estrogen selectively increases neurotensin and neuromedin (NT/N) mRNA levels in the rostral preoptic area of the rat hypothalamus (RPH). Using the co-localization procedures of Axelson and Van Leeuwen, J. Neuroendocrinol., 2 (1990) 209-216, the present study examined whether NT cells in the RPH contained estrogen receptors (ER). Vibratome sections of brains from adult ovariectomized, colchicine-treated rats were first incubated with estrogen receptor antibody and stained with diaminobenzidine (DAB)-Ni+ producing a blue-black nucleus. Subsequently, NT antisera were used to provide a brown reaction product with DAB as chromogen. Approximately 25% of the NT cells in the RPH contained ER. These data support the hypothesis that NT cells in the RPH that play a role in luteinizing hormone release from the pituitary are, in part, influenced directly by estrogen feedback via nuclear ER and may act as interneurons controlling luteinizing hormone releasing hormone turnover.