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

Abstract

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.