LOCALIZATION OF ESTROGEN RECEPTORS IN RAT HYPOTHALAMUS

An effort has been made to localize estradiol binding agents believed to exist in the hypothalamus of the male and feamle rat. The preoptic area, arcuate nucleus, and mammillary regions of rats injected with 3H-estradioi were histologically separated. Label content and retention patterns found in tissue sections containing the preoptic area and arcuate nucleus suggest the presence of receptor molecules in these loci. Retention behavior of the mammillary region suggests the presence of some binding action, but action of questionable significance. Neither the region ¡interior to the preoptic area, that posterior to the mammillary region, nor the thalamus demonstrated estradiol accumulation and retention patterns similar to those known to be characteristic of estrogen sensitive tissues. None of these neural tissues have been implicated as estrogen sensitive tissues, and one would not expect to find receptor activity in these areas. © 1969 S. Karger AG, Basel.