Oestradiol plus receptor complexes in the brain and anterior pituitary gland: Quantitation and neuroendocrine significance

Although cytosol proteins which selectively bind and translocate oestrogens to the cell nucleus have been characterized in the brain and pituitary gland, the role of these putative receptors in behavioral and neuroendocrine hormone action remains difficult to determine. Such considerations are important in view of possible non-receptor mediated mechanisms of steroid action such as iontophoreticallyapplied oestradiol modulation of neuronal activity and catechol oestrogen formation and interaction with monoamine metabolizing enzymes. This paper will review current procedures which permit the quantitation of oestradiol plus receptor complexes under physiologic conditions or following acute or chronic hormone administration. These procedures, which include [³H]oestradiol uptake and "exchange" assay of receptor bound hormone in purified nuclear pellets, have been employed to characterize patterns of oestradiol receptor occupation in several physiologic states and to study the intracellular mechanisms underlying oestrogen and androgen feedback control of pituitary gonadotropin release as well as the organizational actions of androgens on the developing neonatal rat brain.