Steroid hormone receptors in target cell membranes

Numerous reports of rapid steroid hormone effects in diverse cell types can not be explained by the generally prevailing theory that centers on the act ivity of hormone receptors located exclusively in the nucleus. Cell membran e forms of steroid hormone receptors coupled to intracellular signaling pat hways may also play an important role in hormone action. Membrane-initiated signals appear to be the primary response of the target cell to steroid ho rmones and may be prerequisite to subsequent genomic activation. Recent dra matic advances in this area have intensified efforts to delineate the natur e and biologic roles of all receptor molecules that function in steroid hor mone-signaling pathways. This work has profound implications for our unders tanding of the physiology and pathophysiology of hormone actions in respons ive cells and may lead to development of novel approaches for the treatment of many cell proliferative, metabolic, inflammatory, reproductive, cardiov ascular, and neurologic defects.