PLACING PROGESTERONE IN THE APOPTOTIC PATHWAY

Progesterone regulates the viability of cells of several different rep roductive tissues, including the uterus, breast, corpus luteum, and ov arian follicle (that is, granulosa cells). Progesterone's antiapoptoti c actions are thought to be mediated through the progesterone receptor because the progesterone antagonist RU 486 attenuates progesterone's action. Uterine, mammary, and luteal cells express the classic nuclear progesterone receptor; whereas granulosa cells of developing and matu re follicles do not. This review presents data that suggest that proge sterone maintains granulosa cell viability through a nongenomic mechan ism. (C) 1997, Elsevier Science Inc.