Deletion of Nuclear Progesterone Receptors From Kisspeptin Cells Does Not Impair Negative Feedback in Female Mice.

Reproductive function in mammals depends on the ability of progesterone (P4) to suppress pulsatile gonadotrophin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion in a homeostatic-negative feedback loop. Previous research identified that cells upstream from GnRH neurons expressing the nuclear progesterone receptor (PGR) are required for P4-negative feedback. However, the identity of these cells and the mechanism by which they reduce GnRH/LH pulsatile secretion is unknown.