Circadian Control of the Female Reproductive Axis Through Gated Responsiveness of the RFRP-3 System to VIP Signaling.

ABSTRACT: Throughout most of the ovulatory cycle, estrogen negative feedback restrains the GnRH neuronal system. Just before ovulation, however, estrogen negative feedback is removed to permit stimulation of the preovulatory GnRH/LH surge (positive feedback) by the circadian clock in the suprachiasmatic nucleus (SCN). The mammalian ortholog of avian gonadotropin-inhibitory hormone, RFamide-related peptide 3 (RFRP-3), participates in the circadian-timed removal of estrogen negative feedback to permit the LH surge. The present study examined the specific neurochemical means by which the SCN controls RFRP-3 activity and explored whether the RFRP-3 system exhibits time-dependent responsiveness to SCN signaling to precisely time the LH surge. We found that RFRP-3 cells in female Syrian hamsters (Mesocric

SUBMITTER: Russo KA 

PROVIDER: S-EPMC4475714 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature