Figure 6.

Proposed model by which RFRP-3 leads to greater suppression of LH in the afternoon relative to morning injections. In the morning, RFRP-3 is proposed to have actions via GnRH cells, and potentially pituitary gonadotropes, to suppress LH. In the afternoon, based on the present findings, it is suggested that RFRP-3 acts to more potently suppress LH via additional suppression of ARC kisspeptin cells that mediate GnRH release, potentially in combination with actions on GnRH soma and/or pituitary gonadotropes. Black and thicker lines indicate points of proposed increased RFRP-3 suppression of the reproductive axis in the PM relative to AM conditions.