Female Sprague-Dawley rats (220-240 g) were ovariectomized
and seven days later were either treated as controls or received a
single injection of either 0.1 μg, 100 μg, or 2 mg of estradiol-17β dissolved in 0.1 cc propylene glycol. These rats were autopsied
either 1, 3, 6, 24, 48, or 72...
In the first experiment, estradiol production was measured in cultured embryos collected on Days 7, 9, 11, 13 and 15 post-mating. Estradiol was detected in Day 7 embryos and production increased approximately 50-fold (P<0.05) in medium recovered from Day 13 compared to Day 11 embryos and was greatest (P<0.05) from...
Ovulation requires preovulatory surges of gonadotropin-releasing hormone (GnRH) from preoptic hypothalamic neurons, initiated by elevated ovarian estradiol (E₂). Rising estradiol activates a subset of sexually dimorphic kisspeptin (Kiss-1) neurons in the female, located in the anteroventral periventricular nuclei (AVPV). Conversely, estradiol negative feedback on GnRH secretion is mediated by a...