Vandenbergh et al. in 1975, in which an early induction of the first estrous cycle in prepubertal female mice occurs as a result of exposure to the pheromone-laden urine of a sexually mature (dominant) male mouse.
[1][2] Physiologically, the exposure to male urine induces the release of GnRH, which provokes the first estrus.
[4] In addition to GnRH, exogenous estradiol has been implicated as having a role in the Vandenbergh effect.
The estradiol was found in a multitude of regions within the females and appeared to enter her circulation nasally and through the skin.
However, when resupplied with estradiol, the castrated males regained the ability to induce uterine growth or halt blastocyst implantation.