|
Title: In rodents, why aren't female pups masculinized by their mother's estrogen? Post by: Dana77 on Oct 27, 2012 Hello there! ;D I'm looking for the answer to an endocrinology question...
So we know that testosterone masculinizes and defeminizes the rat brain, when given prenatally, and also soon after birth -- before the critical period ends. We also know that estradiol has the same masculinizing effects on the rat brain. For instance, a castrated male given E and P as an adult will display lordosis, but neonatal treatment with E will prevent the male from displaying lordosis when treated with E and P in adulthood. Conversely, the neonatally treated castrated male will display mounting behavior when presented with an estrous female, and the castrated male that was not treated with E neonatally will NOT display this mounting behavior. The question is, if estrogen has such an obvious masculinizing effect on the brain, why doesn't the mother's estrogen (or the pup's own estrogen) masculinize the female rat pups in the womb? I can't find a straightforward answer anywhere ??? Thanks! I really appreciate it! :hey: -Dana P.S. Yay - first post ;D Title: Re: In rodents, why aren't female pups masculinized by their mother's estrogen? Post by: bio_man on Oct 27, 2012 Hi there, welcome to the forum. α-Fetoprotien is found in blood of male and female neonates. This binds to free floating estradiol, preventing its entry into the brain. This protein, however, does not bind to androgens, testosterone is allowed to enter brain and be converted to estradiol.
Hope this helped. |