Estradiol Masculinizes Hypothalamus?

Mike Kirby mkirby at
Sat Mar 16 16:15:13 EST 1996

trpede at (Pentti Degerstr|m) wrote:

> Alpha-fetoprotein binds estrogen so only testosterone enters the
> cell (during critical period in pregnancy) and is aromatized to estradiol
> after entering. Could defects in this mechanism be the cause for 
> homosexual behavior?

This is a very interesting proposal.  There is some support for a
"critical window" in fetal development where hypothalamic neurons (and
probably others) are more sensitive to hormonal factors than at other
times.  I'm refering specifically to Roger Gorsky's work in California
with his rat gender reversal experiments.  Also, pregnant women taking the
drug diethyl stilbesterol (DES) during a particular time of their
pregnancy are reported to have a higher probability of male children who
exhibit feminine behaviors.  In regards to the alpha-fetoprotein idea (I
know nothing about this yet, but I intend to do a literature search) would
be tenable in that during the "window", alpha-fetoprotein would be
restricting estrogen transport to the fetus, yet DES would circumvent this
mechanism either by saturation + excess DES or prehaps the
alpha-fetoprotein has a lower binding affinity for DES.  Either way, DES
administration during this critical window of development would have
estrogenic effects.  What are your thoughts on this?

Mike Kirby

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