Well, the first one won't do much for pure physiology. The second seems very interesting, but in proper scientific method, gives the results but doesn't give much of a how or why.
I know a transgender M>F and she's been growing breasts thanks to medication. I asked, and apparently simply getting more of that medication wouldn't cause the breasts to grow further. (If it did, augmentation surgery would quickly become obsolete, which was my reason for asking.)
My personal method that I started with for learning to play females was purely nurture. I imagined what life would be like if the various aspects were different (bullying being much more verbal and less physical, and a number of more stereotypical expectations which our culture is slowly growing out of, for example) how my perspectives would change as a result. Of course, it's a drop in the bucket when compared to everything else which shapes a personality.
However, back to topic before I go to bed.http://en.wikipedia.org/wiki/Sexual_arousal#Hormones_and_sexual_arousal
Several hormones affect sexual arousal, including testosterone, cortisol, and estradiol, however, the specific roles of these hormones are not clear.
I would look into testosterone, cortisol and estradiol. Also estrogen.http://women.webmd.com/normal-testosterone-and-estrogen-levels-in-women
Estrogen is an entire class of related hormones. They include estriol, estradiol, and estrone.
Okay, so maybe looking into estrogen also would be redundant...
It's worth noting that both men and women have both testosterone and estrogen.http://health.msn.com/mens-health/estrogen-not-just-for-females
I'll just pull up random sites as I find them and think they might be useful.
(The condition of enlarged breasts in males is known as gynecomastia.)
Gynecomastia would almost certainly be worth looking into.http://en.wikipedia.org/wiki/Gynecomastia
Due to excess testosterone levels from steroids, which is converted to estrogen, bodybuilders and other athletes are sometimes afflicted with gynecomastia in its purest form.
Here's a question which certainly feels relevant: why does testosterone convert into estrogen with steroids? I have a hunch that if you find that out, it might explain quite a bit.
Okay, somewhat random but I hope some of that helps and puts you in a general right track. If I'm not helping, I won't be offended if you say so ^_^