Read what’s highlighted in the photo
Finesteride upregulate aromatase expression in hair follicles but not in human genitalia
So here’s what I am thinking.
So, I actually have that study saved along with many others, but since you pointed it out, I decided to read the study cited in regard to finasteride increasing aromatase expression.
Now, what I've deduced from that study (
https://core.ac.uk/download/pdf/82050951.pdf) is that,
in vitro, finasteride can cause an increase in aromatase expression. They also showed that 17b-estradiol and progesterone increased aromatase expression. I am willing to bet that the increase in aromatase expression from finasteride is actually an indirect result of an increase in the production of 17b-estradiol. Progesterone acts as an antagonist of estrogenic activity, so it would make sense that aromatase expression would increase in order to balance that antagonistic effect.
So, with that being said, we have to separate the effects of finasteride with regard to in vivo and in vitro studies. I fully agree that finasteride,
in vitro, will cause an increase in aromatase expression. However, it's much more complicated in the body because finasteride will be interfering with the body's steroid control loops and feedback mechanisms. So, in the body, finasteride will ultimately decrease aromatase expression due to the binding of estrogens in the hypothalamus and subsequent downregulation of steroid production and aromatase expression.
If we could localize the effects of finasteride to only the skin and hair, it would be a fountain of youth drug... it would be a miracle drug. Unfortunately, finasteride is not selective for certain tissues or specific parts of the body and it significantly affects HPTA regulation of steroid production and metabolism.
I think the most important thing that was in the study that you screenshoted was actually the hypothetical diagram which showed that androgen receptor activation caused an upregulation in aromatase expression and that binding of ERb caused a downregulation of the AR.. kind of an odd catch 22 feedback loop.
I'm certain that if there existed a 5AR inhibitor that only works in the skin and hair follicle, that would be essentially a cure. Now, for women... they have the same issue, but in kind of a different way. They have the hair thinning aspect (which is caused by lack of adequate aromatase expression and estrogen receptor activation), whereas men have two different issues going on: they have both a lack of aromatase expression and estrogen receptor activation AND they have excessive 5AR expression causing the binding of DHT to the AR, which encodes specific genes that cause the shedding of hair that testosterone DOES NOT encode (in other words, testosterone does not cause hair loss... at all).