michael barry said:
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The sebaceous gland is absolutely required for the formation of the pilosebaceous unit as it is involved in the signaling processes that allow for the differentiation of the unit, but sebum production is not required for hair growth.
...........................absolutely Doctor. People with androgen insensitivity produce no measureable forehead sebum. THere are more openings for hair on the forehead per square cm than anywhere else on the body, including the scalp. Ive posted studies for Armando that confirm this. He just ignores them, and will answer your assertions with ridiculous questions like "whats the genetic difference between healthy hairs up front and donor area hairs"? etc.[/quote]
Mr. Barry,
The only proof that you need is the fact that men with complete androgen insensitivity have hair. You can prove Armando wrong by simply acknowledging that those individuals exist.
Those individuals do not respond to androgens...in any way...at the level of the androgen receptor. The receptor is so defective that androgens have no effect on hair, sexual differentiation, or even sebum production. In those individuals, it doesn't matter what type of five alpha reductase is causing what response, because the truth of the matter is that androgens are not required for hair growth, and thus, sebum produced by androgens is not required for hair growth.
I'm tired of this pointless debate and I'm sure that you are, as well.
Here is a study that demonstrates that pre-adrenarchal children and those with androgen insensitivity syndrome produce NO SEBUM, and yet, children and those with androgen insensitivity syndrome obviously have hair. In my opinion, this discussion is over with regards to sebum being necessary for hair growth. Obviously, the sebaceous unit is required for hair growth, but sebum production is not necessary whatsoever.
http://jcem.endojournals.org/cgi/conten ... t/76/2/524
Seriously, could there possibly be an older study? This discussion should have ended a long time ago.
"ABSTRACT The lack of demonstrable sebum in androgen-insensitive subjects
To evaluate the androgen control of sebum, subjects with complete
androgen insensitivity and male pseudohermaphrodites with inherited
5cu-reductase deficiency and decreased dihydrotestosterone (DHT) production had sebum production studied. A hydrophobic polymeric film applied to the forehead was used to measure sebum production through the use of air filled micropores.
Sebum scores of normal preadrenarchal children (ages 2-6), and normal age-matched adult males and females, were studied as well as males treated with the 5a-reductase inhibitor, finasteride, for benign prostatic hyperplasia who were studied at baseline and after drug therapy.
Androgen insensitive subjects had no sebum production by this
methodology, and the results were identical to preadrenarchal children.
In contrast, adult male pseudohermaphrodites with 5cY-reductase deficiency and a selective decrease in DHT production had sebum production scores identical to normal age-matched males. Males with benign prostatic hyperplasia treated with the 5cu-reductase inhibitor, finasteride, to lower DHT levels did not decrease the sebum score from baseline values....."
There...it's done.