not trivial. thats how dht is formed
As long as you finally understand and admit that sebaceous glands produce DHT, I'm satisfied.
QUOTE
Yeah, but THAT doesn't have anything to do (directly) with what you need to refute. What you need to refute is my study's finding that a DHT suppressor had no effect on acne. So your task is to find a study which found that a DHT suppressor _did_ have a beneficial effect on acne. Good luck with finding one!
try accutane
Accutane's beneficial effect on acne doesn't come about from its modest lowering effect on DHT. Instead, it works THE OTHER WAY AROUND: the lowering effect on DHT comes about because of its ability to shrink sebaceous glands. Take a look at the following studies. The important parts are in
bold:
Acta Derm Venereol. 1997 Sep;77(5):394-6.
"Isotretinoin, tetracycline and circulating hormones in acne" Palatsi R, Ruokonen A, Oikarinen A.
Department of Dermatology, University Central Hospital, Oulu, Finland.
Isotretinoin, used to treat severe acne, has been shown to induce hormonal changes, especially to reduce 5 alpha-reductase in the production of the tissue-derived dihydrotestosterone (DHT) metabolite 3 alpha-Adiol G. However, the effects of isotretinoin on other pituitary, adrenal or gonadal hormones have not been thoroughly elucidated. In the present study, isotretinoin administered at a dose of 0.5 mg/kg/day for 4 weeks caused no marked changes in the serum levels of pituitary, adrenal or gonadal hormones or 3 alpha-Adiol G in patients with severe papulopustulotic acne (n = 19). After 12 weeks of therapy, there was a decrease in the levels of the precursor androgens androstenedione, testosterone and 3 alpha-Adiol G in 6/9 patients. Acne improved after 4.5 months in all but 2 male patients, who had very low serum hormone binding globulins (SHBG) and a high free androgen index (FAI). Isotretinoin did not affect the elevated LH/FSH ratio in a patient with the polycystic ovarian syndrome (PCOS); nor did it change the high FAI or low SHBG in the male patients. For comparison, tetracycline had no effects on the serum hormonal levels of patients with mild acne (n = 19) after 7 days of treatment.
This study confirms that the effects of isotretinoin on the serum hormone levels are small and unlikely to be of relevance for the resolution of acne or the suppression of sebum excretion.--------------------------------------------
Arch Dermatol. 1988 Apr;124(4):540-3.
"Effect of isotretinoin on serum levels of precursor and peripherally derived androgens in patients with acne" Lookingbill DP, Demers LM, Tigelaar RE, Shalita AR.
Department of Medicine, College of Medicine, Pennsylvania State University, Hershey.
Sebaceous glands are stimulated by androgens and can convert them to more active forms. Isotretinoin, however, has a profound inhibitory effect on sebaceous gland size and function. This study evaluated the effect of isotretinoin on serum levels of precursor and tissue-derived androgens. Twenty-four subjects (15 men and nine women) were treated for 20 weeks with 1 mg/kg/d of isotretinoin. Serum samples were obtained at baseline, 8, 16, and 24 weeks, and assayed for precursor androgens--total testosterone (TT), free testosterone (free T), dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEA-S); and tissue androgens--dihydrotestosterone (DHT), and its metabolite, 3 alpha-androstanediol glucuronide (3 alpha-diol G). Isotretinoin had no meaningful effects on precursor androgens, except for producing an elevation of free T in women. In contrast, isotretinoin produced depressions in the serum levels of DHT and 3 alpha-diol G in women and in 3 alpha-diol G in men.
These decreases are believed to be the result, rather than the cause, of a reduction in the size of the sebaceous glands: The magnitude of the observed decreases may represent the amount of tissue-derived androgens that sebaceous glands normally contribute to the circulating pool.
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