To re-address the original question about phero breakdown in the skin…
There’s a really good review article that summarizes things nicely;
Cutaneous Androgen Metabolism: Basic Research and Clinical Perspectives
Journal of Investigative Dermatology (2002) 119, 992–1007
"**The skin, especially the pilosebaceous unit composed of sebaceous glands and hair follicles, can synthesize androgens de novo from cholesterol or by locally converting circulating weaker androgens to more potent ones. As in other classical steroidogenic organs, the same six major enzyme systems are involved in cutaneous androgen metabolism, namely steroid sulfatase, 3 -hydroxy-steroid dehydrogenase, 17 -hydroxysteroid dehydrogenase, steroid 5 -reductase, 3 -hydroxysteroid dehydrogenase, and aromatase. **
**Sex hormones, like other steroid hormones, are synthesized from their major parental precursor cholesterol, which undergoes side chain cleavage by the mitochondrial P450 side chain cleavage enzyme (P450scc) to form 5-pregnenolone, releasing a C6 aldehyde.
5-pregnenolone, the required intermediate compound in the synthesis of all steroid hormones, can be converted intracellularly to progesterone by the action of 3 -ol-dehydrogenase to 4,5-isomerase or to 17 -hydroxypregnenolone by 17 -hydroxylase.
The ring system “sterane” of the steroid hormones, carrying a cyclopentanoperhydrophenanthrene nucleus, is a stable structure that cannot be broken down by mammalian cells. Conversion of active hormones to less active or inactive forms involves alteration of ring substituents rather than the ring structure itself.
Sex hormones can be easily distinguished by the carbon numbers, C-19 being androgens, C-18 being estrogens, and C-21 being progestenoids. Androgens are derivatives of androstane and contain either a keto group [e.g., dehydroepiandrosterone (DHEA) and androstenedione] or hydroxy group [testosterone and 5 -dihydrotestosterone (5 -DHT)] at position 17 of the ring system.
In classical “central” steroidogenic organs such as the gonads and the adrenal gland, testosterone can be derived mainly from two pathways: (i) progesterone, 17 -hydroxyprogesterone, 4-androstenedione, or (ii) 17 -hydroxypregnenolone, DHEA, 5-androstenediol. Alternatively, in many “peripheral” organs, such as the skin, the potent tissue androgen testosterone results from the conversion of circulating dehydroepiandrosterone sulfate (DHEA-S), a weak but most abundant androgen in higher primates, through the serial action of steroid sulfatase, 3 -hydro-xysteroid dehydrogenase/ 5-4 isomerase (3 - 5-HSD), and 17 -HSD. Testosterone can be further “activated” to the physiologically most potent tissue androgen 5 -DHT through the action of 5 -reductase or “inactivated” to estradiol by aromatase."
http://www.nature.com/jid/journal/v119/n5/images/5601659f1.gif
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