5-AR
links: Enzyme Steroidogenesis reference: 4-22-2021
5α-Reductase (5-AR) #
- Responsible for conversion of: (see if you can notice a pattern… there are only 2 exceptions)
- Cholestenone → 5α-Cholestanone
- Progesterone → 5α-DHP
- 3α-Dihydroprogesterone → Allopregnanolone
- 3β-Dihydroprogesterone → Isopregnanolone
- Deoxycorticosterone → 5α-Dihydrodeoxycorticosterone
- Corticosterone → 5α-Dihydrocorticosterone
- Cortisol → 5α-Dihydrocortisol
- Aldosterone → 5α-Dihydroaldosterone
- Androstanedione → 5α-Androstanedione
- Testosterone → DHT
- Nandrolone → 5α-Dihydronandrolone
- Type I: More widely expressed, namely liver, skin, scalp, prostate, and brain.
- 7 pH optima.
- Type II: not in the brain. After puberty, only II is expressed in the skin/scalp.
- 5 pH optima.
- Type III
Involved in cortisol activation
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In the brain, activity is very high in the Pituitary Gland and Hypothalamus.
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DHT is far less able to cross the blood-cerebrospinal fluid barrier than testosterone.
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Dependent on IGF-1.
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Cations Inhibit Specifically Type I Sa-Reductase Found in Human Skin
- They used SW-13 human adrenal carcinoma cells. Uh sure okay.
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(Black = type I; white = type II)