5α-DHP is metabolized by the
aldo-keto reductases (AKRs)
AKR1C1,
AKR1C2, and
AKR1C4 with high catalytic efficiency.[4] AKR1C1 preferentially forms 20α-hydroxy-5α-pregnane-3-one while AKR1C2 preferentially forms allopregnanolone.[4] Similarly AKR1C1 reduces and consequently inactivates allopregnanolone into
5α-pregnane-3α,20α-diol.[4] In contrast to the other AKRs,
AKR1C3 has low catalytic efficiency for reduction of 5α-DHP.[4] These AKRs are highly expressed in the human
liver and
mammary gland but have relatively modest expression in the human
brain and
uterus.[5]
Allopregnanolone is transformed back into 5α-DHP by
3α-hydroxysteroid oxidoreductase, and conversion of allopregnanolone into 5α-DHP is responsible for the progestogenic activity of allopregnanolone.[6][12][13] 5α-DHP, via the progesterone receptor, and allopregnanolone, via the
GABAA receptor, act together to induce
lordosis in animals.[12][13] A study found that 41% of allopregnanolone that was administered via injection was transformed into 5α-DHP in the rat brain.[12]
^
abGuidotti A, Dong E, Matsumoto K, Pinna G, Rasmusson AM, Costa E (November 2001). "The socially-isolated mouse: a model to study the putative role of allopregnanolone and 5alpha-dihydroprogesterone in psychiatric disorders". Brain Res. Brain Res. Rev. 37 (1–3): 110–5.
doi:
10.1016/s0165-0173(01)00129-1.
PMID11744079.
S2CID22202599.
^Illingworth DV, Elsner C, De Groot K, Flickinger GL, Mikhail G (February 1977). "A specific progesterone receptor of myometrial cytosol from the rhesus monkey". J. Steroid Biochem. 8 (2): 157–60.
doi:
10.1016/0022-4731(77)90040-1.
PMID405534.
^
abcBeyer C, González-Flores O, Ramírez-Orduña JM, González-Mariscal G (February 1999). "Indomethacin inhibits lordosis induced by ring A-reduced progestins: possible role of 3alpha-oxoreduction in progestin-facilitated lordosis". Horm Behav. 35 (1): 1–8.
doi:
10.1006/hbeh.1998.1457.
PMID10049597.
S2CID11520064.
^
abBeyer C, Gonzalez-Flores O, Gonzalez-Mariscal G (November 1995). "Ring A reduced progestins potently stimulate estrous behavior in rats: paradoxical effect through the progesterone receptor". Physiol. Behav. 58 (5): 985–93.
doi:
10.1016/0031-9384(95)00141-5.
PMID8577898.
S2CID25967801.
5α-DHP is metabolized by the
aldo-keto reductases (AKRs)
AKR1C1,
AKR1C2, and
AKR1C4 with high catalytic efficiency.[4] AKR1C1 preferentially forms 20α-hydroxy-5α-pregnane-3-one while AKR1C2 preferentially forms allopregnanolone.[4] Similarly AKR1C1 reduces and consequently inactivates allopregnanolone into
5α-pregnane-3α,20α-diol.[4] In contrast to the other AKRs,
AKR1C3 has low catalytic efficiency for reduction of 5α-DHP.[4] These AKRs are highly expressed in the human
liver and
mammary gland but have relatively modest expression in the human
brain and
uterus.[5]
Allopregnanolone is transformed back into 5α-DHP by
3α-hydroxysteroid oxidoreductase, and conversion of allopregnanolone into 5α-DHP is responsible for the progestogenic activity of allopregnanolone.[6][12][13] 5α-DHP, via the progesterone receptor, and allopregnanolone, via the
GABAA receptor, act together to induce
lordosis in animals.[12][13] A study found that 41% of allopregnanolone that was administered via injection was transformed into 5α-DHP in the rat brain.[12]
^
abGuidotti A, Dong E, Matsumoto K, Pinna G, Rasmusson AM, Costa E (November 2001). "The socially-isolated mouse: a model to study the putative role of allopregnanolone and 5alpha-dihydroprogesterone in psychiatric disorders". Brain Res. Brain Res. Rev. 37 (1–3): 110–5.
doi:
10.1016/s0165-0173(01)00129-1.
PMID11744079.
S2CID22202599.
^Illingworth DV, Elsner C, De Groot K, Flickinger GL, Mikhail G (February 1977). "A specific progesterone receptor of myometrial cytosol from the rhesus monkey". J. Steroid Biochem. 8 (2): 157–60.
doi:
10.1016/0022-4731(77)90040-1.
PMID405534.
^
abcBeyer C, González-Flores O, Ramírez-Orduña JM, González-Mariscal G (February 1999). "Indomethacin inhibits lordosis induced by ring A-reduced progestins: possible role of 3alpha-oxoreduction in progestin-facilitated lordosis". Horm Behav. 35 (1): 1–8.
doi:
10.1006/hbeh.1998.1457.
PMID10049597.
S2CID11520064.
^
abBeyer C, Gonzalez-Flores O, Gonzalez-Mariscal G (November 1995). "Ring A reduced progestins potently stimulate estrous behavior in rats: paradoxical effect through the progesterone receptor". Physiol. Behav. 58 (5): 985–93.
doi:
10.1016/0031-9384(95)00141-5.
PMID8577898.
S2CID25967801.