5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of 5α-reductase encoded by the genes SRD5A1, SRD5A2, and SRD5A3.
3β-Hydroxysteroid dehydrogenase/Δ5-4 isomerase (3β-HSD) is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone (DHEA) in the adrenal gland. It is the only enzyme in the adrenal pathway of corticosteroid synthesis that is not a member of the cytochrome P450 family. It is also present in other steroid-producing tissues, including the ovary, testis and placenta. In humans, there are two 3β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes.
Allopregnanolone is a naturally occurring neurosteroid which is made in the body from the hormone progesterone. As a medication, allopregnanolone is referred to as brexanolone, sold under the brand name Zulresso, and used to treat postpartum depression. It is given by injection into a vein.
In enzymology, a hydroxymethylglutaryl-CoA reductase (NADPH) (EC 1.1.1.34) is an enzyme that catalyzes the chemical reaction
In enzymology, a 21-hydroxysteroid dehydrogenase (NADP+) (EC 1.1.1.151) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3alpha-hydroxysteroid dehydrogenase (A-specific) (EC 1.1.1.213) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3alpha-hydroxysteroid dehydrogenase (B-specific) (EC 1.1.1.50) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3alpha(or 20beta)-hydroxysteroid dehydrogenase (EC 1.1.1.53) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3β-hydroxy-5α-steroid dehydrogenase (EC 1.1.1.278) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3beta-hydroxy-5beta-steroid dehydrogenase (EC 1.1.1.277) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-keto-steroid reductase (EC 1.1.1.270) is an enzyme that catalyzes the chemical reaction
In enzymology, a cholestenone 5alpha-reductase (EC 1.3.1.22) is an enzyme that catalyzes the chemical reaction
In enzymology, a cortisone alpha-reductase (EC 1.3.1.4) is an enzyme that catalyzes the chemical reaction
In enzymology, a Delta14-sterol reductase (EC 1.3.1.70) is an enzyme that catalyzes the chemical reaction
In enzymology, a Delta24(241)-sterol reductase (EC 1.3.1.71) is an enzyme that catalyzes the chemical reaction
In enzymology, a Delta24-sterol reductase (EC 1.3.1.72) is an enzyme that catalyzes the chemical reaction
5α-Dihydroprogesterone is an endogenous progestogen and neurosteroid that is synthesized from progesterone. It is also an intermediate in the synthesis of allopregnanolone and isopregnanolone from progesterone.
5β-Reductase, or Δ4-3-oxosteroid 5β-reductase (EC 1.3.1.3, 3-oxo-Δ4-steroid 5β-reductase, androstenedione 5β-reductase, cholestenone 5β-reductase, cortisone 5β-reductase, cortisone Δ4-5β-reductase, steroid 5β-reductase, testosterone 5β-reductase, Δ4-3-ketosteroid 5β-reductase, Δ4-5β-reductase, Δ4-hydrogenase, 4,5β-dihydrocortisone:NADP+ Δ4-oxidoreductase, 3-oxo-5β-steroid:NADP+ Δ4-oxidoreductase) is an enzyme with systematic name 5β-cholestan-3-one:NADP+ 4,5-oxidoreductase. This enzyme catalyses the following chemical reaction
5α-Pregnan-17α-ol-3,20-dione, also known as 17α-hydroxy-dihydroprogesterone (17‐OH-DHP) is an endogenous steroid, a metabolite of 17α-hydroxyprogesterone.
5α-Pregnane-3α,17α-diol-20-one, also known as 17α-hydroxyallopregnanolone (17-OH-allo) is an endogenous steroid.
