5β-Dihydrotestosterone (5β-DHT), also known as 5β-androstan-17β-ol-3-one or as etiocholan-17β-ol-3-one, is an
etiocholane (5β-
androstane)
steroid
A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration.
Steroids have two principal biological functions: as important components of cell membranes t ...
as well as an inactive
metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
of
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
formed by
5β-reductase in the
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
and
bone marrow
Bone marrow is a semi-solid biological tissue, tissue found within the Spongy bone, spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It i ...
and an
intermediate in the formation of
3α,5β-androstanediol and
3β,5β-androstanediol (by
3α- and
3β-hydroxysteroid dehydrogenase) and, from them, respectively,
etiocholanolone and
epietiocholanolone (by
17β-hydroxysteroid dehydrogenase).
Unlike its
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...
5α-dihydrotestosterone (5α-DHT or simply DHT), 5β-DHT either does not bind to or binds only very weakly to the
androgen receptor
The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...
.
5β-DHT is notable among metabolites of testosterone in that, due to the fusion of the A and B rings in the ''cis'' orientation, it has an extremely angular
molecular shape, and this could be related to its lack of
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...
ic activity.
5β-DHT, unlike 5α-DHT, is also inactive in terms of
neurosteroid activity,
although its metabolite, etiocholanolone, does possess such activity.
See also
*
3α-Androstanediol
*
3β-Androstanediol
*
Androsterone
*
Epiandrosterone
References
{{DEFAULTSORT:Dihydrotestosterone, 5β-
Etiocholanes
Human metabolites