Androstenediol, or 5-androstenediol (abbreviated as A5 or Δ⁵-diol), also known as androst-5-ene-3β,17β-diol, is an

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

weak androgen and estrogen steroid hormone and intermediate in the

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

of testosterone from dehydroepiandrosterone (DHEA). It is closely related to

androstenedione Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ4-dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepia ...

(androst-4-ene-3,17-dione).

Biological activity

Androstenediol is a direct

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 the most abundant

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

produced by the human

adrenal cortex The adrenal cortex is the outer region and also the largest part of an adrenal gland. It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis. Each zone is responsible for producing specific hormones. It is ...

, DHEA. It is less androgenic than the related compound, Δ⁴-androstenediol, and has been found to stimulate the immune system. When administered to

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

s, androstenediol, '' in vivo'', has approximately 1.4% of the androgenicity of DHEA, 0.54% of the androgenicity of

, and 0.21% of the androgenicity of testosterone. Androstenediol possesses potent estrogenic activity, similarly to DHEA and

3β-androstanediol 3β-Androstanediol, also known as 5α-androstane-3β,17β-diol, and sometimes shortened in the literature to 3β-diol, is an endogenous steroid hormone and a metabolite of androgens like dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT). ...

. It has approximately 6% and 17% of the

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Partn ...

of estradiol at the ERα and ERβ, respectively. Although androstenediol has far lower affinity for the ERs compared to the major estrogen estradiol, it circulates at approximately 100-fold higher concentrations, and so is thought may play a significant role as an estrogen in the body.

Chemistry

Androstenediol, also known as androst-5-ene-3β,17β-diol, is a naturally occurring androstane

. It is closely related structurally to

(A4; androst-4-ene-3,17-dione), dehydroepiandrosterone (DHEA; androst-5-en-3β-ol-17-one), and testosterone (androst-4-en-17β-ol-3-one), as well as to

(5α-androstane-3β,17β-diol). Derivatives and analogues of androstenediol, such as the 17α-substituted

methandriol Methandriol (brand names Anabol, Crestabolic, Cytobolin, Diandren, Durabolic, Madiol, Mestenediol, Methabolic, Methydiol, Sterabolic, Stenediol), also known as methylandrostenediol, is an androgen and anabolic steroid (AAS) medication which was ...

(17α-methylandrostenediol) and

ethinylandrostenediol Ethinylandrostenediol (developmental code name SKF-2856), also known as 17α-ethynyl-5-androstenediol, is a synthetic estrogen, progestogen, and androgen which was never marketed.Tan, V. Y. (2010). Characterization of the estrogenic activity of a ...

(17α-ethynylandrostenediol) as well as the naturally occurring

19-norandrostane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

derivative norandostenediol (19-nor-5-androstenediol), have been synthesized and studied. Methandriol and its esters are androgens and

anabolic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone (medication), testosterone as well as synthetic androgens that are structurally related ...

s while ethinylandrostenediol is an estrogen.

Research

Radiation countermeasure

Androstenediol has been investigated for use as a radiation countermeasure. Its value as a radiation countermeasure is based mainly on its stimulation of production of

white blood cell White blood cells, also called leukocytes or leucocytes, are the cell (biology), cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and de ...

s and platelets. Its potential use as a

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

countermeasure was developed by the

Armed Forces Radiobiology Research Institute The Armed Forces Radiobiology Research Institute (AFRRI) is an American triservice research laboratory in Bethesda, Maryland chartered by Congress in 1960 and formally established in 1961. It conducts research in the field of radiobiology and r ...

(AFRRI) and subsequently studied by AFRRI and Hollis-Eden Pharmaceuticals under the proposed brand name Neumune for the treatment of acute radiation syndrome. The clinical trials with

rhesus monkey The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally b ...

s were successful. According to the Hollis-Eden report, only 12.5% of the 40 Neumune-treated animals died versus 32.5% in the placebo group. Hollis-Eden had applied for a contract from the U.S. Government under the BioShield Request for Proposals (RFP) for radiation countermeasures. After being encouraged for 2.5 years that Neumune was in the competitive range, on March 9, 2007, the RFP was canceled by HHS. According to HHS, "the product was no longer in the competitive range".US cancels radiation contract with Hollis-Eden
, March 9, 2007 No further explanation was given. As a result, Hollis-Eden has now withdrawn from the radiation countermeasure field.

Additional images

References

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Biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

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