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, ...

weak

androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...

and

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

steroid hormone A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Withi ...

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 macromolecul ...

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

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 dehy ...

(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, ...

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 ...

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

ic than the related compound, Δ⁴-androstenediol, and has been found to stimulate the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

. When administered to rats, androstenediol, ''

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and p ...

'', has approximately 1.4% of the

icity of DHEA, 0.54% of the androgenicity of

, and 0.21% of the androgenicity of testosterone. Androstenediol possesses potent

ic 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 of estradiol at the ERα and ERβ, respectively. Although androstenediol has far lower affinity for the ERs compared to the major estrogen

estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...

, 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 A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

androstane Androstane is a C19 steroidal hydrocarbon with a gonane core. Androstane can exist as either of two isomers, known as 5α-androstane and 5β-androstane. File:androstane.png, 5α-Androstane File:androstane 5beta.png, 5β-Androstane Pharmacology ...

. It is closely related structurally to

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

(androst-4-en-17β-ol-3-one), as well as to

(5α-androstane-3β,17β-diol).

Derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...

s 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 d ...

(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 ...

(17α-ethynylandrostenediol) as well as the naturally occurring 19-norandrostane derivative norandostenediol (19-nor-5-androstenediol), have been synthesized and studied. Methandriol and its

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

s are

s and

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

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 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 derived from mult ...

s and

platelet Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby i ...

s. 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 trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...

s 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 ...

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 A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...

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 ...

, titlestyle = background:#ccccff , list1 = {{Androgen receptor modulators {{Estrogen receptor modulators {{Xenobiotic-sensing receptor modulators Androgens and anabolic steroids Androstanes Estrogens Pregnane X receptor agonists Selective ERβ agonists