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Androstanes
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 includes the embryological development of the primary male sex organs, and the development of male secondary sex characteristics at puberty. Androgens are synthesized in the testes, the ovaries, and the adrenal glands. Androgens increase in both males and females during puberty. The major androgen in males is testosterone. Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development. DHT ''in utero'' causes differentiation of the penis, scrotum and prostate. In adulthood, DHT contributes to balding, prostate growth, and sebaceous gland activity. Although androgens are commonly thought of only as male sex hormones, females also have them, but at lower levels: they function in libido and sexual arousal. Also, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androstenediol
Androstenediol, or 5-androstenediol (abbreviated as A5 or Δ5-diol), also known as androst-5-ene-3β,17β-diol, is an endogenous weak androgen and estrogen steroid hormone and intermediate in the biosynthesis of testosterone from dehydroepiandrosterone (DHEA). It is closely related to androstenedione (androst-4-ene-3,17-dione). Biological activity Androstenediol is a direct metabolite of the most abundant steroid produced by the human adrenal cortex, DHEA. It is less androgenic than the related compound, Δ4-androstenediol, and has been found to stimulate the immune system. When administered to rats, androstenediol, ''in vivo'', has approximately 1.4% of the androgenicity of DHEA, 0.54% of the androgenicity of androstenedione, and 0.21% of the androgenicity of testosterone. Androstenediol possesses potent estrogenic activity, similarly to DHEA and 3β-androstanediol. It has approximately 6% and 17% of the affinity of estradiol at the ERα and ERβ, respectively. Although and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues including the prostate gland, seminal vesicles, epididymides, skin, hair follicles, liver, and brain. This enzyme mediates reduction of the C4-5 double bond of testosterone. Relative to testosterone, DHT is considerably more potent as an agonist of the androgen receptor (AR). In addition to its role as a natural hormone, DHT has been used as a medication, for instance in the treatment of low testosterone levels in men; for information on DHT as a medication, see the androstanolone article. Biological function DHT is biologically important for sexual differentiation of the male genitalia during embryogenesis, maturation of the penis and scrotum at puberty, growth of facial, body, and pubic hair, and development and maintenance of the pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydroepiandrosterone Sulfate
Dehydroepiandrosterone sulfate, abbreviated as DHEA sulfate or DHEA-S, also known as androstenolone sulfate, is an endogenous androstane steroid that is produced by the adrenal cortex. It is the 3β-sulfate ester and a metabolite of dehydroepiandrosterone (DHEA) and circulates in far greater relative concentrations than DHEA. The steroid is hormonally inert and is instead an important neurosteroid and neurotrophin. Biological activity Neurosteroid activity Similarly to other conjugated steroids, DHEA-S is devoid of hormonal activity, lacking affinity for the steroid hormone receptors. However, DHEA-S retains activity as a neurosteroid and neurotrophin. It has been found to act as a positive allosteric modulator of the NMDA receptor (50 nM–1 μM), negative allosteric modulator of the GABAA and glycine receptors, and weak agonist of the sigma-1 receptor (Kd > 50 μM). In addition, DHEA-S has been found to directly bind to and activate the TrkA and p75NT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydroepiandrosterone
Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans. DHEA is produced in the adrenal glands, the gonads, and the brain. It functions as a metabolic intermediate in the biosynthesis of the androgen and estrogen sex steroids both in the gonads and in various other tissues. However, DHEA also has a variety of potential biological effects in its own right, binding to an array of nuclear and cell surface receptors, and acting as a neurosteroid and modulator of neurotrophic factor receptors. In the United States, DHEA is sold as an over-the-counter supplement, and medication called prasterone. Biological function As an androgen DHEA and other adrenal androgens such as androstenedione, although relatively weak androgens, are responsible for the androgenic effects of adrenarche, such as early pubic and axillary hair growth, adult-type body odor, increased oiliness of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 dehydroepiandrosterone (DHEA). It is closely related to androstenediol (androst-5-ene-3β,17β-diol). Biological function Androstenedione is a precursor of testosterone and other androgens, as well as of estrogens like estrone, in the body. In addition to functioning as an endogenous prohormone, androstenedione also has weak androgenic activity in its own right. Androstenedione has been found to possess some estrogenic activity, similarly to other DHEA metabolites. However, in contrast to androstenediol, its affinity for the estrogen receptors is very low, with less than 0.01% of the affinity of estradiol for both the ERα and ERβ. Adrenarche In children aged 6 to 8 years old, there is a rise in androstenedione secretion along with DHEA during adr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 system, male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of androgenic hair, body hair. In addition, testosterone in both sexes is involved in health and well-being, including moods, behaviour, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss. Testosterone is a steroid from the androstane class containing a ketone and a hydroxyl group at positions three and seventeen respectively. It is Biosynthesis, biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites. It exerts its action through binding to and activation of the androgen receptor. In humans and most other vertebrates, testost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPRC6A
G protein-coupled receptor family C group 6 member A (GPRC6A) is a protein that in humans is encoded by the ''GPRC6A'' gene. This protein functions as a receptor of L-α-amino acids, cations (e.g., calcium), osteocalcin, and steroids. It is a membrane androgen receptor. Clinical significance GPRC6A has also been linked to prostate cancer progression, and it has been shown to mediate rapid, non-genomic prostate cancer cell responses to testosterone. See also * ZIP9 Zinc transporter ZIP9, also known as Zrt- and Irt-like protein 9 (ZIP9) and solute carrier family 39 member 9, is a protein that in humans is encoded by the ''SLC39A9'' gene. This protein is the 9th member out of 14 ZIP family proteins, which is ... References Further reading * * * * * External links * * G protein-coupled receptors {{transmembranereceptor-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Steroids
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and signaling cascades. The polypeptide hormones luteinizing hormone, follicle-stimulating hormone and gonadotropin-releasing hormone – each associated with the gonadotropin axis – are usually not regarded as sex hormones, although they play major sex-related roles. Production Natural sex hormones are made by the gonads (ovaries or testes), by adrenal glands, or by conversion from other sex steroids in other tissue such as liver or fat. Image:Steroidogenesis.svg Image:Biosinthesis of steroid hormones (simplified version).jpg Image:Biosinthesis of steroid hormones (extended version).jpg Imag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Performance Enhancement
Performance-enhancing substances, also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. A well-known example of cheating in sports involves doping in sport, where banned physical performance-enhancing drugs are used by athletes and bodybuilding, bodybuilders. Athletic performance-enhancing substances are sometimes referred to as ergogenic aids. Cognitive performance-enhancing drugs, commonly called nootropics, are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance. The use of performance-enhancing drugs spans the categories of legitimate use and substance abuse. Definition The classifications of substances as performance-enhancing substances are not entirely clear-cut and objective. As in other types of categorization, certain Prototype theory, prototype performance enhancers are universally cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bodybuilding
Bodybuilding is the use of progressive resistance exercise to control and develop one's muscles (muscle building) by muscle hypertrophy for aesthetic purposes. It is distinct from similar activities such as powerlifting because it focuses on physical appearance instead of strength. An individual who engages in this activity is referred to as a bodybuilder. In professional bodybuilding, competitors appear in lineups and perform specified poses (and later individual posing routines) for a panel of judges who rank them based on symmetry, muscularity, size, conditioning, posing, and stage presentation. Bodybuilders prepare for competitions through the elimination of nonessential body fat, enhanced at the last stage by a combination of extracellular dehydration and carbo-loading, to achieve maximum muscular definition and vascularity; they also tan and shave to accentuate the contrast of their skin under the spotlights. Bodybuilding takes a great amount of effort and time to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 also a secondary site of androgen synthesis. – "Adrenal Gland" Layers The adrenal cortex comprises three main zones, or layers that are regulated by distinct hormones as noted below. This ''anatomic zonation'' can be appreciated at the microscopic level, where each zone can be recognized and distinguished from one another based on structural and anatomic characteristics. ;Zona glomerulosa :The outermost layer, the zona glomerulosa is the main site for the production of aldosterone, a mineralocorticoid. The synthesis and secretion of aldosterone are mainly regulated by the renin–angiotensin–aldosterone system. The zona glomerulosa cells express a specific enzyme aldosterone synthase (also known as CYP11B2). Aldosterone is largel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zona Reticularis
The zona reticularis (sometimes, reticulate zone) is the innermost layer of the adrenal cortex, lying deep to the zona fasciculata and superficial to the adrenal medulla. The cells are arranged cords that project in different directions giving a net-like appearance (L. reticulum - net). Cells in the zona reticularis produce precursor androgens including dehydroepiandrosterone (DHEA) and androstenedione from cholesterol. DHEA is further converted to DHEA-sulfate via a sulfotransferase, SULT2A1. These precursors are not further converted in the adrenal cortex if the cells lack 17β-Hydroxysteroid dehydrogenase. Instead, they are released into the blood stream and taken up in the testis and ovaries to produce testosterone and the estrogens respectively. ACTH partially regulates adrenal androgen secretion, also CRH. In humans the reticularis layer does contain 17α-hydroxylase; this hydroxylates pregnenolone, which is then converted to cortisol by a mixed function oxidase. In rode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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