Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Androgen shopping experience:
1. Compare - without doubt the biggest advantage that the Androgen offers shoppers today is the ability to compare thousands of Androgen at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Androgen? Wrong! If the Androgen is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Androgen then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Androgen? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Androgen and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Androgen wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Androgen then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Androgen site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Androgen, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Androgen, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
Androgen is the generic term for any natural or synthetic compound, usually a steroid
hormone, that stimulates or controls the development and maintenance of masculine characteristics in
vertebrates by binding to
androgen receptors. This includes the activity of the accessory
male sex organs and development of male secondary sex characteristics. Androgens, which were first discovered in
1936, are also called
androgenic hormones or
testoids. Androgens are also the original
anabolic steroids. They are also the precursor of all
estrogens, the female sex hormones. The primary and most well-known androgen is
testosterone.
Types of androgens
A subset of androgens,
adrenal androgens, includes any of the 19-carbon steroids synthesized by the adrenal cortex, the outer portion of the adrenal gland (zonula reticularis - innermost region of the adrenal cortex), that function as weak steroids or steroid precursors, including
dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione.
Besides testosterone, other androgens include:
- Dehydroepiandrosterone (DHEA): a steroid hormone produced in the adrenal cortex from cholesterol. It is the primary precursor of natural estrogens. Dehydroepiandrosterone is also called dehydroisoandrosterone or dehydroandrosterone.
- Androstenedione (Andro): an androgenic steroid produced by the testes, adrenal cortex, and ovaries. While androstenediones are converted metabolically to testosterone and other androgens, they are also the parent structure of estrone. Use of androstenedione as an athletic or body building supplement has been banned by the International Olympic Committee as well as other sporting organizations.
- Androstenediol: the steroid metabolite that is thought to act as the main regulator of gonadotropin secretion.
- Androsterone: a chemical by-product created during the breakdown of androgens, or derived from progesterone, that also exerts minor masculinising effects, but with one-seventh the intensity of testosterone. It is found in approximately equal amounts in the blood plasma and urine of both males and females.
- Dihydrotestosterone (DHT): a metabolism of testosterone, and a more potent androgen than testosterone in that it binds more strongly to androgen receptors. It is produced in the adrenal cortex.
Androgen functions
Development of the male
Testis formation
During mammalian development, the gonads are at first capable of becoming either
ovary or testesOnline textbook: " Developmental Biology" 6th ed. By Scott F. Gilbert (2000) published by Sinauer Associates, Inc. of Sunderland (MA).. In humans, starting at about week 4 the gonadal rudiments are present within the intermediate mesoderm adjacent to the developing kidneys. At about week 6, epithelial sex cords develop within the forming testes and incorporate the
germ cells as they migrate into the gonads. In males, certain Y chromosome genes, particularly SRY, control development of the male phenotype, including conversion of the early bipotential gonad into testes. In males, the sex cords fully invade the developing gonads.
Androgen production
The mesoderm-derived Epithelium cells of the sex cords in developing testes become the Sertoli cells which will function to support sperm cell formation. A minor population of non-epithelial cells appear between the tubules by week 8 of human fetal development. These are Leydig cells. Soon after they differentiate, Leydig cells begin to produce androgens.
Androgen effects
The androgens function as
Paracrine signalling hormones required by the Sertoli cells in order to support sperm production. They are also required for masculinization of the developing male fetus (including penis and scrotum formation). Under the influence of androgens, remnants of the
mesonephron, the Wolffian ducts, develop into the epididymis, vas deferens and
seminal vesicles. This action of androgens is supported by a hormone from Sertoli cells, Anti-müllerian hormone, which prevents the embryonic Müllerian ducts from developing into fallopian tubes and other female reproductive tract tissues in male embryos. AMH and androgens cooperate to allow for the normal movement of testes into the scrotum.
Early regulation
Before the production of the pituitary hormone Luteinizing hormone by the embryo starting at about weeks 11-12, human chorionic gonadotrophin (Human chorionic gonadotropin) promotes the differentiation of Leydig cells and their production of androgens. Androgen action in target tissues often involves conversion of testosterone to 5α-dihydrotestosterone (Dihydrotestosterone).
Spermatogenesis
During puberty, androgen, Luteinising hormone and
Follicle stimulating hormone production increase and the sex cords hollow out, forming the seminiferous tubules, and the germ cells start to differentiate into sperm. Throughout adulthood, androgens and
FSH cooperatively act on Sertoli cells in the testes to support sperm productionOnline textbook: " Endocrinology: An Integrated Approach" by S. S. Nussey and S. A. Whitehead (2001) published by BIOS Scientific Publishers, Ltd; Oxford, UK.. Exogenous androgen supplements can be used as a
male contraceptive. Elevated androgen levels caused by use of androgen supplements can inhibit production of LH and block production of endogenous androgens by Leydig cells. Without the locally high levels of androgens in testes due to androgen production by Leydig cells, the seminiferous tubules can degenerate resulting in infertility. For this reason, many transdermal androgen patches are applied to the scrotum.
Inhibition of fat deposition
Males typically have less adipose tissue than females. Recent results indicate that androgens inhibit the ability of some fat cells to store lipids by blocking a signal transduction pathway that normally supports adipocyte functionFull text article available in
PDF format: " Testosterone Inhibits Adipogenic Differentiation in 3T3-L1 Cells: Nuclear Translocation of Androgen Receptor Complex with {beta}-Catenin and TCF4 may Bypass Canonical Wnt Signaling to Downregulate Adipogenic Transcription Factors" by R. Singh, J. N. Artaza, W. E. Taylor, M. Braga, X. Yuan, N. F. Gonzalez-Cadavid and S Bhasin in
Endocrinology (2005) .
Muscle mass
Males typically have more skeletal muscle mass than females. Androgens promote the enlargement of skeletal muscle cells and probably act in a coordinated manner to enhance muscle function by acting on several cell types in skeletal muscle tissue Androgen Receptor in Human Skeletal Muscle and Cultured Muscle Satellite Cells: Up-Regulation by Androgen Treatment by Indrani Sinha-Hikim, Wayne E. Taylor, Nestor F. Gonzalez-Cadavid, Wei Zheng and Shalender Bhasin in
The Journal of Clinical Endocrinology & Metabolism (2004 ) volume 89 pages 5245-5255..
Brain
Circulating levels of androgens can influence human behavior because some neurons are sensitive to steroid hormones. Androgen levels have been implicated in the regulation of human
aggressionFull text article available in PDF format: " Testosterone and aggressiveness" by Marco Giammanco, Garden Tabacchi, Santo Giammanco, Danila Di Majo and Maurizio La Guardia in
Endocrinology (2005) and libido.
Insensitivity to androgen in humans
Reduced ability of a
sex chromosome karyotype fetus to respond to androgens can result in one of several problems, including infertility and several forms of intersex conditions. See
androgen insensitivity syndrome (AIS).
See Also
References
See also
Androgen is the generic term for any natural or synthetic compound, usually a
steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to
androgen receptors. This includes the activity of the accessory
male sex organs and development of male
secondary sex characteristics. Androgens, which were first discovered in
1936, are also called
androgenic hormones or
testoids. Androgens are also the original
anabolic steroids. They are also the precursor of all
estrogens, the
female sex hormones. The primary and most well-known androgen is
testosterone.
Types of androgens
A subset of androgens,
adrenal androgens, includes any of the 19-carbon steroids synthesized by the adrenal cortex, the outer portion of the
adrenal gland (zonula reticularis - innermost region of the adrenal cortex), that function as weak steroids or steroid precursors, including
dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione.
Besides testosterone, other androgens include:
- Androstenedione (Andro): an androgenic steroid produced by the testes, adrenal cortex, and ovaries. While androstenediones are converted metabolically to testosterone and other androgens, they are also the parent structure of estrone. Use of androstenedione as an athletic or body building supplement has been banned by the International Olympic Committee as well as other sporting organizations.
- Androstenediol: the steroid metabolite that is thought to act as the main regulator of gonadotropin secretion.
- Androsterone: a chemical by-product created during the breakdown of androgens, or derived from progesterone, that also exerts minor masculinising effects, but with one-seventh the intensity of testosterone. It is found in approximately equal amounts in the blood plasma and urine of both males and females.
Androgen functions
Development of the male
Testis formation
During mammalian development, the gonads are at first capable of becoming either
ovary or testesOnline textbook: " Developmental Biology" 6th ed. By Scott F. Gilbert (2000) published by Sinauer Associates, Inc. of Sunderland (MA).. In humans, starting at about week 4 the gonadal rudiments are present within the
intermediate mesoderm adjacent to the developing kidneys. At about week 6, epithelial
sex cords develop within the forming testes and incorporate the
germ cells as they migrate into the gonads. In males, certain
Y chromosome genes, particularly
SRY, control development of the male phenotype, including conversion of the early bipotential gonad into testes. In males, the sex cords fully invade the developing gonads.
Androgen production
The mesoderm-derived
Epithelium cells of the sex cords in developing testes become the Sertoli cells which will function to support sperm cell formation. A minor population of non-epithelial cells appear between the tubules by week 8 of human fetal development. These are Leydig cells. Soon after they differentiate, Leydig cells begin to produce androgens.
Androgen effects
The androgens function as Paracrine signalling
hormones required by the Sertoli cells in order to support sperm production. They are also required for masculinization of the developing male fetus (including penis and scrotum formation). Under the influence of androgens, remnants of the
mesonephron, the Wolffian ducts, develop into the
epididymis, vas deferens and
seminal vesicles. This action of androgens is supported by a hormone from Sertoli cells, Anti-müllerian hormone, which prevents the embryonic Müllerian ducts from developing into fallopian tubes and other female reproductive tract tissues in male embryos. AMH and androgens cooperate to allow for the normal movement of testes into the scrotum.
Early regulation
Before the production of the pituitary hormone Luteinizing hormone by the embryo starting at about weeks 11-12, human chorionic gonadotrophin (Human chorionic gonadotropin) promotes the differentiation of Leydig cells and their production of androgens. Androgen action in target tissues often involves conversion of testosterone to 5α-dihydrotestosterone (
Dihydrotestosterone).
Spermatogenesis
During puberty, androgen, Luteinising hormone and Follicle stimulating hormone production increase and the sex cords hollow out, forming the seminiferous tubules, and the germ cells start to differentiate into sperm. Throughout adulthood, androgens and
FSH cooperatively act on Sertoli cells in the testes to support sperm productionOnline textbook: " Endocrinology: An Integrated Approach" by S. S. Nussey and S. A. Whitehead (2001) published by BIOS Scientific Publishers, Ltd; Oxford, UK.. Exogenous androgen supplements can be used as a male contraceptive. Elevated androgen levels caused by use of androgen supplements can inhibit production of LH and block production of endogenous androgens by Leydig cells. Without the locally high levels of androgens in testes due to androgen production by Leydig cells, the seminiferous tubules can degenerate resulting in infertility. For this reason, many transdermal androgen patches are applied to the scrotum.
Inhibition of fat deposition
Males typically have less
adipose tissue than females. Recent results indicate that androgens inhibit the ability of some fat cells to store lipids by blocking a signal transduction pathway that normally supports adipocyte functionFull text article available in PDF format: " Testosterone Inhibits Adipogenic Differentiation in 3T3-L1 Cells: Nuclear Translocation of Androgen Receptor Complex with {beta}-Catenin and TCF4 may Bypass Canonical Wnt Signaling to Downregulate Adipogenic Transcription Factors" by R. Singh, J. N. Artaza, W. E. Taylor, M. Braga, X. Yuan, N. F. Gonzalez-Cadavid and S Bhasin in
Endocrinology (2005) .
Muscle mass
Males typically have more
skeletal muscle mass than females. Androgens promote the enlargement of skeletal muscle cells and probably act in a coordinated manner to enhance muscle function by acting on several cell types in skeletal muscle tissue Androgen Receptor in Human Skeletal Muscle and Cultured Muscle Satellite Cells: Up-Regulation by Androgen Treatment by Indrani Sinha-Hikim, Wayne E. Taylor, Nestor F. Gonzalez-Cadavid, Wei Zheng and Shalender Bhasin in
The Journal of Clinical Endocrinology & Metabolism (2004 ) volume 89 pages 5245-5255..
Brain
Circulating levels of androgens can influence human behavior because some neurons are sensitive to steroid hormones. Androgen levels have been implicated in the regulation of human aggressionFull text article available in PDF format: " Testosterone and aggressiveness" by Marco Giammanco, Garden Tabacchi, Santo Giammanco, Danila Di Majo and Maurizio La Guardia in
Endocrinology (2005) and libido.
Insensitivity to androgen in humans
Reduced ability of a
sex chromosome karyotype fetus to respond to androgens can result in one of several problems, including infertility and several forms of intersex conditions. See
androgen insensitivity syndrome (AIS).
See Also
- List of steroid abbreviations
References
See also
Definition: androgen from Online Medical Dictionary
The Online Medical Dictionary is a searchable dictionary of definitions from medicine, science and technology.
BBC - Health - Conditions - Androgen insensitivity syndrome
A guide to androgen insensitive syndrome, including how to diagnose and manage it ... Androgen insensitivity syndrome. Dr Trisha Macnair. Androgen insensitivity syndrome (AIS) is a ...
Androgen - Wikipedia, the free encyclopedia
Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine ...
Androgen insensitivity syndrome Introduction - Health encyclopaedia ...
AIS ... Androgen insensitivity syndrome (AIS) is a condition that affects the development of the internal and external genitals and reproductive organs.
Androgen insensitivity syndrome Symptoms - Health encyclopaedia - NHS ...
AIS ... As girls born with CAIS have no external physical signs, the first obvious symptoms appear during puberty.
AIS (Androgen Insensitivity Syndrome) Support Group
This site contains medical information about Androgen Insensitivity, support group contacts, newsletters and personal accounts of people with AIS
androgen - definition of androgen by the Free Online Dictionary ...
A steroid hormone, such as testosterone or androsterone, that controls the development and maintenance of masculine characteristics. Also called androgenic hormone.
Male menopause, androgen deficiency and PADAM
Both men and women undoubtedly experience symptoms related to reduced production of sex hormones (sex steroids) as they get older. These changes are inevitable, but affect ...
Androgen - definition of Androgen in the Medical dictionary - by the ...
adrenal androgens the 19-carbon steroids synthesized by the adrenal cortex that function as weak steroids or steroid precursors; e.g., dehydroepiandrosterone.
Androgen definition of Androgen in the Free Online Encyclopedia.
androgen. Any of a group of hormones that mainly influence the development of the male reproductive system. The main and most active androgen is testosterone, produced by cells in ...
