androgen

Examples of androgen in the following topics:

• Adrenal Cortex

  • The adrenal cortex is devoted to the synthesis of corticosteroid and androgen hormones.
  • The most important androgens include:
  • Dihydrotestosterone (DHT): a metabolite of testosterone, and a more potent androgen than testosterone in that it binds more strongly to androgen receptors.
  • 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.

• Hair and Hormones

  • Androgenic alopecia also occurs in chimpanzee and orangutans.
  • Much research concerns the genetic basis of androgenic alopecia.
  • German researchers name the androgen receptor gene as a necessary condition for balding.
  • They conclude that a specific variant of the androgen receptor is needed for AGA to develop.
  • Since androgens and their interaction with the androgen receptor are the cause of AGA, the androgen receptor gene plays an important part in its development.

• Target Cell Specificity

  • An XY fetus will develop along a female pathway if the target cells fail to respond to androgen.
  • This androgen insensitivity occurs when the receptors on the target cells are unable to accept the hormone due to an impairment in receptor shape.
  • In some instances, alterations of receptor structure due to a genetic mutation can lead to a reduction in hormone–receptor affinity, as in the case of androgen insensitivity.

• Overview of the Adrenal Glands

  • The cortex mainly produces mineralcorticoids, glucocorticoids, and androgens, while the medulla chiefly produces adrenaline and nor-adrenaline.

• Adrenal Medulla

  • The adrenal cortex is devoted to the synthesis of corticosteroid and androgen hormones.

• Congenital Adrenal Hyperplasia

  • CAH is a genetic disorder in which girls are masculinized because the adrenal glands secrete large amounts of androgen during prenatal development.
  • The extra androgen does not affect a baby boy's physical development, but in baby girls it can enlarge the clitoris so that it resembles a penis.
  • During childhood and adolescence, girls with CAH prefer masculine activities and male playmates to a much greater extent than girls not exposed to these amounts of androgen.
  • Synthesis of cortisol shares steps with synthesis of mineralocorticoids such as aldosterone, androgens such as testosterone, and estrogens such as estradiol.
  • supplying enough glucocorticoid to reduce hyperplasia and overproduction of androgens or mineralocorticoids

• Anabolic Steroids and Muscles

  • Anabolic steroids , known technically as anabolic-androgen steroids (AAS) or colloquially as "steroids" (or even "roids"), are drugs that mimic the effects of testosterone and dihydrotestosterone in the body.
  • Anabolic steroids also have androgenic and masculinity-enhancing properties, including the development and maintenance of masculine characteristics such as the growth of the vocal cords, testicles and body hair (secondary sexual characteristics).
  • The pharmacodynamic action of anabolic steroids begins when the exogenous hormone penetrates the membrane of the target cell and binds to an androgen receptor located in the cytoplasm of that cell.
  • Different types of anabolic steroids bind to the androgen receptor with different affinities, depending on their chemical structure.
  • Some anabolic steroids such as methandrostenolone bind weakly to this receptor in vitro, but still exhibit androgenic effects in vivo.

• Puberty

  • For boys, an androgen called testosterone is the principal sex hormone.
  • The remaining testosterone, together with adrenal androgens is responsible for the typical androgenic changes of female puberty: pubic hair, other androgenic hair as outlined above, body odor, and acne.
  • Under the influence of androgens, the voice box, or larynx, grows in both sexes.

• Administering Hormones

  • Androgen replacement therapy (andropausal and ergogenic use) is a hormone treatment often prescribed to counter the effects of male Hypogonadism.
  • Additionally, androgen replacement therapy is used for men who have lost their testicular function to disease, cancer, or other causes.

• Hormonal Regulation of the Male Reproductive System

  • Follicle-stimulating hormone stimulates both the production of androgen-binding protein by Sertoli cells and the formation of the blood-testis barrier.
  • Androgen-binding protein is essential to concentrating testosterone in levels high enough to initiate and maintain spermatogenesis, which can be 20-50 times higher than the concentration found in blood.