testosterone

Examples of testosterone in the following topics:

• Hormonal Regulation of the Male Reproductive System

  • If the pituitary gland is removed, spermatogenesis can still be initiated by follicle-stimulating hormone (FSH) and testosterone.
  • The Leydig cells are also capable of producing estradiol in addition to their main product, testosterone.
  • In the testes, LH binds to receptors on Leydig cells, which stimulates the synthesis and secretion of testosterone.
  • Testosterone is made in the interstitial cells of the testes.
  • The sequestering of testosterone in the testes is initiated by FSH, and only testosterone is required to maintain spermatogenesis.

• Male and Female Gonads

  • The ovaries also secrete testosterone, although at a much lower level than in males.
  • Progesterone and estrogen are secreted by granulosal cells, whereas testosterone is produced by thecal cells.
  • Luteinizing hormone results in testosterone release.
  • The presence of both testosterone and follicle-stimulating hormone is needed to support spermatogenesis.
  • Testosterone is secreted by Leydig cells, which are located between the seminiferous tubules.

• Puberty

  • For boys, an androgen called testosterone is the principal sex hormone.
  • While testosterone produces all boys' changes characterized as virilization, a substantial product of testosterone metabolism in males is estradiol.
  • The conversion of testosterone to estradiol depends on the amount of body fat and estradiol levels in boys are typically much lower than in girls.
  • LH stimulates the Leydig cells of the testes to make testosterone and blood levels begin to rise.
  • Much of the testosterone moves into nearby cells called granulosa cells.

• Aging and the Endocrine System

  • Menopause/andropause refers to the decrease in production and circulation of estradiol (estrogen) in females and testosterone in males.
  • Estradiol is the female equivalent of testosterone and is secreted from granulosa cells.
  • In vitro, cells treated with testosterone demonstrated a decrease in Ab release.
  • However, the effects of testosterone are not as potent as that of estrogen.
  • As a result, the effects of AD are diminished in the presence of both estrogen and testosterone.

• Adrenal Cortex

  • Zona reticularis, is the inner most cortical layer; the zona reticularis produces androgens, mainly dehydroepiandrosterone (DHEA) DHEA sulfate (DHEA-S), and androstenedione (the precursor to testosterone) in humans.
  • Testosterone : a hormone with a wide variety of effects, ranging from enhancing muscle mass and stimulation of cell growth to the development of the secondary sex characteristics.
  • Dihydrotestosterone (DHT): a metabolite of testosterone, and a more potent androgen than testosterone in that it binds more strongly to androgen receptors.
  • While androstenediones are converted metabolically to testosterone and other androgens, they are also the parent structure of estrone.

• Testes

  • Thee testes produce sperm (spermatogenesis) and androgens, primarily testosterone.
  • Luteinizing hormone results in testosterone release.
  • The presence of both testosterone and follicle-stimulating hormone (FSH) is needed to support spermatogenesis.
  • Leydig cells located between seminiferous tubules produce and secrete testosterone and other androgens important for sexual development and puberty, including secondary sexual characteristics such as facial hair and sexual behavior.
  • In addition, testosterone controls testicular volume.

• Muscular Atrophy and Hypertrophy

  • As testosterone is one of the body's major growth hormones, on average, men find hypertrophy much easier to achieve than women.
  • Taking additional testosterone, as in anabolic steroids, will increase results.
  • In addition, testosterone is also a medically regulated substance in most countries, making it illegal to possess it without a medical prescription.

• Administering Hormones

  • The main types of hormones involved are oestrogens, progesterone or progestins, and sometimes testosterone.
  • Hormone replacement therapy for transgender, gender variant, and transsexual people introduces hormones associated with the gender that the patient identifies with (notably testosterone for trans men and estrogen for trans women).

• Hair and Hormones

  • Men with androgenic alopecia typically have higher levels of 5-alpha-reductase, lower levels of total testosterone, higher levels of unbound/free testosterone, and higher levels of total free androgens including DHT. 5-alpha-reductase is responsible for converting free testosterone into DHT.
  • Sex hormone-binding globulin (SHBG), which is responsible for binding testosterone and preventing its bioavailability and conversion to DHT, is typically lower in individuals with high DHT.

• Female Sexual Response

  • For instance, sexual thoughts result in a rapid increase in testosterone in women who were not using hormonal contraception.
  • Inconsistent study results indicate that, although testosterone is involved in libido and sexuality of some women, its effects can be obscured by the coexistence of psychological factors in others.