Leydig cell

(noun)

one of the interstitial cells, located next to the seminiferous tubules inside the testicle, that produce testosterone

Related Terms

  • testosterone
  • luteinizing hormone
  • follicle stimulating hormone
  • inhibin
  • Sertoli cell
  • puberty

Examples of Leydig cell in the following topics:

  • Hormonal Regulation of the Male Reproductive System

    • However, it is known that initiation of spermatogenesis occurs at puberty due to the interaction of the hypothalamus, pituitary gland, and Leydig cells.
    • 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.
    • Inhibin is secreted by the Sertoli cells and acts to decrease the levels of FSH.
  • Testicular Cancer

    • Although testicular cancer can be derived from any cell type found in the testicles, more than 95% of testicular cancers are germ cell tumors .
    • Most of the remaining 5% are sex cord-gonadal stromal tumors derived from Leydig cells or Sertoli cells.
    • Most testicular germ cell tumors have too many chromosomes, and most often they are triploid to tetraploid.
    • About half of germ cell tumors of the testis are seminomas.
  • Testes

    • The tubules are lined with a layer of cells (germ cells) that develop into sperm cells (also known as spermatozoa or male gametes) from puberty into old age.
    • The developing sperm travels through the seminiferous tubules to the rete testis located in the mediastinum testis, to the efferent ducts, and then to the epididymis where newly-created sperm cells mature.
    • Leydig cells, localized 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.
    • The sertoli cells are the testis’ somatic cells necessary for testis development and spermatogenesis.
  • Male Hormones

    • FSH enters the testes, stimulating the Sertoli cells, which help to nourish the sperm cells that the testes produce, to begin facilitating spermatogenesis.
    • LH also enters the testes, stimulating the interstitial cells, called Leydig cells, to make and release testosterone into the testes and the blood.
    • The Sertoli cells produce the hormone inhibin, which is released into the blood when the sperm count is too high.
    • If the sperm count reaches 20 million/ml, the Sertoli cells cease the release of inhibin, allowing the sperm count to increase.
  • Male and Female Gonads

    • Progesterone and estrogen are secreted by granulosal cells, whereas testosterone is produced by thecal cells.
    • Prior to ovulation follicle-stimulating hormone is secreted by the granulosal cells which converts testosterone into estradiol.
    • Testosterone is secreted by Leydig cells which are located between the seminiferous tubules.
  • Hormonal Regulation of the Reproductive System

    • LH stimulates production of the sex hormones (androgens) by the Leydig cells of the testes.
    • It is also called interstitial-cell-stimulating hormone.
    • In females, FSH stimulates development of egg cells (or ova) in structures called follicles.
    • Follicle cells produce the hormone inhibin, which inhibits FSH production in the female reproductive system.
    • Oxytocin also stimulates the contraction of myoepithelial cells around the milk-producing mammary glands.
  • Aging and the Endocrine System

    • This decrease in responsiveness can be attributed to a decrease in IGF-I signaling pathways with advanced cell age.
    • Testosterone is a steroid hormone secreted by the Leydig cells.
    • 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.
    • Estrogen acts on the nucleus of the cell by binding with the nuclear endoplasmic reticulum (ER).
  • Puberty

    • LH stimulates the Leydig cells of the testes to make testosterone and blood levels begin to rise.
    • For females, as the amplitude of LH pulses increases, the theca cells of the ovaries begin to produce testosterone and smaller amounts of progesterone.
    • Much of the testosterone moves into nearby cells called granulosa cells.
    • Smaller increases of FSH induce an increase in the aromatase activity of these granulosa cells, which converts most of the testosterone to estradiol for secretion into the circulation.
  • Male Reproductive Anatomy

    • The walls of the seminiferous tubules are composed of the developing sperm cells, with the least-developed sperm at the periphery of the tubule and the fully-developed sperm in the lumen.
    • The sperm cells are mixed with "nursemaid" cells called Sertoli cells which protect the germ cells and promote their development.
    • Other cells mixed in the wall of the tubules are the interstitial cells of Leydig; these cells produce high levels of testosterone once the male reaches adolescence.
    • Sperm consist of a flagellum (as a tail), a neck that contains the cell's energy-producing mitochondria, and a head that contains the genetic material .
    • When the sperm have developed flagella, or lash-like appendages that protrude from the cell body, and are nearly mature, they leave the testicles and enter the epididymis.
  • Cellular Differentiation

    • Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells.
    • Pluripotent stem cells undergo further specialization into multipotent progenitor cells that then give rise to functional cells.
    • Hematopoietic stem cells (adult stem cells) from the bone marrow that give rise to red blood cells, white blood cells, and platelets
    • Mesenchymal stem cells (adult stem cells) from the bone marrow that give rise to stromal cells, fat cells, and types of bone cells;
    • Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells
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