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Leydig cell
Testicle-histology-boar-2.jpg
Histological section through testicular parenchyma of a boar. 1 Lumen of convoluted part of the seminiferous tubules, 2 spermatids, 3 spermatocytes, 4 spermatogonia, 5 Sertoli cell, 6 myofibroblasts, 7 Leydig cells, 8 capillaries
Leydig cells.JPG
Cross-section of seminiferous tubules. Arrows indicate location of Leydig cells.
Gray's subject #258 1243
MeSH Leydig+cells

Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone (LH). Leydig cells are polyhedral in shape, display a large prominent nucleus, an eosinophilic cytoplasm and numerous lipid-filled vesicles.

Contents

Nomenclature

Leydig cells are named after the German anatomist Franz Leydig, who discovered them in 1850.[1]

Functions

Leydig cells release a class of hormones called androgens (19-carbon steroids). They secrete testosterone, androstenedione and dehydroepiandrosterone (DHEA), when stimulated by the pituitary hormone luteinizing hormone (LH). LH increases cholesterol desmolase activity (an enzyme associated with the conversion of cholesterol to pregnenolone), leading to testosterone synthesis and secretion by Leydig cells.

Follicle-stimulating hormone (FSH) increases the response of Leydig cells to LH by increasing the number of LH receptors expressed on Leydig cells.

The male Leydig cells in some species have also been shown to possess the biosynthetic machinery to manufacture testicular oxytocin de novo. Specifically, in rats who can synthesize Vitamin C endogenously, and in guinea pigs who (like humans) require an exogenous source of Vitamin C (sodium ascorbate) in their diets.[2]

Ultrastructure

The mammalian Leydig cell is a polyhedral epithelioid cell with a single eccentrically located ovoid nucleus. The nucleus contains one to three prominent nucleoli and large amounts of dark-staining peripheral heterochromatin. The acidophilic cytoplasm usually contains numerous membrane-bound lipid droplets and large amounts of smooth endoplasmic reticulum (SER). Besides the obvious abundance of SER with scattered patches of rough endoplasmic reticulum, several mitochondria are also prominent within the cytoplasm. Frequently, lipofuscin pigment and rod-shaped crystal-like structures 3 to 20 micrometres in diameter (Reinke's crystals) are found. These inclusions have no known function.[3][4] No other interstitial cell within the testes has a nucleus or cytoplasm with these characteristics, making identification relatively easy.

Development

Leydig cells form during the 16th and 20th week of gestation and are quiescent until puberty.

Pathology

Leydig cells may grow uncontrollably and form a Leydig cell tumour.

These tumours are usually benign. They may be hormonally active, i.e. secrete testosterone.

Additional images

References

  1. ^ synd/625 at Who Named It?
  2. ^ Kukucka Mark A, Misra Hara P (1992). "HPLC determination of an oxytocin-like peptide produced by isolated guinea pig Leydig cells: stimulation by ascorbate". Arch. Androl. 29 (2): 185–90. doi:10.3109/01485019208987723. PMID 1456839. http://informahealthcare.com/doi/abs/10.3109/01485019208987723. 
  3. ^ Al-Agha O, Axiotis C (2007). "An in-depth look at Leydig cell tumor of the testis". Arch Pathol Lab Med 131 (2): 311–7. PMID 17284120. 
  4. ^ Ramnani, Dharam M (2005-01-25). "Leydig Cell Tumor : Reinke's Crystalloids". http://www.webpathology.com/image.cfm?n=3&Case=38. Retrieved 2007-03-28. 

See also

External links








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