Leydig cell

Leydig cell
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
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 can secrete testosterone and are often closely related to nerves. Leydig cells have round vesicular nuclei and an eosinophilic cytoplasm.

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.

Ultrastructure

Leydig cells are polygonal, eosinophilic cells with a round vesicular nucleus and contain lipid droplets. They contain abundant smooth endoplasmic reticulum, which accounts for their eosinophilia. No rough endoplasmic reticulum is present. 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.^[2][3]

Development

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

Pathology

Micrograph of a Leydig cell tumour. H&E stain.

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

Section of a genital cord of the testis of a human embryo 3.5 cm. long.

Intermediate magnification micrograph of a Leydig cell tumour. H&E stain.

High magnification micrograph of a Leydig cell tumour. H&E stain.

References

See also

• Sertoli cell
• Sertoli-Leydig cell tumour

External links

• Histology at BU 16907loa
• Reproductive Physiology
• Diagram at umassmed.edu