A Sertoli cell is a kind of cell, that secretes chemical substances necessary for the development and management of germ cells, resulting in the sperm cell production. It also blocks the interaction of blood with germ cells to prevent any damages done by the body immunity to its own germ cells and contrariwise it prevents the germ cells to provoke an immunological reaction in its own body.
One of the main parts of a testicle is the seminiferous (germinal) epithelium of seminiferous tubules responsible for the sperm cells production. There can be found very specific type of cells with utmost importance for development of sperm cells at different stages, called Sertoli cells. Sertoli cells have fundamental importance to the development and maintenance of spermatogenesis. There is a proportional numerical relationship of Sertoli cells to the sperm cell production. Sertoli cells secrete signalling molecules that promote sperm production and can control whether germ cells (“young” sperm cell stages) live or die. Sertoli cells take elongate form branching all stages of developing sperm cells, they physically extend themselves around the germ cells.
Other function of Sertoli cells
Sertoli cells do not only control the process of spermatogenesis, but they are also responsible for creating so called immunologically privileged area in the testicles. It means, that Sertoli cell manage to keep blood separated from seminiferous tubules through the connection between them, called tight junction. Tight junction keeps bloodborne substances from reaching germ cells, so all stages of germ cells are protected from the body immunity. Tight junction also keeps surface antigens found on developing germ cells from eluding into the bloodstream so no autoimmune reaction could happen. Since Sertoli cells form the block between the blood and lumen of seminiferous epithelium, they are also in control of the entry and exit of nutrients, hormones and other chemicals into the tubules of the testis.
Secretory function of Sertoli cells
Following substances are secreted by Sertoli cells to manage the sperm production:
1. Anti-Müllerian hormone (AMH)
2. Inhibin and activins
3. Androgen binding protein (also called testosterone binding globulin)
Sertoli cells are required for male sexual development. Once fully differentiated, the Sertoli cell is unable to proliferate. Therefore, once spermatogenesis has begun (during puberty), no more Sertoli cells are created. Recently however, some scientists have found a way to grow these cells outside of the body. This gives rise to the possibility of repairing some defects that cause male infertility.
Management of Sertoli cells
Sertoli cells itself need an activation signal to start working properly. The triggering hormone activating Sertoli cells is called follicle stimulating hormone (FSH). FSH belongs to the group of hormones called gonadotropins, by the name it is clear, that the purpose of this group of hormones is to stimulate the function of gonads. In a male organism this hormone influences the sperm cell production through Sertoli cells.
Reproduction disorders related to Sertoli cells
1. Sertoli cell-only syndrome
2.Sertoli cell tumour
Complete absence of sperm in the ejaculate of a man.
In the case of cryptorchidism one or both testes are absent from the scrotum. It is is the most common etiologic factor of azoospermy in the adult.
A class of sexual disorders defined as the subjective lack of normal ejaculation.
A medical condition impairing the function of the thyroid.
A genetic condition where the primary symptom is a failure to start puberty or a failure to fully complete puberty.
Antibodies that bind to sperm, inhibiting their movement, stopping recognition and entry into the egg.
Cancer that develops in the testicles.
Absence of sperm in the ejaculate despite normal spermatogenesis, caused by an obstruction of the genital tract.
An inflammation of the testes, involving swelling and heavy pains.
Emergency medical condition occurring when the spermatic cord twists and cuts off the testicle's blood supply.
The inability of the testicles to produce sperm or testosterone.
The absence of any developmental stage of sperm cell in the testes.
Male gonads which produce both sperm and androgens, such as testosterone, and are active throughout the reproductive lifespan of the male.
Process in which spermatozoa are produced from male primordial germ cells in testicles by way of mitosis and meiosis.