Gonadotropic hormones and their functions

Hormones are different organic substances that can affect the vital activity of the human body. Gonadotropic hormones affect the functioning of the reproductive system. They are synthesized in the anterior pituitary gland and from there are secreted into the blood.

Hormones of the anterior lobe of the pituitary gland

The pituitary gland is divided into two parts: the front and the back. In the front, hormones are directly synthesized and released into the blood. In the posterior lobe of the pituitary gland they come from the hypothalamus and are secreted into the blood only under certain circumstances.

Gonadotropic hormones of the pituitary gland stimulate the sexual glands. These include:

  • FSH - follicle-stimulating hormone. It promotes oogenesis and spermatogenesis. It is a complex protein( glycoprotein), which consists of amino acids, connected with carbohydrates.
  • LG is a luteinizing hormone. Promotes the release of the egg from the ovary, affects the secretion of sex hormones( estrogen, progesterone), in men causes the secretion of androgens. The amount of the hormone changes during one menstrual cycle, proportional and synchronous secretion of a certain amount of FSH and LH occurs.

The production of hormones is carried out in gonadotrophs( basophilic cells) of the adenohypophysis. They account for about 15% of all cells in the anterior lobe.

Hormone pregnancy - hCG

When fertilization and implantation of the fetal egg in the wall of the uterus in the body, women begin to develop specific pituitary gonadotropic hormones, represented by the chorionic gonadotropin.

The function of the hormone is to maintain the work of the yellow body( the release of estrogen and progesterone) until the placenta ripens. It has a high luteinizing effect on the body, which largely surpasses FSH and LH.

Structural features of hormones

Biological activity of hormones provides their unique structure, which includes two subunits. The first, a-subunit, has an almost identical structure in all gonadotropic hormones, while the b-subunit provides a unique effect of the hormone.

Separately, these subunits do not have any effect on the body, but when they combine, their biological activity and influence on the vital processes of the body, in particular, the reproductive system, are ensured. Thus, gonadotropic hormones have an important effect not only on the sexual sphere, but also on the endocrine processes, and on the regulation of the hormonal balance.

How hormones affect the body

Since ancient times, scientists have sought to study the biological activity of hormones and their effects on the human body. Gonadotropic hormones exert a great influence on the processes of vital activity of the human body. Therefore, a study of the mechanism of their action is a very important and interesting question. When carrying out studies with labeled hormones, it was possible to establish that cells are able to recognize a certain hormone, and bind only to certain cells.

The process of binding to the cell is carried out by the presence in the membrane or inside the cell of the protein molecule - the receptor. Intracellular reception refers to steroid hormones, since they have the property of penetrating into the cell and influencing its work. Membrane reception is characteristic of protein hormones that bind to the membrane membrane of the cell.

The binding of a hormone to a receptor protein contributes to the formation of a complex. This stage passes without the participation of enzymes and is reversible. Steroid hormones penetrate the cell, bind to the receptor. After transformation, the formed complex penetrates into the nucleus of the cell and promotes the formation of a specific RNA, in the cytoplasm of which the synthesis of enzymatic particles that cause the action of hormones on the cell occurs.

Gonadotropic hormones: functions and effects on the processes of the reproductive system

FSH is most active in females. It stimulates the growth of follicular cells, which under the influence of GCICs turn into vesicles and mature before the ovulation stage.

Under the influence of FSN, there is an increase in the weight of the ovaries and testes. However, even with the artificial introduction of a synthetic hormone, it is impossible to cause the development of interstitial tissue, which affects the secretion of androgens of the testicular nature.

The GSIC is responsible for ovulation and formation in the ovaries of the yellow body. Also, together with follicle-stimulating hormone, it affects the secretion of estrogens. Under the influence of a hormone that stimulates interstitial cells, there is an increase in the organs responsible for secondary sexual characteristics.

Biological action LTG

LTG is very similar to the growth hormone. After carrying out laboratory tests, it was found that they are in the same molecule, therefore, one can not separately separate each of these hormones. The functions of LTG include the secretion of milk and progesterone. It is important to note here that these processes are caused by the interaction of a large number of hormones, since when the body exerts only LTG, these functions do not appear.

So, for the allocation of milk, the following hormones are needed:

  • FSH and GSIC - cause the secretion of estrogens in the ovaries;
  • under the influence of STH and estrogens, the growth of milk ducts occurs;
  • LTG causes progesterone secretion in the yellow body;
  • progesterone stimulates the full development of the mammary gland on the alveolar-lobe level.

Gonadotropic hormones require regular interaction to ensure the full functioning of the body and all its systems. That is why the separate influence of each of them( in the case of the introduction of synthetic hormones) does not cause the expected reaction of the organism.

Hypothalamus hormone

The hypothalamus secretes a gonadotropin releasing hormone into the blood. It has a polypeptide structure and affects the secretion of pituitary hormones. It has a greater effect on luteinizing hormone, and then on follicle-stimulating hormone. GnRH is produced in clearly defined time intervals, in women they range from 15 to 45 minutes( depending on the cycle), and in men the hormone is secreted every 90 minutes.

With the artificial introduction of a synthetic hormone by means of a dropper, the functions of hormone secretion are broken, which consist in a short-term increase in secretion, and then in the complete cessation of the production of gonadotropic hormones in the anterior pituitary gland.

The process of action of gonadoliberin on the body

GnRH provides stimulation of the anterior pituitary part whose cells( gonadotropins) have a specific gonadoliberin receptor for the secretion of follicle-stimulating and luteinizing hormones, which in turn affect the functioning of the gonads.

FG stimulates the maturation of spermatozoa and eggs, LH influences the secretion of sex hormones( estrogen, progesterone, testosterone).Under the influence of sex hormones, cells of the reproductive system mature and become ready for fertilization.

With excessive rapidity of the processes of oogenesis and spermatogenesis, inhibin, which affects gonadotropic hormones of the anterior lobe of the pituitary gland, is released, which contributes to slowing the maturation of the reproductive cells by acting on the follicle-stimulating hormone.

What is used for gonadotropic drugs

Increasingly in medical practice, treatment is encountered through the introduction of artificial hormones. With some endocrine diseases or disorders of the human reproductive system, gonadotropin hormone preparations are used. Their introduction to a certain extent affects the production of sex hormones and the processes occurring in the body.

In the case of a violation of the synthesis of gonadotropic hormones, certain endocrine disorders can develop( miscarriages in the first trimester, sexual immaturity, sexual infantilism, Simmonds disease and Shihan syndrome).

To neutralize pathology data, a blood test and an analysis of its hormonal composition are performed. Then drugs are prescribed that are necessary to restore the proper balance of hormones and, accordingly, the regulation of vital processes in the body.