Releasing hormones are human neurohormones that synthesize the nuclei of the hypothalamus. They inhibit (statins) or stimulate (liberins) the production of tropic pituitary hormones. The work of the endocrine glands is activated, and the regulation of their secretion of hormones occurs. The higher parts of the central nervous system and the endocrine system are in close connection due to releasing hormones.
Hypothalamus functions
One of the important components of the endocrine system responsible for the production of hormones is the hypothalamus. Substances produced by the hypothalamus are hormones involved in the metabolic processes of the body.
In the hypothalamus there are nerve cells that provide the production of the necessary substances needed by the body for normal functioning. These cells are called neurosecretory. Their task is to receive impulses that transmit different parts of the nervous system. The selection of elements occurs through axovasal synapses.
Hypothalamus-produced releasing hormonesor, as they are otherwise called, statins and liberins, are essential for the normal functioning of the pituitary gland. By their chemical nature, they are peptides. Thanks to chemical and nerve impulses, they are synthesized, they are transported to the pituitary gland by blood through the hypothalamic-pituitary system.
Classification of hormones
Let's consider the most famous releasing hormones:
- Inhibiting the secretory function of the pituitary gland - we are talking about somatostatin, melanostatin, prolactostatin.
- Stimulating - we are talking about melanoliberin, prolactoliberin, folliberin, luliberin, somatoliberin, thyroliberin, gonadoliberin and corticoliberin.
The listed substances, or rather some of them, can be produced by other organs, not only the hypothalamus (for example, the pancreas).
Statins and liberins
The functioning of the pituitary gland directly depends on them. They also affect the functioning of peripheral endocrine glands:
- thyroid;
- ovaries in girls;
- male testicles.
Statins and liberins that are best known:
- dopamine;
- gonadoliberin (luliberin, folliberin);
- melonostatin;
- somatostatin;
- thyreoliberin.
Secretion of luteinizing and follicle-stimulating hormones by the pituitary gland is provided by gonadoliberins.
Gonadoliberins also affect the activity of androgens in men, contribute to an increase in activitysperm count and libido levels.
And in women, neurohormones are responsible for the menstrual cycle, and the amount of hormones varies depending on the phase of the cycle.
Insufficient production of releasing hormones often causes infertility and impotence.
Characterization of hormones
The hormone corticoliberin, which is responsible for feelings of anxiety, is produced by the hypothalamus. This is another important releasing factor that acts in conjunction with pituitary hormones and affects the functioning of the adrenal glands. People with a lack of this hormone often suffer from hypertension and adrenal insufficiency.
Gonadoliberin - a hormone that enhances the production of gonadotropins - is also a product of the hypothalamus. It is also called gonadotropin-releasing hormone.
The normal functioning of the genital organs cannot do without GnRH. It is this hormone that is responsible for the natural course of the menstrual cycle in women. With its participation, the process of maturation and release of the egg takes place. This hormone is responsible for libido (sex drive). With insufficient production of this hormone by the hypothalamus, women often develop infertility. What other releasing hormones are there?
Somatoliberin
Most prominent in childhood and adolescence. Its main property is the normalization of the growth processes of organs and body systems. From its development depends on the full development and formation of the child. Insufficient production of this hormone by the hypothalamus can lead to dwarfism(dwarfism).
Prolactoliberin
Its production is most active during the period of gestation and throughout the entire period of feeding the child by the mother. This releasing factor normalizes the production of prolactin, which forms the ducts of the mammary glands.
Prolactostatin
Prolactostatin is a subclass of statins produced by the hypothalamus and is responsible for inhibiting prolactin.
Prolactostatins include:
dopamine;
somatostatin;
· Melanostatin.
Their main action is aimed at suppressing the tropic hormones of the pituitary and hypothalamus.
Melanotropin-releasing hormone
Melanoliberin influences the process of melanin production and division of pigment cells. It also affects the elements of the PRD of the pituitary gland.
Influences human neurophysiological behavior. It is used to relieve depression and treat parkinsonism.
Thyrotropin-releasing hormone (TRH)
Thyrotropin-releasing hormones of the hypothalamus also include thyroliberin. It promotes the production of thyroid-stimulating hormones by the adenohypophysis.
Slightly affects the production of prolactin. Thyroliberin provides an increase in the concentration of thyroxine in the blood.
CNS has a great influence on the processes of hormone production. The neurosecretory cells of the regulatory system are responsible for the production of neurohormones.
The main functions of liberins
These are releasing hormoneshypothalamus. Perform regulatory functions. Gonadoliberins normalize the functioning of the sexual sphere of women and men.
They are responsible for the reproduction of follicle-stimulating hormones and affect the functioning of the testicles and ovaries.
Such a component as luliberin has a separating effect on ovulation, forming the possibility of conceiving a fetus.
In women who are indifferent to intimate life, luliberin and folliberin are produced in insufficient quantities.
There are also releasing factors related to the middle lobe of the hypothalamus, but their connections with elements of the pituitary and adenohypophysis have not been studied.
Hormone-releasing hormone agonists: drugs
As already noted, these hormones are produced by the hypothalamus. When it is required to stimulate the ovaries, for example, before the IVF procedure, agonists or analogues of releasing hormones are used. That is, they have the same effect on the body as their own hormone.
But the likelihood of adverse reactions from the female body is high. This is due to the decrease in estrogen levels. The most common occurrences include:
- headache;
- excessive sweating;
- tides;
- dry vagina;
- mood swings;
- depressive states.
The following drugs are used:
- "Diphereline" is an artificial decapeptide, an analogue of the natural releasing hormone.
- "Decapeptyl" contains triptorelin,artificial analogue of GnRH. The half-life is longer. Often used in artificial insemination.
- "Lukrin-depot" - leuprorelin. It has antiestrogenic, antiandrogenic effects, treats endometriosis, hormone-dependent tumors - prostate cancer, uterine fibroids. "Lukrin-depot" reduces the concentration of testosterone in men, estradiol in women, in addition, it inhibits the incretion of FSH and LH by the pituitary gland.
- The action of the drug gradually restores the physiological secretion of hormones.
- "Zoladex" is a synthetic analogue of the natural releasing hormone (LH). Often used in IVF. Reduces the concentration of estradiol in the blood, this is due to the suppression of LH secretion of the anterior pituitary gland.
We have considered releasing hormone agonists.
Antagonists
Because estradiol is extremely elevated when taking HRT agonists, a surge of luteinizing hormone can occur. This leads to premature ovulation and egg death. To prevent this, releasing hormone antagonists are used. As a result of their action, the pituitary gland can be stimulated again. Ovarian hyperstimulation syndrome does not manifest itself, and in fact it often happened due to the long-term use of GnRh agonists. Administer five days after starting FSH.
For the therapy to be successful, all prescriptions should only be carried out by a specialist.
