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 hormones are regulated by them. The higher departments 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.
The releasing hormones produced by the hypothalamus, or, as they are called in other words, 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 by blood through the hypothalamic-pituitary system.
Hormone classification
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, follyberin, luliberin, somatoliberin, tyroliberin, gonadoliberin and corticoliberin.
The listed substances, more precisely 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 gland;
- ovaries in girls;
- testicles in the male.
Statins and liberins that are best known:
- dopamine;
- gonadoliberin (luliberin, follyberin);
- melonostatin;
- somatostatin;
- thyroliberin.
The secretion of luteinizing and follicle-stimulating pituitary hormones is provided by gonadoliberins.
The activity of androgens in men is also affected by gonadoliberins, contribute to an increase in sperm activity and the level of libido.
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.
Hormone Characterization
The hormone corticoliberin, responsible for feelings of anxiety, is produced by the hypothalamus. This is another important releasing factor, acting in conjunction with the pituitary hormones and affecting the adrenal glands. People with a deficiency 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 genitals cannot do without gonadoliberin. It is this hormone that is responsible for the natural course of the menstrual cycle in women. With his participation, the process of egg maturation and release 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 rapidly stands out in childhood and adolescence. Its main property is the normalization of the growth processes of organs and body systems. The full development and formation of the child depends on its development. Inadequate production of this hypothalamic hormone can lead to nanism (dwarfism).
Prolactoliberin
Its development most actively occurs 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 refers to a subclass of statins produced by the hypothalamus, which is responsible for the inhibition of prolactin.
Prolactostatins include:
Dopamine
Somatostatin;
Melanostatin.
Their main action is aimed at suppressing the tropic hormones of the pituitary and hypothalamus.
Melanotropin-releasing hormone
The process of melanin production and the separation of pigment cells is influenced by melanoliberin. It also acts on the elements of the pituitary gland.
It affects the neurophysiological behavior of a person. It is used to relieve depressive conditions and treat parkinsonism.
Thyrotropin-releasing hormone (TRH)
The thyrotropin-releasing hormones of the hypothalamus also include tyroliberin. It promotes the production of thyroid-stimulating hormones of the adenohypophysis.
To a small extent, it affects the process of prolactin production. Tiroliberin provides an increase in the concentration of thyroxine in the blood.
The central nervous system has a great influence on the production of hormones. Neurosecretory cells of the regulatory system are responsible for the production of neurohormones.
The main functions of liberins
These are releasing hormones of the hypothalamus. Perform regulatory functions. Gonadoliberins normalize the functioning of the genital area of women and men.
They are responsible for the reproduction of follicle-stimulating hormones and affect the work of the testes and ovaries.
Such a component as luliberin has a detached effect on ovulation, forming the possibility of conception of the fetus.
In women who are indifferent to intimate life, luliberin and follyberin are produced in insufficient quantities.
There are also releasing factors related to the middle lobe of the hypothalamus, but their compounds with the elements of the pituitary and adenohypophysis are not studied.
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 there is a high probability of the development of adverse reactions from the female body. This is due to a decrease in estrogen levels. The most common phenomena include:
- headache;
- excessive sweating;
- tides;
- dry vagina
- mood swings;
- depressive states.
The following drugs are used:
- "Diferelin" is an artificial decapeptide, an analogue of natural releasing hormone.
- Decapeptil contains triptorelin, an artificial analogue of GnRH. The half-life is longer. Often used in artificial insemination.
- "Lucrin Depot" - leuprorelin. It has an anti-estrogenic, anti-androgenic effect, cures endometriosis, hormone-dependent tumors - prostate cancer, uterine fibroids. "Lucrin-depot" reduces the concentration of testosterone in men, estradiol in women, in addition, inhibits the growth of pituitary gland FSH, LH.
- The action of the drug gradually restores the physiological secretion of hormones.
- Zoladex is a synthetic analogue of 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 reviewed drugs releasing hormone agonists.
Antagonists
Since estradiol is extremely increased when taking releasing hormone agonists, a sharp release of luteinizing hormone can occur. This leads to premature ovulation and egg death. To prevent this, apply releasing hormone antagonists. As a result of their action, the pituitary gland can again be stimulated. Ovarian hyperstimulation syndrome does not manifest itself, and it often happened because of the prolonged use of GnRh agonists. It is administered five days after the start of follicle-stimulating hormone use.
In order for therapy to be successful, only a specialist should carry out all drug prescriptions.