Vasopressin (antidiuretic hormone): these are its functions

Hormones are chemical compounds that, when released by the endocrine glands into the blood or system nervous system of living beings, exert modulating effects on the functions of other cells and structures bodily.

One of the most relevant and well-known human hormones is vasopressin or antidiuretic hormone, which is essential for fluid retention or the stress response, among other phenomena. In this article we will analyze the properties and functions of vasopressin.

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What is vasopressin?

Vasopressin is also known as “argipressin”, “arginine vasopressin” and “antidiuretic hormone”. As the latter name suggests, this hormone fulfills functions related to the reabsorption of water molecules through the kidneys and with the decrease in the amount of urine accumulated in the organism.

It is an oligopeptide, that is, a molecule made up of the union of a small number of amino acids, specifically 9. In contrast, polypeptides are groups of between 10 and 100 amino acids, while "proteins" are used to refer to groups of more than 100 such molecules.

Specifically, vasopressin contains an amino group (-NH2), cysteine ​​(Cys), tyrosine (Tyr), phenylalanine (Phe), glutamine (Gln), asparagine (Asn), proline (Pro), arginine (Arg) and a carboxyl group (-COOH).

Vasopressin is secreted by the neurohypophysis., the posterior lobe of the pituitary gland, in response to changes in osmotic concentration and blood volume. Although most of the vasopressin we produce is released into the bloodstream, its effects on the brain also explain some of its functions.

Other pituitary hormones

The pituitary or pituitary gland is one of the major endocrine glands.. It fulfills an intermediary function between the hypothalamus, which initiates the secretion of hormones, and the rest of the endocrine system by sending biochemical signals.

This structure is composed of two lobes: the anterior or adenohypophysis and the posterior or neurohypophysis. While the posterior pituitary stores the hormones vasopressin and oxytocin (related to motherhood and orgasm), the anterior pituitary gland secretes thyrotropin-releasing hormones, corticotropin, gonadotropins, and growth.

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Functions of this hormone

The main functions of vasopressin they are associated with its ability to regulate the activity of the kidneys; however, this hormone also has effects on other body systems, including the cardiovascular and central nervous systems.

1. Fluid retention and reabsorption

Vasopressin increases the permeability of kidney cells, increasing the amount of water they absorb; this function is called “antidiuresis”. Such a process also implies an increase in the concentration of urine due to the lower availability of liquid in the excretory system.

On the other hand, antidiuretic hormone also reabsorbs urea, the main chemical compound in urine, made up of waste products from the body. This prevents the frequency of urination from being excessive.

2. Maintenance of homeostatic balance

Homeostasis (self-regulation of the internal environment of organisms) depends on a large number of factors; among these is the activity of vasopressin. If homeostatic mechanisms fail, problems such as dehydration and acidosis can occur.

This hormone helps maintain electrolyte balance in the bloodstream by retaining and reabsorption of adequate amounts of water, glucose, and sodium, among other chemical compounds relevant to the functioning of the body.

3. Increased blood pressure

Another of the most prominent effects of vasopressin is the increase in blood pressure. Said function occurs as a consequence of the vasoconstrictive properties of this hormone, which have a moderate intensity. The potentiating role of vasopressin on hormones and neurotransmitters associated with stress is also important in explaining this effect.

4. Modulation of the stress response

Although not fully confirmed by scientific research at this time, there is strong evidence that that vasopressin has a modulating effect on the body's response to stressful situations (or anxiogenic).

Antidiuretic hormone regulates the release of corticotropin-releasing hormone, also called "adrenocorticotropic hormone-releasing hormone." This compound promotes secretion of corticosteroids such as aldosterone and cortisol, mainly associated with vasoconstriction and the stress response by the adrenal gland.

5. Reduced sensation of pain

In recent years, the involvement of vasopressin in the modulation of the pain sensations. It is believed that this hormone could act as an analgesic; this would imply that, when released under certain conditions, vasopressin would have reinforcing effects due to the positive sensations associated with its secretion.

6. Formation of sexual and social bonds

Rodent studies suggest that vasopressin release also acts as a enhancer of social ties, especially those of couples. In humans, these effects have been found mainly in males and are related to the direct release of antidiuretic hormone in the reward circuits of the central nervous system.

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