Adrenaline: Functions Of The Hormone Where It Is Produced

2024 Author: Rachel Wainwright | [email protected]. Last modified: 2024-01-15 19:51

The hormone adrenaline and its functions in the body

The content of the article:

Hormone functions
Where is it produced
Excessive production in the body
Insufficient production in the body
Video

The hormone adrenaline is an active compound, the synthesis site of which is the adrenal medulla. It is the main stress hormone along with cortisol and dopamine. The target in the human body is alpha (1, 2), beta (1, 2) and D-adrenergic receptors.

Synthesized in 1901. Synthetic adrenaline is called Epinephrine.

Adrenaline ensures the body's survival in stressful situations

Hormone functions

Adrenaline has a huge effect on the body. List of its functions:

Optimizes the operation of all systems in stressful situations, for which it is intensively produced in a state of shock, trauma, burns.
Leads to relaxation of smooth muscles (intestines, bronchi).
Dilates the pupil, which leads to an aggravation of visual reactions (reflex when feeling fear).
Reduces the level of potassium ions in the blood, which can lead to seizures or tremors. This is especially evident in the post-stress period.
Activates the work of skeletal muscles (blood flow, increased metabolism). With prolonged exposure, the effect is reversed due to muscle wasting.
It has a sharp stimulating effect on the heart muscle (up to the occurrence of arrhythmia). Influence occurs in stages. Initially, an increase in systolic pressure (due to beta-1 receptors). In response to this, the vagus nerve is activated, which leads to a reflex inhibition of the heart rate. The action of adrenaline on the periphery (vasospasm) interrupts the action of the vagus nerve and blood pressure increases. Beta-2 receptors are gradually included in the work. They are on the vessels and cause them to relax, which leads to a decrease in pressure.
Activates the renin-angiotensin-aldosterone system, resulting in an increase in blood pressure.
It has a strong effect on metabolism. Catabolic reactions are associated with the release of large amounts of glucose into the bloodstream (energy source). Leads to the destruction of proteins and fats.
Has a slight effect on the central nervous system (does not penetrate the blood-brain barrier). The benefit lies in mobilizing the reserve capacity of the brain (attention, reactions). The performance of the hypothalamus increases (it produces the neurotransmitter corticotropin), and through it the work of the adrenal glands (there is a release of cortisol - the "fear hormone").
Refers to anti-inflammatory and antihistamines. Its presence in the bloodstream inhibits the release of histamine (an inflammatory mediator).
Activates the coagulation system (increased platelet count, peripheral vasospasm).

Receptors influenced by adrenaline:

Types of receptors	Target	Localization	the effect
α ₁	Postsynaptic cell membrane	Arterioles, bladder, cervix and prostate	Vascular spasm leads to increased pressure. Relaxation of smooth muscles (easier urination).
α ₂	Presynaptic cell membrane. Feature - both adrenaline and norepinephrine act.	On nerve endings	Inhibition of the action of catecholamines (negative feedback).
β ₁	Postsynaptic cell membrane	Heart, kidneys	Increased heart rate and strength. Increased conductivity (the situation may be complicated by arrhythmia). Increased production of renin and, as a result, increased blood pressure.
β ₂	Presynaptic cell membrane.	Bronchioles, liver	Expansion of the bronchi. In the liver, it leads to processes associated with the breakdown of glycogen to glucose, after which it is excreted into the blood.
β ₃	Extra-synaptic localization	Adipose tissue	Breakdown of fats and increase in lipids in the bloodstream. This process is accompanied by the release of a large amount of energy.

Receptors are localized in almost all tissues. This explains the vast influence of adrenaline on the functioning of the body.

Where is it produced

The main place of synthesis is the adrenal medulla. Understanding the principle of construction allows you to understand the functions of the organ and explain the presence of certain symptoms. The adrenal glands are composed of a cortical and medullary substance. The bark has parasympathetic innervation, the medulla - sympathetic. The adrenal cortex consists of three zones:

Glomerular. Produces mineralocorticoids - aldosterone, corticosterone. The main action is aimed at regulating water and electrolyte balance. Regulation of kidney function.
Sheaf. The glucocorticoids cortisol and cortisone are the main hormones in this zone. An increase in the concentration of adrenaline leads to the activation of the hypothalamus (production of ACTH), which, in turn, leads to the release of cortisol.
Mesh. In this zone, sex hormones are produced - androgens and estrogens.

Catecholamines (adrenaline and norepinephrine) are synthesized in the chromaffin cells of the deepest layer of tissue - the brain. On histological preparations, these cells can be stained with potassium dichromate to obtain a reddish-brown color, hence their name. The precursors of epinephrine are tyrosine (phenylalanine) and methionine.

In the presence of a tumor (pheochromocytoma, neuroblastoma), hormones are produced outside the medulla, since they are hormone-producing. Features:

uncontrolled discharge;
a sharp increase in blood pressure with minimal stress (change in body position, walking);
"Turning off" the adrenal glands from the work (about six months is required to recover after surgical removal of the formation);
a large amount in the urine (not normally detected).

If a neoplasm in the abdominal cavity is suspected, compulsory CT / MRI examination.

Excessive production in the body

The concentration of adrenaline in the blood varies depending on the environment. The duration of action in the blood of catecholamines is 5-10 minutes. If, in the presence of concomitant pathologies or for other reasons, the indicators do not return to normal, this leads to the following consequences:

Myocardial hypertrophy - an increase in the volume of the heart muscle to the detriment of its function.
Uncontrolled metabolism (breakdown of proteins, fats, carbohydrates). This causes rapid and powerful weight loss.
Overstrain of the nervous system. Aggressiveness and irritability give way to distraction and nervousness. Obsessive-compulsive disorder may develop.
Paresis of the intestines, bladder, caused by prolonged relaxation of smooth muscles.
Ischemia of internal organs (liver, intestines, kidneys) due to vasospasm in the periphery and centralization of blood circulation (blood is directed to the heart, skeletal muscles, brain).
Jumps in blood pressure from low to high numbers, which are difficult to stop with medication.

A persistent increase in adrenaline is always secondary, i.e., acts as a concomitant component of the underlying disease.

Insufficient production in the body

Insufficiency of the adrenal glands is quite rare. It comes with the following features:

Prolonged depression that is not relieved by classical antidepressants. This is the reason for the so-called adrenaline addiction. When receiving a new dose of adrenaline (for example, when jumping with a parachute), the symptoms from the nervous system disappear for a while. Then they appear again, which makes the person again do something extreme.
Inappropriate response to a stressful situation (the fight-or-flight response does not work). The mobilization of body functions either does not occur, or occurs incorrectly (there is no centralization of blood circulation, stimulation of muscle tissue).
Decreased functioning of the hypothalamic-pituitary system.
Violation of sympathetic innervation. The vagus nerve dominates (i.e., parasympathetic innervation), which means the oppression of the work of all organs and systems. In particular, the process of catabolism (decay) is replaced by anabolism (synthesis) of complex chemical compounds from proteins, fats and carbohydrates. The resulting compounds are deposited in the liver.

Diagnosing adrenaline deficiency is extremely problematic. The patient's only complaint is constant fatigue. Often, this condition is treated incorrectly.