Two anatomical components are distinguished in the kidney - this is the cortical and medulla. Each of them produces certain groups of hormones.
Aldosterone - what is it?
Aldosterone is a hormone synthesized by the cortical substance of the kidney, the function of which is to delay sodium ions and excrete potassium ions. Mineralcorticoid is synthesized in the glomeruli of the cortical substance of the kidney. This is the only mineral corticoid that enters the bloodstream. The regulation of its production depends on renin and angiotensin, mainly angiotensin-2. Therefore, as a result of their relationship, the renin-angiotensin-aldosterone system (RAAS) occurs.
This system regulates the level of volume and pressure in the bloodstream, that is, the water-salt balance and hemodynamics. Renin enters the blood under conditions of lowering blood pressure, mechanisms that ensure a decrease in the concentration of sodium ions in the blood and a simultaneous increase in the level of potassium, acting as antagonists, automatically start. At this time, the protein angiotensin breaks down to form angiotensin-1, which, under the influence of enzymes, turns into angiotensin-2. This protein contributes to spasm of the vascular bed, which stimulates the synthesis of aldosterone. As a result, the level of blood pressure rises . What is it - aldosterone is of interest to many.
What happens during various failures?
When failures occur in this system, pathological processes begin, leading to overproduction or, conversely, to insufficient production of the mineral corticoid (hyperaldosteronism and aldosteronopenia).
RAAS activation occurs in the following situations:
- Decreased pressure in the renal blood vessel system.
- Lack of salt elements of the blood.
Stressful and extreme situations entail an increase in the tone of the sympathetic nervous system.
Hormone function
There are so-called target organs of this hormone:
- The kidneys.
- Vessels.
- Brain.
Aldosterone (what is it, we explained) affects the quantitative and qualitative composition of urine. As mentioned above, the hormone contributes to the retention of sodium ions, but potassium, on the contrary, removes from the body, reducing its concentration.
It affects vascular elements through receptors, leads to an increase in the tone of the smooth muscle component of the vascular wall as a result of blood pressure in the peripheral parts of the bloodstream.
It has an effect on brain cells. Aldosterone causes a jump in blood pressure by the activating effect of the central nervous system on the vital vasomotor center.
Sodium retention occurs not only in the renal elements, but also in the cells of the gastrointestinal tract. In glandular skin formations, on the contrary, its concentration decreases due to a change in the qualitative composition of sweat.
The effect of this mineralcorticoid is:
- An increase in the level of sodium ions in blood plasma.
- A decrease in the concentration of potassium ions.
- Increased blood pressure.
in addition, the hormone aldosterone activates the synthesis of collagen fibers, which is especially noticeable with ischemia of the heart muscle or with manifestations of arterial hypertension. Thus, he takes part in the formation of the connective tissue framework of the vascular system and the entire human body.
Hormone norm
The norm of aldosterone and its physiological significance are variable, but on average its concentration in an adult is from 100 to 400 picomoles / liter, and in newborns from 1060 to 5480 picomoles / liter, and in the age before the first six months it is slightly less and ranges from 500 -4450 picomole / liter. However, we must remember that each laboratory gives its own standard values for hormones, so the results may vary.
Why detect the hormone aldosterone?
The goal of determining hormone levels
It consists in the following:
- Find out the value of the concentration of this mineralcorticoid, as well as other hormonal compounds.
- Screening study for primary hyperaldosteronism (Conn syndrome).
Alarms for determining mineralcorticoid concentration
These include:
- High blood pressure or low salt levels.
- Drug resistance in the treatment of hypertension or a significant jump in blood pressure in young people.
- Suspected adrenal hypofunction.
The functions of hormones in the human body are extensive.
Preparing for a hormone test
It is imperative to conduct the following activities before analysis:
- Limiting the use of carbohydrate-containing food products (bakery products, sugar) for from two weeks to a month before the study.
- The use of diuretics and antihypertensive drugs, steroid drugs, as well as oral contraceptives and estrogens is prohibited for 14-30 days before the procedure.
- Exclude renin inhibitors one week before the study.
- Limit physical and emotional stress three days before the test.
- It is strictly forbidden to smoke for at least 3-5 hours before the delivery of venous blood.
And if blood aldosterone is elevated?
Hormone-related diseases
There is a division into primary and secondary aldosteronism.
Primary is represented by diseases that have arisen under the influence of the following reasons:
- Conn's syndrome.
- Malignant and benign neoplasms that activate the synthesis of mineralcorticoid.
- Hyperplastic processes of the glomerular apparatus and the adrenal gland.
- Heredity.
Causes of secondary hyperaldosteronism:
- Chronic heart failure.
- Cirrhosis of the liver in combination with ascites resulting from cirrhosis.
- Nephrotic edematous syndrome.
- Barter Syndrome.
- The dehydration caused by massive blood loss or excessive loss of intra- and extracellular fluid.
- Malignant renal hypertension.
A reduced level of the hormone is observed with:
- Chronic adrenal insufficiency.
- Waterhouse-Fridericksen Syndrome.
- Congenital form of adrenal cortical dysfunction.
We have described the hormone aldosterone. What is it and how to monitor its level you now know.