The Aldosterone Is a steroid hormone that is secreted by the adrenal glands, which is characterized by the presence of an aldehyde function (of the Aldehydes , Organic chemicals that are formed with the oxidation of the alcohols) in carbon 18.
The main function of aldosterone is to regulate mineral metabolism by facilitating the reabsorption of sodium in the kidneys, although it is also responsible for eliminating potassium.
Isolated first in 1953 and later synthesized in the laboratory by Derek Barton, the aldosterone has much to do with the electrolytes and with the water in the human organism.
Also, this hormone is in the group of mineralcorticoids, which are produced in the adrenal cortex which is also responsible for the manufacture of glucocorticoids. In addition, aldosterone is secreted into the glomerular zone, which is the outermost, thin layer of the cortex.
Aldosterone, in fact, is fixed in proteins, transported in the bloodstream, gets its metabolism in the liver and finally is expelled by the kidney, ie, the urine.
By going through all this process, this hormone makes that the exchange of potassium by sodium in several zones of the kidneys is much simpler, so that the sodium can be reabsorbed again and there is loss of sodium. Here there is also, in the cellular medium, a hydrogen ion transport.
Such a biochemical secretion of aldosterone would not be possible without the intervention of the adrenocorticotrope (better known and abbreviated as ACTH), which is a hormone of the pituitary gland by which this substance is guaranteed to be produced correctly.
If this does not happen, it is because there is too much or too little aldosterone in the human body, which results in severe health problems that greatly harm the quality of life of the human being.
As will be seen in the following pages, aldosterone is and has always been a very relevant hormone that has aroused the interest of scientists who have studied it (as Derek Barton) and synthesized by artificial means.
It will also delve deeper into what are their biochemical functions, what is behind their secretion in the adrenal glands and what are those diseases and clinical conditions that unfortunately arise from their abnormal functioning.
Aldosterone and the discovery of Derek Barton
Isolation of aldosterone first occurred in 1953, as already stated; This means that it was known of its existence before it was given a common name within the official nomenclature.
However, it was not until later that the British scientist Derek Harold Richard Barton (who lived from 1918 to 1998) managed to find a way to synthesize this hormone in controlled environments, that is, in the premises of his laboratory.
Apart from this successful finding that is the synthesis of aldosterone, Barton's academic career was also recognized in his work in organic chemistry, an area in which he devoted his greatest effort to the study and development of a conformational analysis , That is, a study of those organic substances whose properties are in function of the bonds between atoms, which have a three-dimensional orientation in their molecular structure.
A university professor in Glasgow and London, Barton had a long career as a professor and researcher, in which he studied the spatial configuration of atoms in organic molecules, which become more important when talking about saturated monocyclic systems.
At this point, it is not surprising that Barton understood the nature of aldosterone well to such a degree that the Nobel Prize for Chemistry won in 1969 with Odd Hassel.
Functions of aldosterone
As specified in previous paragraphs, this hormone has two fundamental purposes in the human body. The first one, which is the most important, is to make it easier to exchange potassium for sodium, while the second one, which is of less importance than the previous one, is to intervene in the cell so that it can be performed in a simple way. Transport of hydrogen ions.
You have to see each function separately. Note, for example, the first, involving potassium and sodium. Here permeability is increased in the cell membrane, but hydrolysis (the process in which the water unfolds the molecules of a certain chemical compound) and the conformation of the positive ions of sodium are also stimulated, which are reabsorbed and then secreted in the urine. The system can then reach its electrochemical equilibrium.
The second function, on the other hand, does not reach the complexity of the first, since a regulation of the bicarbonate levels is achieved through a secretion of hydrogen ions (particles, or rather hydrogen atoms that have a positive electric charge Which have lost their electron) that pass through the cells and obtain the balance of the system in a duct collector that is a kind of passage or tunnel, to call it in a way that is much more understandable to the reader.
Recent investigations point to the existence of six other aldosterone functions apart from the two that have just been described.
The additional workings of this hormone, as suggested in those scientific papers, are related to other areas of the human body at the cellular level and other systems that are not directly linked to the adrenal glands, which are the circulatory and the nervous, With special mention to the heart and the brain, respectively.
These six additional functions of aldosterone are, in particular, the following:
- Perform modulation of the reactivity of blood vessels. At this point there is dysfunction of the endothelium (that is the tissue that serves as a lining for the walls of organic cavities without contact with external areas, such as blood vessels) and also a stimulation of genes and proteins in the arteries of the heart As doctors say, the Coronary arteries ).
- Perform regulation of sodium transport in heart cells. In these cells there is, in fact, a stimulus that can be contemplated both in the accumulation of proteins and in the synthesis of messenger RNA (mRNA).
- Concrete the systematization of calcium entry into the myocytes, which are tube-shaped cells that are in the tissue of the muscles.
- Release arginine vasopressin (ADH, also known as Antidiuretic hormone , As it reabsorbs water by concentrating the urine) into the central nervous system.
- Stimulate the visceral motor system in its portion of the sympathetic nervous system, which causes blood pressure to rise and inflammatory responses to occur.
- Influence on the formation of neurons (ie, the Neurogenesis ) In the dentate gyrus (that part of the brain that is in the temporal lobe, in a region very close to the hippocampus).
Secretion of aldosterone
Every minute detail of the secretion of aldosterone is a complex subject on which rivers of ink have been spilled.
However, it is necessary for this hormone to explain the various ways in which its production is affected in the adrenal glands, since there are many biochemical interactions that in their most intimate aspects are related several organs of the human body, so this subject Encompasses more than just the endocrine system.
One of the most striking features of aldosterone is that it occurs during the day, that is, its production rate in the adrenal glands is diurnal.
In addition, the aldosterone is more secreted in the juvenile stage of the person and then decreasing its amount over the years, which is why its concentration in the elderly is much lower, which says why in the ages The more senile there are problems of low blood pressure as well as dizziness.
Another very unique feature of aldosterone is that it can be destroyed by the natural biochemical processes of the human being. This hormone, then, can be suppressed nothing more and nothing less than by the enzymes of the liver (the Hepatic enzymes ) As long as the flow of blood to this organ is reduced drastically through the constriction of the capillaries which irrigate it by the action of a hormone that is in fact known as angiotensin.
To these internal factors are added external factors no less important in the production of said hormone. Although this seems to go against nature, it is well known that aldosterone can change its levels with things as simple as sudden changes in the individual's posture and the sensation of pain.
The emotions produced by fear, stress or anger tend to cause very serious biochemical maladjustments. Anxiety causes the aldosterone to rise through the clouds.
It is also worth mentioning that aldosterone secretion may decrease with a constriction of the arteries, such as the carotid artery, and the involvement of regulatory hormones, such as ACTH.
On the opposite side you can see that aldosterone levels can rise with a low potassium in the blood and with the entry of serotonin. Hormones such as Dopamine and the Endorphin Serve to prevent aldosterone from being produced in the body.
Based on the above, it is very clear that aldosterone has receptors in other latitudes of the human body, mainly the brain and heart.
Consequently, there is a mutual relationship between the circulatory system, the nervous system And this hormone, whose values vary depending on various circumstances that may be of internal order (age, action and interaction with other hormones, constriction of blood vessels, etc.) or external order (strong emotions, for example).
Disorders associated with the secretion of aldosterone
However, not every sign of change in aldosterone levels means that everything goes on wheels. Although the amounts of this hormone fluctuate by natural causes, there are times when serious problems can occur because aldosterone also has harmful effects on health.
In addition to the diseases that will be discussed in this section, aldosterone can compromise the circulatory system simply by raising the blood pressure of the human being.
When it is expelled too much by the urine, the aldosterone can cause the organism to lose much potassium and magnesium, if that is added the potassium that is retained, with the risk of increasing their levels in dangerous amounts.
This results, in consequence, in alterations in the biochemical balance of the person and reveals a malfunction not only of the adrenal glands, but probably also of the circulatory system, by the constriction of the blood vessels.
By extension it can be said that the organs of the circulatory system suffer most from the mismatches in the levels of this hormone, when it is not produced properly.
Necrosis may occur in the myocardium, for example, in which this part of the heart deteriorates to such an extent that its cells die, which can lead to serious illnesses and even death. An early medical diagnosis will do much to prevent and alleviate coronary disorders like these.
If aldosterone is produced in excess, there may be different forms of hypertension, in addition to hypokalemia (loss of potassium, whose concentration drastically decreases because it is expelled from the urine) and generalized muscle weakness.
However, if this hormone becomes secreted in very few amounts, the dreaded heart failure can arise, that does not include arrhythmias (disorder in which the heart contracts at uneven and irregular rhythms).
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