If our body had a motto, it would sound like this: “Stability, stability and stability again!»
Our body is terribly conservative and incredibly self-sufficient. He does not tolerate any changes and desperately resists any external influence that can disturb the balance established by nature. All the conservative parties of the world, from the British tories to the Brazilian progressives, together will not be able to outdo any living organism in conservatism. That’s it.
Hormones-conservatives that maintain the constancy of the internal environment of the body, it is the most responsible and most conscious of hormones. These supporters of the inviolability of the primordial foundations ensure the normal functioning of the body, that is, perform The most Important Task.
Actually, if we are to be honest, the conservatives are all hormones without exception, because in the development of a normal physiological amount, they provide this very normal activity.
What is the normal functioning of the body?
This is a natural, not disturbed metabolism.
In this Chapter, we will consider only those hormones that are directly involved in the regulation of metabolism and energy (this name will be complete).
And what is metabolism?
It is often possible to meet such definition: “metabolism is a set of the processes occurring in an organism at assimilation of food”. This definition is incorrect because it is incomplete, and half-truths are known to be even worse than outright lies. Well I learned the body food – what next?
Here’s the correct definition: “metabolism (about energy, we will not constantly mention, but in the mind it will keep) is a set of chemical reactions that occur in a living organism to maintain life.”
Feel the difference?
Often you can hear such a complaint: “I have a wrong metabolism and therefore…”. This is stupid. Metabolism cannot be “right”or” wrong.” Wrong, from our point of view, the exchange of plants – they convert solar energy into carbohydrates. Instead of the word “wrong” it is necessary to use the word “broken”. Metabolic disorders are, alas.
Metabolism and energy, which is scientifically called “metabolism”, consists of two interrelated processes: plastic metabolism or “assimilation”, the essence of which is the synthesis of organic substances in the body using external sources of energy (food) and energy metabolism or “dissimilation” – the process of disintegration of organic substances with the release of the desired body energy.
Plastic metabolism is also called anabolism (hence “anabolic steroids”), and energy – catabolism.
By the way, metabolism and energy and the ability to reproduce themselves are specific features of living matter that distinguish the living from the inanimate. In an inanimate system, no exchange and reproduction can occur.
In the process of metabolism received in the body substances are converted into their own tissue substances and in the final products of metabolism, excreted from the body into the external environment. These transformations release and absorb the energy necessary for the body to function.
The metabolic process can be divided into three stages. This separation is conditional, because the exchange proceeds in a very complex way.
The first stage of metabolism is the breakdown of proteins, fats and carbohydrates using enzymes to water– soluble amino acids, mono-and disaccharides, glycerol, fatty acids and other compounds, as well as their absorption into the blood. That is, the first stage is digestion, digestion of food in the gastrointestinal tract. Conventionally, digestion can be described as the preparation of building materials for the body, because in the process of digestion of complex substances coming from the environment, are disassembled into small components-“bricks”.
Once the building materials are prepared, they must be delivered to the construction site, or rather – to places in the body of a great many.
The second stage of metabolism involves the transport of nutrients by the blood to the tissues and the exchange occurring in the cells, which results in the splitting of the resulting substances to the final products. Some of these products are used for the synthesis of biologically active substances and cell reproduction. The splitting of substances is accompanied by the release of energy necessary to ensure the process of vital activity of the body.
The third stage of metabolism is the excretion of its final products into the external environment as part of urine, feces, sweat, as well as through the lungs with exhaled air.
Figuratively speaking, the following stages – procurement of material, construction, garbage disposal. And all stages are under the vigilant and vigilant control of hormones, which are vigilant to ensure that all processes proceed as expected.
What do you think – at what stage of metabolism disorders will be the most dangerous for the body? This question is student, and therefore-provocative.
The most frequent answer is on the second. At first glance, it is logical, because the second stage looks the most responsible. In fact, the most dangerous for the body will be violations occurring at the third stage of metabolism, at the conditional “stage of garbage collection”. If the “garbage” is not taken out in a timely manner and in full, it will begin to poison the body. (Those who want to delve deeper into this sad topic can type in the search engine “chronic kidney failure.”)
Obesity from the biological point of view is the predominance of plastic metabolism over energy (anabolism over catabolism), and exhaustion – the predominance of energy metabolism over plastic (catabolism over anabolism).
Metabolism can be divided into three parts by substances involved in the processes – protein, carbohydrate, fat.
Now you know enough about metabolism to be able to move on to the hormones that regulate it.
We will start with carbohydrate metabolism, as the most popular, that is-most often mentioned in the media and in communication between people. Carbohydrate metabolism will be more convenient to consider in a “bundle” with fat, since both exchanges are mainly controlled by the same hormones. Moreover, these hormones and act similarly-those that increase the level of glucose in the blood, at the same time contribute to the saturation of blood fats, but the well-known insulin reduces the levels of glucose and fat in the blood.
An indicator of the level of intensity of carbohydrate metabolism is the concentration of glucose in the blood, and a similar indicator for fat metabolism is the concentration of free (or scientifically – unesterified) fatty acids.
Both parameters depend on the ratio of decay rates and synthesis of carbohydrates and fats. With carbohydrates, our body “deals” faster than with fats, that is, carbohydrate metabolism occurs faster than fat, in which anabolism is much slower than catabolism. As a result, the concentration of glucose in the blood is subject to much less fluctuations than the concentration of fatty acids. In a healthy body, the level of glucose in the blood can vary in the range of plus or minus 30%, the level of fatty acids increases and decreases significantly.
If you delve into the intricacies of the exchange of fats and carbohydrates and compare both energy reserves – glucose and fats, it begs the question of why fats are needed at all, as a form of energy reserve. Glucose splits easier, glycogen (animal equivalent of starch) is synthesized easier… why would the body store glycogen? Why complicate?
But you have probably learned (if you have read so far) that whenever the question arises “Why complicate?”, something remains outside attention, some important circumstance is not taken into account.
So what are the benefits of fats as “biological batteries”?
First, fats are a more compact form of energy storage than carbohydrates. Splitting one gram of fat gives twice as much energy as splitting one gram of carbohydrates. Agree that twice – this is a very significant difference. Especially considering that all this stock we constantly have to carry on ourselves. But you have to pay for everything and the increased capacity of the fat battery is no exception to this rule. The splitting of fats is a rather complex process, it certainly requires oxygen (and when splitting glucose, you can do without it) and some “starting” energy needed to start it. Where does the body get this energy? Breaking down glucose! We can say that fats burn in a carbohydrate flame (oxidation, that is, splitting with oxygen, is nothing but slow combustion).
Secondly, fatty acids, unlike glucose, easily penetrate through cell membranes without needing conductors, and are just as easily incorporated into cellular metabolic processes. Glucose the insulin has to literally “handle” to the cell.
The third circumstance follows from the second – in the body there are cells that do not use glucose as a source of energy. For example-actively working myocardial cells (heart muscle), which have no time to “exchange for trifles”, messing with glucose.
The breakdown of fats in our body (and hence the increase in the concentration of fatty acids in the blood) stimulates many hormones – glucagon, somatotropin, adrenocorticotropic hormone, glucocorticoids, adrenaline, noradrenaline, dopamine, serotonin, thyroid hormones, as well as lipotropin, a hormone of protein nature, produced by the pituitary gland [27].
If you think that the synthesis of fats (and lowering the concentration of fatty acids in the blood) oversees an equally representative group of top managers, you are greatly mistaken. Synthesis of fats involved insulin and, to a much lesser extent, estrogens, showing this action only in the body in women.
Stimulation of fat synthesis by insulin is carried out by increasing the absorption and absorption of glucose by fat cells. At the same time, insulin inhibits the breakdown of fats.
Exactly the same situation with carbohydrates. The above-mentioned group of top managers stimulates the breakdown of carbohydrates, increasing the concentration of glucose in the blood, and insulin, which promotes the absorption of glucose by cells, lowers its concentration.
Since carbohydrate and fat metabolism are controlled by the same hormones, severe endocrine disease – diabetes, is a violation of not only carbohydrate, but also fat metabolism.
If you ask-what foods should be limited in the diet of diabetics, and even completely excluded from it? – the vast majority will answer: “Sugar and sweets.” Yes, in fact, it is – the use of sugar and sugar-containing products diabetics are recommended to sharply limit up to complete exclusion from the diet. But, in addition, just as strongly and zealously should limit the use of fats. Doctors joke: “in diabetes it is better to afford to eat a sandwich with jam than with lard.” This joke is all true.
The breakdown of fats in diabetes mellitus is accelerated, because the body, being unable to absorb glucose, completely switches to obtaining energy from fats. It would seem that diabetics do not need to limit fats, but on the contrary – to increase their share in the diet. But the fact is that diabetes interferes with the normal metabolism of fatty acids in the blood build up so-called “ketone bodies” (acetone and its derivatives) that poison the body. Simply put, fats with diabetes into the body of poisons, so their use is severely restricted. Want to know more about the metabolism of fats in diabetes can type in search engine “diabetic ketoacidosis”, and we with carbohydrate and fat metabolism end and turn to protein metabolism.
“Bah, the same faces again! some readers will exclaim.
Yes-the same. New and take nowhere.
Here is a list of the main hormones that regulate protein metabolism:
- Somatotropin;
- Sex hormones;
- Thyroid hormones;
- Glucocorticoid;
- Insulin;
- Glucagon;
- Adrenaline and his team as norepinephrine with dopamine;
- Somatostatin.
Proteins in our body are synthesized everywhere and everywhere, so hormones that stimulate protein synthesis, we will consider not together, but separately.
Somatotropin stimulates protein synthesis both in the internal organs and in the musculoskeletal system-skeletal muscles, bones and cartilage, as well as in the immune system. Mechanism-acceleration of amino acid assimilation by cells. The faster amino acids are absorbed, the faster protein molecules “gather” from them.
On action on carbohydrate and fat metabolism somatotropin is an insulin antagonist, but on protein metabolism, both of these hormones work together. Insulin also stimulates protein synthesis. The only difference is in the sources of energy supply. Somatotropin uses for protein synthesis the energy obtained by splitting (oxidation) of fats, and insulin – glucose, and not “internal”, stored in the form of glycogen, and “external”, coming from food. Therefore, “pitching”, in addition to protein food, also “lean” on carbohydrate.
Unlike somatotropin, insulin increases the synthesis of proteins in several ways: stimulates the formation and functioning of ribosomes (cellular organelles responsible for protein synthesis from amino acids according to the given matrix); stimulates the synthesis of DNA and RNA, facilitates the passage of amino acids across cell membranes, depresses the “recycling” of amino acids into glucose by the liver cells that the body produces to supply energy (from glucose is then converted into glycogen). And insulin inhibits the breakdown of proteins, especially in skeletal muscle.
Insulin antagonist glucagon behaves in the opposite way. It interferes with the flow of amino acids into cells and the synthesis of proteins from them, and also stimulates the breakdown of proteins, and also first of all – in skeletal muscle. Glucagon also stimulates the” processing ” of amino acids into glucose by liver cells.
Glucocorticoids (mainly – well-known cortisol) inhibit protein synthesis and stimulate its decay and” processing ” into glucose in the immune system and in General all internal organs, except the liver, where glucocorticoids, on the contrary, stimulate the synthesis of a number of proteins. This is an interesting feature. But if we take in General, the breakdown of proteins glucocorticoids contribute much more than synthesis.
Male sex hormones androgens, acting with the help of somatotropin, promote protein synthesis in skeletal muscles, bones, male genitals and skin. They practically do not affect protein metabolism in the liver.
Female sex hormones estrogens stimulate protein synthesis in the female genital organs, mammary glands, as well as in the bones, but the skeletal muscles have no effect.
Thyroid hormones affect protein metabolism in almost the entire body, and they can stimulate both protein synthesis and their breakdown, depending on their concentration in the blood. In small quantities, thyroid hormones stimulate protein synthesis, and in elevated – decay. We will not go into the complex mechanism of their action for two reasons. First, the explanation of this mechanism will stretch over a whole Chapter, and, secondly, to understand this Chapter will require a fairly deep knowledge of biochemistry and physiology.
Adrenaline, norepinephrine and dopamine contribute to the breakdown of proteins in skeletal muscle and the use of amino acids derived from this process, liver cells for “processing” into glucose.
Hypothalamus hormone somatostatin, also produced in the Islands of Langerhans of the pancreas, inhibits protein synthesis throughout the body, but this is limited and does not stimulate the breakdown of proteins.
Summary
Metabolism and energy, which is scientifically called “metabolism”, consists of two interrelated processes: plastic metabolism or “assimilation”, the essence of which is the synthesis of organic substances in the body using external sources of energy (food) and energy metabolism or “dissimilation” – the process of disintegration of organic substances with the release of the desired body energy. Plastic also referred to as “anabolism” and energy as “catabolism”.
Metabolism can be divided into three parts by substances involved in the processes – protein, carbohydrate, fat.
The breakdown of fats and carbohydrates in our body stimulates glucagon, somatotropin, adrenocorticotropic hormone, glucocorticoids, adrenaline, noradrenaline, dopamine, serotonin, thyroid hormones, as well as lipotropin, a hormone of protein nature, produced by the pituitary gland.
Synthesis of fats stimulates insulin and, to a lesser extent, estrogens. Insulin also contributes to the absorption of glucose by the cells of the body, this is its main function.
Protein synthesis is stimulated by somatotropin, sex hormones, insulin, and inhibit glucagon, glucocorticoids (cortisol), adrenaline, noradrenaline, dopamine and hypothalamus hormone somatostatin. Thyroid hormones affect protein metabolism in two ways, depending on their concentration in the blood – in small quantities, thyroid hormones stimulate protein synthesis, and in elevated – decay.