“Hormones-engineers” are hormones that regulate metabolism, metabolism and energy in our body (for simplicity, they often say “metabolism” without mentioning energy).
To begin with – a bit of biology and chemistry.
Metabolism and energy consists of two interrelated processes: plastic metabolism (or assimilation), the essence of which is the synthesis of organic substances in the body using external energy sources (sunlight in plants or food in animals), and energy metabolism (or dissimilation), which is a process of decay of organic substances with the release of energy needed by the body.
Too hard? It is possible to tell and it is simpler – from food our organism receives energy which uses for development of the substances necessary to it.
In the body are constantly processes of synthesis and decay.
Hormones take part in the regulation of these processes.
The foods we eat are made up of proteins, fats, and carbohydrates.
What are proteins, fats and carbohydrates from a chemical point of view?
Proteins are high-molecular substances consisting of amino acids. “High molecular weight” means that the protein molecule is huge, that it contains a large number of atoms. There is no clear boundary, that is, the exact number of atoms from which a substance is considered to be high molecular weight. But in any case, the account of atoms in molecules of high-molecular substances goes to hundreds or thousands.
What is amino acid? This compounds the molecules contain both carboxyl (-COOH) and amine (-NH2) group.
Amino acids, which are part of the proteins, “only” 20, but this number provides a great many combinations, so that two identical proteins in nature does not exist. Some amino acids our body can produce, and others – no. Non-produced amino acids are called “essential”. We get them only with food.
Proteins in the body break down into amino acids, which are used to produce other proteins needed by the body. “Extra” amino acids, that is, those that have not been used in the synthesis processes, break down to water, carbon dioxide and other end products of metabolism or turn into glucose, which is always necessary for the body. If the body does not need glucose (i.e. energy) at a given moment, it can be stored in the liver or in skeletal muscles in the form of glycogen.
It is important to understand the following – the molecules of substances are something like a battery. Chemical bonds, that is, bonds between atoms in molecules, are formed with the absorption of energy, and are broken – with the release. Why reactions of formation of complex substances from simpler in a test tube often take place only when heated to certain temperatures or (less often) – in the light? Because thermal or light energy is needed to form new chemical bonds.
As already mentioned above, the breakdown of 1 gram of protein to the final product is 17.6 kJ of energy. But proteins are used by our body primarily as a source of “building materials”, that is, as a source of amino acids necessary for the synthesis of our own proteins. As a “fuel”, that is – to obtain energy, only those amino acids are used that the body does not need at the moment. Put amino acids for the future, our body is not able to.
In the case of severe exhaustion, when the fat reserves are completely exhausted, the body begins to “throw in the furnace” proteins, extracting from them the necessary energy for life. But we must understand that this happens only in a pathological (painful) state. In the normal state, the body does not use its own proteins to extract energy. Figuratively speaking, “heat the stove” proteins – it’s like to heat it with banknotes. Again – all the proteins in the body are “in business”, are part of a particular structure, are involved in a particular process. If proteins are withdrawn for energy, then those structures or processes in which they participate suffer. An example is the dystrophy of skeletal muscles in exhaustion caused by long-term chronic malnutrition.
We’re done with the squirrels.
Go to fats, our Main Keepers of the Energy in the decay of 1 gram of which this energy is allocated as much of 38.9 kJ!
Everyone knows that fats are a high-calorie product, but few people understand how high the calorie bar of fats is. For example, the caloric content of 100 grams of fat is almost 800 calories, and the caloric content of 100 grams of butter – about 720 calories!
By the way, during a quiet walk the body spends from 150 to 200 calories. Slimming people often allow themselves to eat something forbidden, high-calorie, consoling themselves with the fact that they “cover sin” with increased physical activity. So here is, keep in mind, that for neutralize one (one!) sandwich with bacon “medium” size (about 40 grams of fat) will have to walk a half to two hours.
It was an introduction, giving an idea of how much energy fats store. And now let’s get acquainted with fats closer.
Fats or triglycerides are substances consisting of molecules of carboxylic acids and triatomic glycerin alcohol (hence the “tri – glycerides”). In fact, fats do not consist of molecules, but of residues of carboxylic acid molecules and triatomic glycerin alcohol, just as proteins consist of amino acid residues, because when “combining”, that is, the formation of a more complex substance, the original molecules lose some atoms and with the help of released bonds bind together. But we do not need to go into such difficulties, so we say – “consisting of molecules.”
One fat molecule is formed by one glycerin molecule and three carboxylic acid molecules. Carboxylic acids are substances whose molecules contain one or more carboxyl groups (-COOH). That’s just for the record.
Fatty acids can be used by our body as a “building material” (among fatty acids as well as among amino acids, there are essential). And fats are “fuel”, a source of energy for the body. In addition, with a lack of water, fats can serve as its source – with the decomposition of 1 gram of fat, 1.1 ml of water is formed. Our body is able to store energy in the form of fat and glycogen, but glycogen plays a minor role in this case. An interesting fact – fat stores postpone not only the body as a whole, but also individual cells, not related to fat, which in the cytoplasm (semi-fluid internal environment cells) are droplets of fat – their “own”, “personal” energy reserve.
Please note that the fats obtained from food can not directly be deposited in the form of stocks. Dietary fats in the body are broken down, and those fats that are synthesized by the body are deposited in reserve.
The question may arise – why the body needs to spend time and resources first on the breakdown of dietary fats, and then on the synthesis of their own fats? Wouldn’t it be easier to put off what you get from food?
No, not easier!
First, fat to fat discord. Fats – a common name for a large group of substances, individual representatives of which are very different from each other in structure and properties. Adipose tissue cells are genetically “tuned to a certain wave”, that is, they are able to accumulate specific types of fat. Just so and not otherwise.
Secondly, fats can not circulate in the blood, it is dangerous for life. Fat is insoluble in water and, accordingly, in water-containing blood plasma, too. Molecules of homogeneous fats can be grouped together to form fat globules (droplets). Think of the “spots” of fat on the surface of the soup to imagine what large conglomerates can form fats. Sometimes all the fat in a bowl of soup, merges into one big spot. So, these balls of fat can clog blood vessels (scientifically called “fat embolism”) and deprive them of areas of blood supply. Violation of blood supply leads to tissue damage. If you suffer from such vital organs as the brain, heart or lungs, then it can end not just a disease, but a fatal outcome. Fortunately, fats are broken down in the gastrointestinal tract into molecules of glycerol and fatty acids, which are absorbed into the bloodstream and can not harm the body.
The main source of energy in our body are carbohydrates – substances containing carbonyl group (-C=O) and several hydroxyl groups (-OH). Low molecular weight carbohydrates are called “sugars”.
Not confuse the main source of energy with the main form of its the reservoir! By “source” means food. Carbohydrates are the main source because their share in the daily diet is twice the combined share of proteins and carbohydrates. The ratio of proteins, fats and carbohydrates in the diet of a healthy adult is 1:1:4.
Necessary clarification – what we used to call “sugar” in everyday life, is actually sucrose, disaccharide (double sugar) from the group of oligosaccharides (low molecular weight sugars), consisting of the remains of two monosaccharides (single sugars): glucose and fructose.
Glucose or grape sugar is the most common source of energy in living organisms. Glucose can exist in two forms: open and cyclic. In glucose solution, these forms are in equilibrium with each other. In the solid state, glucose has a cyclic structure.
In the blood we have glucose, not some other substance from the group of sugars. Therefore, it is wrong, that is – illiterate to talk about “the level of sugar in the blood.” We need to talk about the level of glucose! Blood delivers glucose to the cells of our body, and in the cells there is a process of decomposition of glucose for energy.
Glucose forms three high-molecular substances – starch and cellulose, characteristic of plants, as well as glycogen, which serves as the main reserve carbohydrate (that is, the main form of glucose storage) in animals. Most glycogen is found in the liver and muscles.
Starch in plants serves to store glucose, and cellulose forms a rigid frame that replaces the skeleton of plants. Despite the fact that starch and cellulose are made from the same monomer – glucose, these substances vary greatly in their properties and the main difference is that we can eat starch, and cellulose – no, because our body is not able to break down the cellulose molecules. Only some species of animals that are able to eat wood (for example – in termites) or grass (all ruminants), the body has enzymes that can decompose cellulose into glucose molecules.
Carbohydrates that we eat are glycogen, starch and sugar – sucrose, glucose, fructose, galactose, etc. Ultimately, in the process of metabolism, all complex carbohydrates are broken down to monosaccharides, mainly – to glucose. Fructose, galactose and other monosaccharides (in the company of glucose) can be used by the body for the synthesis of other substances. Those monosaccharides that do not serve as a “building material” are converted into liver or glucose, or in intermediate products of its exchange, which are then decomposed to carbon dioxide and water with the release of energy.
Unused glucose the body normally does not output, and puts in reserve in the form of glycogen or fat. Glycogen reserves are limited, that is, it is impossible to accumulate too much, but fat reserves can grow indefinitely. Conditionally – to infinity. In fact, at some point, fat reserves become incompatible with the normal functioning of the body and kill it.
Glycogen is produced in the liver and skeletal muscles, and fat reserves are formed – at the place of its deposition. Blood fat stores to the place of storage is not transportorul. Where the reserves are formed, where they are stored.
The introductory part is almost finished. In order for the picture to be complete, it remains to say how much glucose is normally contained in the blood of an adult, and explain what the glycemic index.
In an adult, the blood sugar level in the normal fasting ranges from 3.2 mmol/l to 5.5 mmol/l.
The glycemic index reflects the rate at which carbohydrates contained in food are absorbed by the body and increase blood glucose levels. Example – if we eat 50 grams of glucose and 50 grams of white bread crumb or, say, potatoes (that is – starch), in the first case, the level of glucose in the blood will begin to increase literally immediately, and in the second – not immediately, because the starch must first be processed. Therefore, the glycemic index of white bread from flour of the highest grade is on average 80 units, and the glycemic index of glucose – 100 units.
Introduction to hormone engineers we will start with insulin, a protein hormone of the pancreas (remember the islets of Langerhans) that regulates metabolism in the body.
Pay attention – insulin regulates metabolism, not only glucose metabolism! Glucose is the main, but not the only “object” of insulin.
About insulin, probably heard everything. It is the most studied and most popular of hormones. Even completely far from medicine people will say: “and, we know-we know, with a lack of insulin develops diabetes.” Yes, that’s right – if the body is not enough insulin, it develops a disease called diabetes mellitus type one.
Due to the lack of insulin, which helps cells absorb glucose contained in the blood, cells completely cease to absorb glucose or do it with much less enthusiasm. As a result, the level of glucose in the blood increases. The body tries to fight this increase by excreting glucose in the urine. Normally, there is no glucose in the urine. Glucose metabolism disorder triggers a chain of metabolic (metabolic) disorders in the body. Think about the Domino effect, when one Domino falling knocks the next one in the chain, and so continues until, until all the dominoes will not fall. In violation of glucose metabolism, one metabolic disorder follows another until the entire metabolism in the body is broken down. At the same time with carbohydrate metabolism also disturbed protein metabolism and fat metabolism, which also involved insulin.
With diabetes of the first type, everything is clear at once, that is all very logical. Lack of insulin leads to the development of the disease.
And will you believe if you are told that diabetes can develop and with normal insulin content in the blood, in the development of its Islands of Langerhans in sufficient quantities?
Most likely, will not believe, because in the mass consciousness diabetes are closely linked (one might even say – bound by one chain) with inadequate secretion of insulin. Little insulin – diabetes, insulin was normal – no diabetes, something like that.
Then let’s take a moment away from hormones and diseases and consider this situation – can the car not start in the presence of fuel in the tank? Of course it can! Fuel for the car is necessary, but its presence is only one of the conditions of this process. In order for the car to start, you need a coordinated work of several nodes.
Approximately the same is the case with glucose metabolism, and in General with all processes that are regulated by hormones. It is not enough to have the required amount of hormone in the body, it is also necessary that this hormone is perceived by cell receptors, so that the cells would be sensitive to it. Otherwise, the hormone will be “idle”, will circulate through the body unclaimed.
Let’s see why there is insensitivity (scientifically called “resistance”) to a particular hormone?
Please note that we are not talking about the lack of hormone production, but about insensitivity to it, a situation where the hormone is produced in sufficient quantities, but does not have the desired effect on the body.
There can be four reasons.
First, the emergence of resistance can lead to a congenital defect in the structure of the hormone molecule, resulting from mutation – changes in hereditary information that is stored in the genes. Hereditary information is encoded as a sequence of fragments in the DNA molecule (deoxyribonucleic acid). Two fragments have changed places – here’s a mutation, as a result of which instead of “normal” insulin will be produced “abnormal”, very similar, but not like this.
Secondly, there may be some factor in the blood that interferes with the interaction of hormone molecules with receptors, a factor that binds to hormone molecules and thus makes them unable to fulfill their purpose, that is – neutralizes them. For example – toxic products that accumulate in the blood in chronic renal failure, when the kidneys do not have time to remove all unnecessary from the body with urine, can bind to insulin or somatotropin molecules.
Often as a neutralizing factor are antibodies – proteins produced by the immune system in response to the penetration of foreign agents (antigens) into the body. As a result of some failure of the immune system takes “his” produced in the body hormone for an alien agent and begins to produce antibodies against it neutralizing. As a result, the hormone is released into the blood, but does not reach the receptors or comes in insufficient quantities, because on the way it is “intercepted” antibodies. If the endocrine system will increase hormone production, the immune response will increase the production of antibodies – there is a kind of vicious circle, which without outside intervention (ie – without medical care) can not be broken. With the same success and the same pattern of antibodies can block receptors, communicating with them instead of hormone molecules, but this reason already belongs to the next, the third group of causes.
Third, the interaction of hormone molecules with receptors may be disturbed. For example, if the receptors have changed as a result of mutation or lost their sensitivity, that is – the ability to create a specific signal for the cell after interaction with the hormone molecule. Or if (as just described) instead of the hormone to the receptor is contacted is another matter.
Fourth, and with the hormone molecules and receptors may be all right, they will interact properly and the result will be the right signal, but this signal does not reach its destination, to the cellular structure, which it was intended, due to a violation of the signal inside the cell. The Telegraph operator sits at the serviceable device and diligently transmits the message, but the trouble is – somewhere the wire is broken and the message does not reach its destination.
What will you do the body with insulin resistance (the so-called reduction reaction of the receptors for insulin)? If you remember that any organism is a self-regulating system that seeks to eliminate all the problems, you will answer that in this case the production of insulin in the body will increase. But nevertheless, will develop diabetes – diabetes mellitus type II, diabetes, in which insulin is produced even more than you need.
Insulin resistance can be not only pathological (that is – painful), but also physiological, arising in a healthy body during puberty or pregnancy.
During pregnancy, the mother’s blood must have a high (increased) concentration of glucose in order to ensure the transport of glucose to the fetus through diffusion – the process of spontaneous alignment of the concentration of the substance in two solutions separated by a semi-waterproof membrane. From the mother’s blood, where glucose is greater, molecules pass into the fetal blood, where glucose is less.
In the puberty period, as you already know, the body produces a lot of somatotropin, which in its action on carbohydrate metabolism is an insulin antagonist, because it prevents the absorption of glucose by fat, liver and muscle cells. In this case, the resistance of cells to insulin can be considered as a “side effect” of somatotropin, which is eliminated by increasing the production of insulin in the pancreas.
So, when there is insufficient production of insulin developing diabetes of the first type, and in violation of the sensitivity of cells to insulin – diabetes mellitus of the second type. Diabetes mellitus type the first type is called insulin-dependent, and diabetes mellitus type the second type – insulin-independent.
Increased absorption of glucose by muscle and fat cells is expressed in the fact that insulin increases the permeability of cell membranes to glucose and activates enzymes involved in its breakdown. Glucose enters the cell not by diffusion through the pores (for this its molecules are too large), and through special protein channels, the number of which increases insulin.
Muscle and fat tissues are most sensitive to the action of insulin and are therefore called “insulin-dependent tissues”. On other tissues insulin acts poorly.
In addition, insulin stimulates enzymes involved in the formation of glycogen in the liver and muscles – “animal starch”, a form of glucose reserve. At the same time, insulin inhibits the activity of enzymes that break down glycogen, that is, this hormone only works to create reserves of glucose on the principle of “the more the better.” It is known that stocks (as well as money) are not superfluous.
Insulin stimulates the production of fatty acids in the body, that is – promotes the formation of fat and simultaneously inhibits the enzyme lipase, which breaks down fat. Insulin also helps to convert glucose into fat. But do not think that this insulin harms our body, promotes obesity. Fat formation is part of normal metabolism and energy. Fats are part of a number of cellular structures, primarily – in the cell membranes. Fats are necessary for the body for normal life. And obesity is not caused by insulin, but by overeating with hypodynamia.
In a similar way (that is – by creating additional protein channels) insulin increases the permeability of cell membranes to amino acids, potassium ions, magnesium ions and phosphate ions (PO43-).
Insulin stimulates the formation of proteins.
Insulin has another function, which no one knows about except doctors and biologists, despite the fact that this function is as important for the body as the regulation of glucose metabolism. And perhaps even more important – insulin stimulates DNA replication – the process of synthesis of a new DNA molecule based on the parent molecule. This is done to ensure that the daughter cell, formed by cell division, would have inherited from the mother a complete set of DNA. There will be no replication – there will be no cell division, and without this division the body can not exist.
Probably, some of the readers will now be surprised and say: “This growing organism can not exist without cell division, and an adult – quite, except that the hair and nails will stop growing.”
No! And in the adult organism, the growth of which has already stopped, there is a constant cell division. Cells are constantly self-renewing. The life of different cells is different. For example, cells of the mucous membrane of the small intestine (never say “small intestine”, this is wrong) live on average only 36 hours, and red blood cells on their background look real “long-livers”, because they live about four months. Some cells of the immune system live for years, and nerve cells can live throughout the life of the body.
Cells divide constantly, and in this them helps insulin.
Try to solve one riddle that is not directly related to the topic of our conversation, but related to insulin. The question is: why is there no insulin in pills or capsules? Why do many diabetics have to inject themselves with insulin several times a day? Science has reached incredible heights, the pharmaceutical industry works wonders, but insulin has to be injected only. Soon it will be a hundred years of insulin use for medicinal purposes, and who is now there, that is – you have to wield a syringe. But the tablet is not only convenience, but also safety, because when injected there is always a risk of infection.
Tip – it’s not that insulin should be injected directly into the blood and nothing else. Moreover, insulin injections are made intravenously, and subcutaneously. It’s about insulin.…
The answer to this question will be given at the end of the Chapter before the summary.
All hormones are important, the lack of any hormone leads to disruption of normal functioning of the body, but insulin can be called “the most important of the important”, because it is the Main Manager of Energy resources in our body.
And who manages the Chief energy Manager? In other words – what factors control insulin production?
The main stimulant of insulin production is to increase the level of glucose in the blood. It’s the most powerful stimulant. In addition to glucose, insulin production stimulates an increase in the level of potassium, calcium, free fatty acids and amino acids in the blood. From hormones contribute to the formation of insulin adrenocorticotropic hormone, estrogens and glucagon, also produced in the islets of Langerhans of the pancreas.
Like insulin, glucagon is a protein.
Like insulin, glucagon regulates glucose metabolism, but glucagon is an insulin antagonist. If insulin lowers the level of glucose in the blood, promoting its absorption by cells and stimulating the synthesis of glycogen in the liver, glucagon stimulates the breakdown of glycogen in the liver, which increases the level of glucose in the blood.
An interesting feature – glycogen stored in the muscles, glucagon has no effect, because the muscles are not sensitive to glucagon receptors.
Glucagon also stimulates the production of glucose by liver cells. Note – we are talking about the synthesis of glucose from simpler substances, not the release of it as a result of the disintegration of glycogen.
Glucagon stimulates insulin production and lowers the activity of the enzyme insulin, which destroys insulin. It can be said that glucagon is simply obliged to do so, is obliged to promote an increase in the level of insulin in the blood, because it (glucagon) increases the level of glucose. Someone (that is, insulin) has to promote the use of this glucose!
Glucagon stimulates the heart muscle, resulting in increased heart rate and strength and increased blood pressure (if the pump starts to work more intensively, the pressure in the system decreases). However, in large doses, glucagon lowers blood pressure, because it relaxes the muscles of the vascular walls, as well as the muscles of internal organs, in particular – the intestine.
And glucagon is a stress hormone. In the Chapter on these hormones, glucagon was not mentioned intentionally, because it is more convenient to talk about this hormone “in conjunction” with insulin. So, in stressful situations, glucagon increases the permeability of skeletal muscle cell membranes to glucose and a number of other “energy carriers” – free fatty acids and keto acids.  Increased permeability, as in the case of insulin, occurs by increasing the number of protein channels in the membranes.
Note that the protein channel is not a channel in the literal sense of the word, that is, is not a narrow extended hollow space in the thickness of the cell membrane. No, the channel is a protein molecule that connects (captures) with the molecule of the transported substance at the outer surface of the membrane and transfers it to the inner surface (that is – inside the cell), where the compound “protein – transported substance” is broken.
Stimulation of cardiac activity is also important during stressful situations, when you need to either beat or run away.
And the third, last, “stressful” action – glucagon stimulates the production of adrenaline, norepinephrine and dopamine in the adrenal glands, as well as increases the sensitivity of body cells to these substances.
And now let’s remember well-known to us (the truth – on the other hand) cortisol, which among other things is a regulator of metabolism in our body.
Cortisol stimulates the breakdown of fats, but at the same time increases the fat supply indirectly, because it increases the level of glucose in the blood, stimulating its production by liver cells. High blood glucose stimulates secretion of insulin by the islets of Langerhans. And insulin, as mentioned above, stimulates the production of fatty acids, inhibits the enzyme lipase, which breaks down fat and promotes the conversion of glucose into fat. Thus, cortisol increases fat supply with insulin.
Cortisol’s ability to increase appetite is also important for fat deposition. It is noteworthy that under the action of cortisol there is a characteristic redistribution of fat, which is mainly deposited in the head, neck, face and trunk, but practically not deposited on the lower extremities – there is obesity of the upper body.
Hormones that affect metabolism in everyday life are incorrectly called “hormones that affect weight.” Why wrong? Yes, because hormones do not regulate weight as such, but the metabolism and energy. Weight change is the result of a violation of the energy balance in the body, but is not a “merit” of a hormone, for example – cortisol. Yes, cortisol increases appetite and contributes to the deposition of fat reserves, but if a person does not overeat, then cortisol will have nothing to put off in reserve, even with an increased level of hormone in the body. Our weight is controlled by one simple “universal” principle. If the body gets more energy from food than it needs, it will put off excess energy in the form of fat, that is, the weight will grow. If the body receives less energy from food than it needs, it will receive the missing energy by oxidation (“burning”) of stored fats and the weight will decrease. If the body gets with food as much energy as it needs, the weight does not change. Phrases like: “I have a metabolic disorder, so I put on weight, despite the fact that I eat little” are essentially a lie. Yes, metabolic disorders can lead to obesity, but in any case, you need a material for the formation of fats that are deposited in reserve, you need certain amounts of certain substances and energy. No material – no fat. Something like that, and nothing else.
And since we are talking about weight, here’s a question that students like to ask on the exam in endocrinology: “Why is the characteristic feature of type 1 diabetes is painful thinness, and with type 2 diabetes, obesity is very common?”.
Well, with diabetes of the first type, i.e., with insulin-dependent diabetes, all clear at a glance. Lack of insulin disrupts the absorption of glucose in the body, that is – the body experiences malnutrition, “burns” fat stock and nothing more for the future does not postpone. But seems to be in diabetes of the second type, there should be something similar, but for some reason this is not happening and instead the thinness obesity develops…
The question was insidious, with a trick. The students in the exam and such usually ask. The fact that diabetes type II diabetes obesity is not a consequence of the disease, and the cause of its occurrence. Obesity is the main, most important risk factor for the development of type II diabetes. With each extra kilogram, the risk of developing type 2 diabetes increases by about 4.5 %! The reason is that for a number of reasons, which we will not disassemble, so as not to get stuck in them for a long time, obesity increases insulin resistance. (The, who wants to delve into this subject, can to garner in search engine “Obesity and diabetes mellitus type the second type” and to study found information.) More precisely, insulin resistance increases adipose tissue. Do not think that fat cells serve only as a depot of energy. No, these cells produce a lot of biologically active substances, some of them contribute to the development of insulin resistance. In some cases, with normalization of weight signs of diabetes of the second type disappear.
Interesting relationship growth hormone somatotropin and insulin. In the regulation of carbohydrate metabolism, somatotropin acts as an insulin antagonist, since it causes a marked increase in the level of glucose in the blood. Irreconcilable hostility is evident, and no peace is possible in this case. But in the regulation of protein metabolism: somatotropin insulin participate together for the manifestation of stimulating action of growth hormone on protein synthesis requires the presence of insulin. Here such turn out “pies” – there we are at war, and here we are friends.
Thyroid hormone triiodothyronine (thyroxine) is called “universal hormone” because it affects almost all cells of our body, and not some individual target cells. Thyroxine has the ability to penetrate cell membranes and stimulate the production of proteins in the cell.
Thyroxine in the cell is a high confidence. It is allowed in the Holy of holies – to stimulate the synthesis of RNA (ribonucleic acid).
In the cell there are spherical formations that do not have their membrane, which are called ribosomes. Ribosomes perform a very important function – synthesize proteins from amino acids, according to the information recorded in the molecule of ribonucleic acid. RNA molecules are formed by the matrix – part of the DNA molecule. Simply put, the DNA molecule copies its individual fragments in a somewhat simplified form so that these fragments would control the synthesis of proteins. The number of ribosomes in a cell can reach tens of millions, and the DNA molecule is only one and it does not break apart. So we have to synthesize RNA molecules.
Protein production is the basis of cellular activity.
Cells divide, renew their structures, produce some substances, receive energy for vital activity by means of chemical reactions, derive final products of exchange… And so on. And all these processes occur with the participation of certain proteins. No wonder that people are called “protein body”, and our civilization “protein life form” (although it is more correct to talk about “carbon” or “hydrocarbon” form).
Triiodothyronine stimulates both the process and the synthesis of RNA molecules required for this process. Triiodothyronine does a great job! I honor him for it and praise, or, as they say now – respect and uvazhuha!
But that’s not all. By promoting protein synthesis in ribosomes, triiodothyronine stimulates oxidative processes in the cell. Oxidation processes are called chemical reactions, which result in the addition of oxygen atoms to the atoms of other elements. To say it simply – triiodothyronine promotes decomposition of proteins, fats and carbohydrates that occurs with the participation of oxygen. In everyday life, this process is called “burning” and in General it is called correctly, because combustion is a fast-flowing oxidation reaction. Fast flowing! Due to this speed, a significant amount of heat is released during combustion in a short time and the process is accompanied by a bright glow – flame. With a slow flow of the reaction, the glow is not observed, and the heat is released not so intensively, but is released, since the transformation of complex substances into simple ones is always accompanied by a rupture of bonds and the release of energy.
And now let’s think about where the excess energy released during the breaks of chemical bonds disappears. With the energy contained in the chemical bonds of glucose, fatty acids and other substances, everything is clear – the body will process these substances into fats, thus preserving the energy reserve. But with the unnecessary energy that has already been released from chemical bonds as a result of intensive “burning” of substances, the body can not do anything. The excess energy is given to the surrounding space in the form of heat – the body temperature rises. An increase in body temperature is a characteristic sign of increased function (scientifically – hyperfunction) of the thyroid gland. Iron works “at high speed”, throwing into the blood a large number of hormones. Increases glucose consumption. In order to make up for the lack of glucose in the liver and muscles is enhanced glycogen breakdown. Intensely oxidized fats, deposited. And so on… And as a result, the body begins to produce heat more intensively, but there is no benefit to it.
In infectious diseases, there is a benefit from an increase in body temperature – pathogens die, for which temperatures from 38 °C and above are unfavorable. And with hyperfunction of the thyroid gland, the body simply heats the surrounding space more, nothing more. To catch this “leaking through fingers” heat we are not able.
There is an opinion that hot soup is more caloric than cold, because heat is calories, that is, a kind of energy. Yes – calories, but we can not absorb them, because in our body there are no specific “heat traps” that convert thermal energy (infrared radiation) into energy of chemical bonds. Similarly, we are unable to absorb the energy of solar radiation. So for us, the caloric content of the soup is determined by its composition, but in any case not by its temperature.
Some readers may object, saying that temperature can still affect the caloric content of food. When we eat ice cream, the body has to spend some calories heating cold food to body temperature. Theoretically – Yes, but practically no, because the weight of the eaten ice cream is many times less than the weight of the body and the loss of calories for heating it will be relatively small, so small that you can not take it into account. Lose weight, eating ice cream, will not work.
But you will lose weight by taking thyroid hormone medications! Lose weight without much stress, without intense exercise and without restrictions in the diet. A slight inconvenience in the form of increased temperature of the body can suffer, it is in fact nonsense.
It would seem that weight loss with the help of hormonal drugs is a wonderful solution. Especially given the fact that “thyroid” drugs are available and inexpensive. One hundred tablets of thyroxine cost less than two hundred rubles. Yes, of course, all hormonal drugs are prescription, but… Well, you know, with a strong desire to get a prescription is not difficult.
It would seem… Everyone knows how to act if something seems? That’s right. The following paragraph “takeplace” deliberately, in order to stand out. Read it a few times to remember for a lifetime.
ANY HORMONAL MEDICATION SHOULD BE TAKEN ONLY ON PRESCRIPTION AND ONLY FOR THE CORRECTION OF ANY EXISTING VIOLATIONS OF THE HORMONAL BALANCE BUT NOT FOR WEIGHT LOSS, MUSCLE BUILDING AND OTHER SUCH PURPOSES. THE EXCEPTION TO THIS RULE ARE THE ONLY BIRTH CONTROL HORMONAL TREATMENTS, BUT THEIR INTAKE SHOULD BE DISCUSSED WITH A DOCTOR.
First, our body is a self-regulating balanced system and to intervene in this self-regulation is possible only if something went wrong, that is – in the case of disease. If everything goes in a normal way, you can not interfere, the benefits will not be, only one harm. Acceleration of metabolism in fact is a VIOLATION of NORMAL METABOLISM, let alone let us call a spade a spade.
Secondly, the vast majority of hormones, as you have already seen, have several professions, are “responsible” not for one process that occurs in the body, but for many different processes. Perhaps only liberins and statins, which are produced in the hypothalamus, have one function – affect the production of certain hormones of the pituitary gland (remember somatoliberin, which stimulates the production of somatotropin). But it is possible with a high degree of confidence to assume that liberins with statins have several functions, but they are not yet open and have not been studied. Endocrinology is a young science. The same somatoliberin was first isolated from the hypothalamus in 1964, but its chemical structure could be established only in the mid-eighties.
As for thyroxine, widely used in narrow circles to reduce weight, the thyroxine-triiodothyronine in addition to accelerating metabolism, there are actions such as increased heart rate or thickening of the lining of the uterus in women.
With increasing heart rate increases the need for heart muscle oxygen. If the blood vessels that feed the heart muscle are narrowed, the blood supply may not have time to provide increased oxygen demand. Without getting the required, muscle cells die… there’s Probably no point in explaining what a myocardial infarction is?
Clever you to lose weight “no problem” (the quotation marks are not accidental), compromising the heart muscle? Scarcely.
Thickening of the uterine mucosa may cause pain in the lower abdomen or bleeding that is not associated with menstruation, and the menstrual-ovarian cycle may be disturbed . Do I need to reduce the weight of such a “bonus”? Also unlikely.
Thirdly, regular administration of the hormone from the outside suppresses its secretion, the feedback principle is triggered in the body, in which the result, that is, in our case – the level of hormone in the blood, controls its production.
Fourthly, if you do not change food and motor habits, that is – do not limit yourself in food and do not try to move more, then everything “burned” with the help of thyroxine will soon return to its places. But if you eat less and move more, you can safely lose weight without hormones.
All that has been said about weight loss with thyroxine, can be attributed to muscle building with the help of anabolic agents. There is no need to repeat. Better let’s see what is the impact on metabolism of male and female sex hormones. “Secondary”, that is – weakly acting, sex hormones, we will not pay attention, we will get acquainted only with the strongest, brightest representatives of both groups – testosterone and estradiol. Moreover, all male sex hormones imitate testosterone, acting the same as he, but weaker, and all female – estradiol.
Gallantly skipping the ladies forward, let’s start with estradiol.
Estradiol affects metabolism in bone cells. These cells are different, among them there are three types – osteoblasts, osteoclasts and osteocytes.
Osteoblasts are young bone cells that produce a solid intercellular substance and as the accumulation of this substance are as if immured in it. “Immured” adult cells are called osteocytes.
If someone creates bone, then someone has to destroy it, right? The destruction of bone tissue are the osteoclasts – huge (cellular scale) eaters.
Estradiol strongly inhibits osteoclasts – prevents their formation, reduces their activity, and even reduces their life expectancy. But to young osteoblasts estradiol refers differently – cherishes them and cherishes, promotes their formation, stimulates their activity, prolongs their life. Estradiol also stimulates the absorption of calcium from the small intestine into the blood, as well as the absorption of calcium by osteoblasts.
Simply put, estradiol promotes the formation of bone tissue and inhibits its decay. More estradiol – stronger bones are, the less estradiol the bones weaker. After 3-5 years after menopause, the production of female sex hormones practically stops, which leads to the development of osteoporosis, a disease characterized by a decrease in the density (increased fragility) of bones due to metabolic disorders in bone tissue.
Since we are talking about bone tissue, we will make a small digression and remember the parathyroid hormone produced by the parathyroid glands (it was mentioned in the course of an overview of the endocrine system), and the hormone calcitonin, produced by the thyroid gland.
The stimulus for the secretion of parathyroid hormone is a decrease in the level of calcium in the blood. It can be concluded that parathyroid hormone increases this level. It stimulates the development and activity of osteoclasts, thereby contributing to the destruction of bone tissue and the release of calcium into the blood. Along the way, parathyroid hormone stimulates calcium absorption in the intestine and its reverse absorption in the kidneys. That is, parathyroid hormone is an antagonist of estradiol on the action on bone tissue.
Calcitonin, a hormone of protein nature, is produced by special cells of the thyroid gland in response to an increase in the concentration of calcium in the extracellular fluid. This hormone suppresses the activity of osteoclasts, that is, suppresses the destruction of bone tissue, resulting in the outflow of calcium from the bones decreases.
Strengthening the bones, which is certainly good, estradiol stimulates the formation of fat and, accordingly, its deposition in reserve, which is not always good. But nothing can be done – female sex hormones are by definition supposed to provide the body with reserves “for a rainy day” in the same way as male sex hormones are supposed to stimulate the development of muscles. From a biological point of view, the main purpose of any organism is to produce offspring. A woman carries offspring, so her body needs energy reserves. The task of a man is to protect and produce food, so he needs developed muscles. In nature, everything is logical, and what seems illogical to us, we are still simply not able to explain.
In adipose tissue there are estrogen-sensitive receptors, stimulation of which leads to an increase in fat formation. Most of these receptors are found in the adipose tissue of the thighs and buttocks. Accordingly, fat is deposited there more than on the stomach, so that the female figure differs from the male greater width of the hips. After menopause, in the absence of estradiol and other female sex hormones, there is a relative redistribution of body fat. In the hips, they become less, and in the abdomen – more.
An interesting detail – the excess of carbohydrates and lack of fat in the diet can inhibit the production of estradiol so that it can reach the end of menstruation.
Estradiol has the ability to retain sodium in the body, increasing its reverse absorption in the kidneys, which leads to swelling, because with sodium and water is delayed. It is sodium and water retention caused by a high content of estradiol and other female sex hormones in the blood that causes physiological swelling of pregnant women. The reason is hormones, and not that the heart of a pregnant woman allegedly can not cope with the loads.
Estradiol has a pronounced anti-atherosclerotic effect, that is – prevents the deposition of cholesterol and other substances (fats and low-density lipoproteins ) on the inner surfaces of the vascular walls. This is achieved by reducing the concentration of cholesterol and his entire company in the blood. Therefore, women of reproductive age rarely develop atherosclerosis. (Let’s remember that cholesterol is the precursor of all steroid hormones, that is, they are synthesized from cholesterol, we have already talked about this.)
Testosterone, if you do not know, does almost nothing in the body. The use of a zero point, zero-tenths, and five hundredths of a second, i.e. quite a bit.
Not a typo. So it is. The fact is that the famous testosterone, like thyroxine, has almost zero biological activity. In order to gain power, that is to become biologically active, testosterone must turn into dihydrotestosterone. This process takes place directly “on the ground”, that is – in the bodies. If from a chemical point of view the difference between testosterone and dihydrotestosterone is small (you can see this by comparing the formulas of both substances), from a biological point of view, the difference is simply huge. Sluggish lazy-clumsy testosterone at the wave of a magic wand, which is called the enzyme 5-alpha-reductase, turns into a professional workaholic.
The main effect of testosterone on metabolism is manifested in its ability to stimulate protein production. Testosterone stimulates the production of proteins almost throughout the body, in all cells, but especially this action is expressed in the cells of the organs responsible for the development of sexual characteristics of the male body, both primary and secondary.
Penetrating into the cell, testosterone binds to the protein receptor, which is located in the cytoplasm. Then the complex “hormone receptor” penetrates into the cell nucleus, which stimulates the production of RNA matrix, which in the cell “stamped” proteins. DNA self-copying is also stimulated, which accelerates cell division. That is, testosterone does not just increase protein production, but stimulates cell division. It is logical – and what else to do with large amounts of proteins produced, how not to use them in the “construction” of new cells?
Here’s a question for your intelligence – in 1 mm3 of blood in men contains up to 5.5 million red blood cells, and women “only” up to 4.7 million. Why is this happening? What is the reason for this difference?
Of course, the fact that in the bodies of men contains more testosterone, stimulating cell division, including blood. Among other things, testosterone controls the formation of sperm in the testes (testicles). And their daily Matures about 100 million, that is – about 1000 per second! Amazing intensity, isn’t it? And as grow under the influence of testosterone… How muscles grow! Literally by leaps and bounds!
Warning – the use of testosterone for the acquisition of musculature is not worth it. You will lose much more than you gain. With health, until it there is, better not to joke, itself more expensive.
To a small extent, testosterone has the ability to increase the reverse absorption of sodium in the kidneys. But this ability of the hormone does not lead to edema, because it is expressed very weakly.
Let’s dispel one misconception associated with testosterone. Most readers should know the expression, almost – proverb: “The fact that every Professor was a student does not mean that every student will become a Professor.” Cause-and-effect relationships cannot be turned inside out. The fact that testosterone stimulates protein synthesis in the body does not mean that excess protein in the diet will stimulate testosterone production.
Like estradiol, testosterone stimulates the development of bone tissue, though not to such an extent as muscle development. And this stimulation is very interesting, if not to say – magically. In order to have an effect on bone tissue, testosterone first needs to turn into estradiol. (Comparing the above formulas of both substances, you will see that they are very similar to each other.) Conversion occurs in adipose tissue under the influence of an enzyme called aromatase.
Now look at the formulas of testosterone and estradiol molecules. As a result of the conversion of testosterone into estradiol in the molecule appears benzene ring (bottom left). That is, there is aromatization. Therefore, the enzyme is called aromatase, despite the absence of any smell. Love these chemists to confuse the issue, I tell you. They do not feed bread, only let me put a shadow on the fence, let in more of the fog.
By the way, all female sex hormones are formed from male. That is, androgens are biochemical precursors of estrogens. In the next Chapter, we will talk about the metamorphosis of sex hormones in more detail, and this Chapter is probably time to finish, otherwise it will grow into a whole book. Most importantly, that is – the main hormones that affect metabolism, we considered, along the way, talked about a lot of different things that are not directly related to metabolism, so it’s time to wrap up. And if something was not mentioned, it is not terrible. We end up having a light conversation about hormones at the level of friendly chatter, rather than writing a textbook on endocrinology or biochemistry.
In the next Chapter, we will talk about hormones-pimps, which form sexual differences and libido. You are already familiar with them, but so far they have appeared to you in a respectable perspective, so to speak. Strong bones, growth of muscles, and pushed to different madness and orgies. But the hour has struck and it’s time to tear off the mask, it’s time to give everyone their due…
ANSWER TO the QUESTION: Insulin is a protein that is digested in the gastrointestinal tract, is broken down into amino acids. Our body perceives ingested insulin not as a medicine, but as food. By the way, modern science has almost solved the problem of protecting insulin from digestion in the gastrointestinal tract. Invented a complex filler for tablets that protects insulin, though not all contained in insulin tablets, but only part of it, sufficient to provide a therapeutic effect. This insulin is absorbed into the blood in the colon, where the intensity of digestion is low, but the absorption is intense. But any problem has an economic aspect. Each tablet should contain a significant amount of insulin, which is laid with a large margin, taking into account the losses “in the way”, in the process of moving the tablet to the colon. “At”, that is, to the colon, despite the wonderful filler, comes a smaller part of the insulin contained in the tablet. Most of it gets lost on the way. And insulin is a very expensive drug and therefore tablets with high insulin content have a high cost, which will certainly affect the demand for the drug on the market. Few people will be able to afford to constantly buy such an expensive drug. So that problem insulin pills until that can be considered solved only theoretically.