What are peptides and what are they for? Human hormones may be peptides.

PROTEIN-PEPTIDE HORMONES- an extensive group of hormones produced by various endocrine glands, which are proteins or peptides in structure. The largest amount of protein-peptide hormones is secreted by the pituitary gland: oxytocin, vasopressin, alpha- and beta-melanocyte-stimulating hormones, adrenocorticotropic hormone (ACTH), lipotropic hormone, growth hormone, lactogenic, luteinizing, follicle-stimulating and thyroid-stimulating hormones. The pancreas produces yes hormones - insulin and glucagon, the parathyroid gland - parathyroid hormone and the thyroid gland - thyrocalcitonin. A large group of peptide hormones are secreted by the hypothalamus; they are called releasing hormones of the hypothalamus, as they stimulate the release of hormones from the anterior pituitary gland (from the English realease - I allocate).

According to the chemical structure, protein-peptide hormones are extremely diverse. Most of the protein-peptide hormones are simple peptides, the molecule of which consists of a single peptide chain containing a different number of amino acid residues, from 3 in the thyrotropin-releasing hormone of the hypothalamus to 198 in the lactogenic hormone. Oxytocin and vasopressin contain 9 each in their molecules, and melanocyte-stimulating hormone - 13, beta-melanocyte-stimulating hormone - 18, glucagon - 29, thyrocalcitonin - 32, ACTH - 39, parathyroid hormone - 84, beta-lipotropic hormone - 91 and growth hormone - 191 amino acid residues, alpha- and beta-melanocyte-stimulating hormones, glucagon, ACTH, parathyroid hormone and beta-lipotropic hormone do not contain disulfide bonds. Oxytocin, vasopressin and thyrocalcitonin contain one, growth hormone two and lactogenic hormone three disulfide bonds. The chemical structure of insulin is different from that of all other hormones. The insulin molecule consists of two peptide chains (A, consisting of 21, and B - of 30 amino acid residues), connected to each other by two disulfide bridges. A special group of protein-peptide hormones are pituitary hormones: luteinizing, follicle-stimulating and thyrotropic, which are complex proteins - glycoproteins. The active molecule of these substances is formed by connecting two inactive subunits (flu and beta) using non-covalent bonds.

According to the biological action of protein-peptide hormones are extremely diverse. The releasing hormones of the hypothalamus stimulate the secretion of the corresponding triple hormones by the pituitary gland. Oxytocin and vasopressin regulate the transport of water in the body and stimulate the contraction of the smooth muscles of the uterus and blood vessels, alpha and beta melanocyte-stimulating hormones increase the formation of skin pigments. Glucagon and insulin regulate carbohydrate metabolism, thyrocalcitonin and parathyroid hormone - phosphorus-calcium metabolism, lipotropic hormone - fat metabolism, growth hormone - the metabolism of proteins, fats and carbohydrates and stimulates the overall growth of the body, lactogenic hormone increases the formation of milk in the mammary glands. Other protein-peptide hormones of the pituitary gland (ACTH, luteinizing, follicle-stimulating and thyroid-stimulating) activate the function of the corresponding endocrine glands, adrenal cortex, gonads and thyroid gland.

In addition to the pituitary gland and other glands, protein-peptide hormones are also produced by the placenta, which secretes into the blood somatomammotropin, similar in chemical structure and biological properties to pituitary growth hormone, and chorionic gonadotropin, similar to luteinizing hormone. Protein-peptide hormones also include secretin, a peptide consisting of 26 amino acid residues. It is produced by the mucous membrane of the small intestine and through the blood stimulates the secretion of pancreatic juice. Protein-peptide hormones sometimes include angiotensin, which has a hypertensive effect and stimulates the secretion of aldosterone by the adrenal gland, as well as bradykinin and kallidin, which stimulate smooth muscle contraction. These substances are octa-, nona- and decapeptides and are formed from specific plasma proteins under the influence of proteolytic enzymes.

Clinical application. Many protein-peptide hormones are obtained synthetically and used in the clinic for the treatment of diseases of the endocrine glands, metabolic disorders and other diseases.

Bibliography: Chemistry and biochemistry of peptide-protein hormones, in the book: Sovr. question endocrinol., ed. N. A. Yudaeva, v. 4, M., 1972; Hormones In blood, ed. by G.H. Gray a. A. L. Bacharacb, v. 1-2, L.-N.Y., 1967.

Oct 14, 2014

Substances whose molecules consist of residues of two or more amino acids are called peptides. Chains of 10-20 amino acids form oligopeptides, and when their number increases to 50 or more, a protein is formed. Amino acid residues are linked by a special type of bond called a peptide bond. Already a hundred years ago, a method for synthesizing proteins in the laboratory became known.

Proteins are the main building material for all living organisms. Peptides, which are building blocks, can be obtained from plant, animal, and human cells. For peptides, the primary structure is distinguished - this is directly the sequence of amino acid residues, but the structure of the molecule and its spatial configuration determine their secondary structure.

What are peptides

The main types of peptides in the body:

Peptide hormones - hormones of the hypothalamus, pituitary gland, somatotropin, prolactin, adrenocorticotropic hormone, melanocyte-stimulating hormone, pancreatic and thyroid hormones, glucagon;
Neuropeptides - hormones that are formed in the central and peripheral nervous system, regulate physiological processes in the body;
Immunological hormones that have a protective function;
Peptide bioregulators that control cell function.

What are peptides for?

Being links for the construction of protein molecules, peptides themselves become the building material of the body. In the case when the production of protein molecules in the body is disrupted, the human body is exposed to negative external factors leading to the development of diseases, wear and tear and aging of the body. In case of violation of the control function, a malfunction occurs in the cells, entailing a disorder in the vital activity and functioning of the organ. And since all organs in the body are interconnected, there is a violation of the activity of the whole organ system. It is the peptides that prevent:

Development of disorders in the work of the cardiovascular system;
Disorders of the digestive system;
The occurrence of oncological diseases;
obesity;
The appearance of diabetes.

Peptides also contribute to the excretion of radionuclides and salts of heavy metals from the body.

"Information system" of the body

All the genetic information of an organism is recorded on a matrix -. The synthesis of new protein molecules occurs due to the "reading" of this information with the help of peptides. Peptides carry the "written off" information to the cells, where the synthesis of protein molecules takes place.

All peptides have a narrow working specialization, and each organ and tissue has its own personal peptides. And at the same time, peptides of a certain specialization have the same structure in different types of mammals. This discovery made it possible to create medicines based on animal peptides.

Practical application of peptides

Scientists have found out the effect of using external peptide bioregulators (BAA) on the state of health and life expectancy of a person. After the research, a statement was made that the basis of aging, as well as the occurrence of fatal diseases, including cancer, is a violation of the regulation of protein synthesis. With the artificial introduction of the corresponding peptides into the body, regenerative processes begin in cells and tissues, so you can buy peptides and help your body. Cells get the opportunity to further divide, and old cells that hardly perform their functions are replaced by new, young, healthy ones. Thus, the process is suspended, life expectancy increases. Peptides protect our body from the harmful effects of toxins, saturate them with nutrients. Unlike drugs that relieve the body of the symptoms of the disease, but do not eliminate their cause, peptides induce the restoration of the working functions of the cell, bring it to its original state.

Peptides for athletes and bodybuilders

For athletes, the intake of peptides into the body plays a huge role, primarily due to the fact that professional sports and heavy physical exertion lead the body to stress, which negatively affects the production of peptides by cells. In addition, peptides contribute to:

weight growth;
additional fat burning;
acceleration of metabolic processes.

Synthesized peptides: benefit or harm?

If the body cannot cope with the production of peptides on its own, then it is necessary to help it. Many years of scientific research has made it possible to synthesize peptides and introduce them into the body, stimulating and regulating the work of cells. Peptides act on the body at the gene level, controlling protein synthesis. Taking peptide bioregulators can significantly extend the duration of a person's life, but, in addition, it is necessary to follow the rules of a healthy lifestyle:

observe the daily routine, get up early and go to bed. Night shift work has a very negative impact on health.
eat a varied and balanced diet, giving preference to products that grow in your area. Calcium-rich dairy products, especially cottage cheese, are useful for older people, but it is better to reduce meat consumption. Control consumption of sweets and starchy foods.
drink one to two liters of water a day. It is advisable to draw water from a source or purchase a quality filter.
active physical activity: walking, swimming, cycling. You should not overload the body, but it should not be given to relax either.
undergo a periodic medical examination in order to know the weak points of the body and provide it with support in the form of bioregulators in a timely manner.

Longevity is not a myth, it is subject to everyone, you just need to make some efforts for this. You should not expect an instant effect from taking bioregulators, because there is no magic pill for old age, but you can also maintain the health of the body. This process is long, and an integrated approach is important, but the result is worth it, right?

The human body simply cannot exist normally without hormones. They are always with people, starting their development when the need arises. A variety of substances of the hormonal type in the human body function in the most active way. And most of all these substances are peptides, which play an essential role in the normal functioning of the body of each person.

Peptide hormones are unique compounds that differ in protein nature. It should be noted that peptides can be formed by glands of various types, and it is worth saying more about them:

first it is necessary to speak about the pituitary gland, and then about such glands;
parathyroid;
pancreas;
thyroid.

Nevertheless, one should not think that peptide hormones can be formed exclusively by the above methods. Peptides can be formed in tissue that contains fat, gastric cells, and certain liver and kidney cells can also take part in their formation.

If we talk about the effective mechanism by which peptides act, then there are no special differences from other substances of the active type of this nature, and there is also no dependence on the place where the hormone itself is produced. But the points of active application and the final effective effect have certain differences. Peptide hormones begin their effect on organs by binding to special receptors that are present in the cell membrane.

Moreover, a separate receptor is able to recognize only a certain hormone, that is, one that has a degree of influence on it. During this process, the formation of various enzymes begins, which act as a kind of intermediaries. It is they that influence the activation of the necessary functions in the cells, as a result of which a response type reaction begins on peptide hormones.

What peptides can begin their formation in the pituitary gland

The pituitary gland is a cerebral appendage, it is deployed in the lower region of the brain, it includes the anterior and posterior lobes. In the anterior lobe there are many cells of the glandular type, it is interesting to know which peptide hormones are in the anterior part of the pituitary gland:

thyrotropic type, which is responsible for the natural regulation of the formation of active-type hormonal compounds in the thyroid gland;
adrenocorticotropic type, which affects the increase in the activity of the adrenal cortex type;
follicle-stimulating type, which affects the function of a reproductive nature in women in a state of pregnancy;
luteinizing type, which stimulates reproductive activities in the fair sex, who are ovulating;
somatrottopic type, affecting the metabolism of fats and proteins in the human body, stimulates their growth;
prolactin. Responsible for the formation of the required amount of milk in those women who breastfeed, also affects the mother taking care of the child;
melanotropin. Responsible for the color scheme of the eyes, hair, skin.

As for the posterior pituitary lobe, no hormones are formed, but those peptides that were previously in the hypothalamus are sent there.

Are there peptides in the hypothalamus

Peptide hormones are present in the hypothalamus, and they represent three groups of the active type. The largest is the group of releasing hormones that stimulate substances of the active type of the anterior pituitary gland. Of the called liberins, they have a corresponding effect on pituitary hormones.

Considering from the impact, the production of pituitary hormones becomes more enhanced, and what is very important, this happens exactly at the time when there is an acute need for the human body in this. Nevertheless, one should not think that the production of such substances should always be enhanced, since situations are not uncommon when their action, on the contrary, is weaker. And here another hormonal group of the hypothalamus, which are called statins, comes into play.

What is regulated in the pancreas

It should be noted that peptide hormones can be produced not only in the brain, there are hormones that are produced by the pancreas, and we are talking about such important hormones as insulin and glucagon. Such a gland is located in the abdominal cavity, it is mainly engaged in hormonal production of food type.

As for insulin, it undoubtedly plays a crucial role in the activity of the human body. Examples can be given here - it has a direct effect on carbohydrate-type energy metabolism, making it easier and faster for carbohydrates to be transported to human adipose tissue and muscles. However, the main function of insulin is to control glycemia, when blood sugar begins to decrease, and therefore the structure is disturbed. And its antipode is glucagon, which is able to increase the sugar concentration in human blood, but this is done only in cases where this is really necessary.

Where else can hormones be formed

The hormone of the parathyroid type also refers to peptide substances, its formation is carried out in the glands of the parathyroid type. Such a component is characterized by increased activity, its functions are very important, it consists in the regulation of calcium metabolism in the human body. It has a depressing effect on the formation of bone-type tissue, and it owes such an influence to the peculiarities of its composition.

The thyroid gland also produces several types of hormones, and there is such a substance, which in its actions is the exact opposite of the parathyroid type hormone, it is called calcitonin, this is a peptide hormone. Without it, the exchange between calcium and phosphorus is not complete, and the cells that are involved in the construction of bone tissue begin to be stimulated. There are also substances that affect the blood composition.

Final part

As it becomes clear, peptide hormones take an active part in a variety of processes of a biological type, it is under their control that the work of the vast majority of organs of the human body and its tissues is under their control. So, they are simply irreplaceable, without them a person simply cannot live. So the mechanism of action of peptide hormones is a well-established mechanism, so that its structure cannot be violated. A lot really depends on hormonal stability.

Peptide hormones are substances produced by the endocrine glands to control various functions of the body. Mimetics are substances that mimic the actions of other substances. Analogues- These are artificially synthesized compounds that have the same properties as natural human hormones.

Peptide hormones, mimetics and analogues. Action

Hormones carry information from one organ to another, regulating a variety of bodily functions such as growth, sex drive, behavior, and sensitivity to pain.

Why are peptide hormones, mimetics and analogues banned?

Athletes use these substances for different reasons, depending on what they want to achieve. Hormones can be used for:

Stimulation of the production of own hormones;
Increase in muscle mass and strength;
Stimulates the production of red blood cells, which increases the amount of oxygen carried by the blood.

Side effects

It is difficult to estimate how much harm the use of peptide hormones, mimetics and analogues as doping can bring, since it depends on many factors, such as the characteristics of the individual organism, the type of substance, its amount. Substances that mimic the actions of natural hormones can affect the hormonal balance in the body.

It would be more correct to consider separately various prohibited peptide hormones, mimetics and analogues, such as:

Chorionic gonadotropin ((hCG), prohibited for use only for men);
Pituitary and synthetic gonadotropins ((LH), prohibited for use only for men);
Corticotrophin (ACTH, tetracosactide);
Growth Hormone (hGH);
Insulin-like growth factor (IGF-1);
Erythropoietin (EPO);
Insulin

Chorionic gonadotropin

Human chorionic gonadotropin (hCG)- This is a hormone produced by the placenta during pregnancy, it is able to increase the secretion of natural male and female steroids. In medicine, it is used to treat infertility, undescended testicles, and delayed puberty.
The use of hCG by men stimulates the testicles to rapidly produce testosterone, so its use is equivalent to the use of testosterone. Its use is prohibited only for men. It is mainly used by anabolic steroid users in an attempt to overcome the harmful effects of their use on their testicles, or as a masking agent.

Since hCG stimulates the production of testosterone, the side effects of its use are the same as those of anabolic steroids. In addition, the following side effects are possible:

headache;
irritability;
depression;
apathy;
gynecomastia (breast growth in men)

Pituitary and synthetic gonadotropins.

These are hormones produced by the pituitary gland, including luteinizing hormone (LH). LH stimulates the functioning of the testicles, as well as the production of sex hormones in men and women.

In LH medicine in the treatment of female and male infertility. In women, it stimulates ovulation, and in men, the production of testosterone, which is equivalent to its use. The use of LH is prohibited for men only.

Synthetic gonadotropins such as tamoxifen, cyclophenyl and clomiphene regulate the production of gonadotropin. Side effects from the use of each of these substances are different.

Corticotropins

Corticotropin (adrenocorticotropin ACTH) is a natural hormone produced by the pituitary gland to stimulate the secretion of corticosteroids. In medicine, it is used as a diagnostic tool to analyze the function of the adrenal cortex, and to treat certain neurological disorders such as infantile paralysis and multiple sclerosis. It is used by athletes to increase the level of natural corticosteroids, which provides an anti-inflammatory effect, as well as a feeling of euphoria. The use of corticotropin is equivalent to the use of glucocorticosteroids and is therefore prohibited.

Short-term side effects from ACTH use include digestive upset, ulcers, and psychological effects such as irritability. In addition, it is possible:

softening of the connective tissue;
weakening of damaged areas of muscles, bones, tendons and ligaments;
osteoporosis;
cataract;
accumulation of fluid in the body;
high blood sugar (hyperglycemia);
reduced resistance to infections.

A growth hormone

Human Growth Hormone (hGH) produced by the pituitary gland. It actively stimulates the growth of muscles, bones and other tissues, and also promotes fat burning. It is necessary for the normal growth and development of children, as well as the maintenance of metabolism in adults.

In medicine, it is used to treat children with reduced pituitary function. Usually it is used only in the treatment of those children in whom the centers of bone growth are not yet closed. Since 1989, it has also been used to treat adults with growth hormone deficiency. These people have:

normalizes the constitution of the body (promotes the growth of bones and muscles and reduces fat reserves);
improves well-being (in particular mood and energy level);
normalizes metabolism, including cholesterol and other risk factors for vascular diseases.

There are many reasons why athletes may start taking growth hormone, for example, to increase muscle mass and reduce fat stores. Another incentive to take it may be the desire for the child to grow taller.

Scientific studies mention other positive effects of taking growth hormone (this is only relevant for adults with a deficiency of this hormone), such as an increase in cardiac output during exercise, increased sweating, improved thermoregulation of the body, increased breakdown of fats, which provides additional energy. to increase stamina, and also possibly to strengthen ligaments and reduce the healing time of injuries. Athletes could not help but be interested in such properties of the hormone, but once again it should be emphasized that only patients with growth hormone deficiency took part in the studies.

Side effects of growth hormone use may include:

diabetes;
heart failure;
high blood pressure;
delay in the excretion of water and sodium from the body;
accelerated osteoarthritis;
gigantism in young athletes (overgrowth of the skeleton).

Insulin-like growth factor

Insulin-like growth factor I (IGF-I) is a hormone produced primarily by the liver and regulated by growth hormone and insulin. IGF-I stimulates protein synthesis and inhibits the destruction of muscle cells, which helps to increase muscle mass and reduce body fat.
IGF-I has been used in medicine to treat dwarfism in children, as well as to treat children who have antibodies that reduce the effectiveness of growth hormone.

Athletes use IGF-I for its anabolic properties. Among others, the following side effects are possible from its use:

low blood sugar (hypoglycemia);
acromegaly in adults (deformed growth of internal organs,
bones and parts of the face, growth and thickening of the fingers, ears and skin);
headaches and joint pain;
intermittent muscle weakness due to degenerative changes in the joints.

Erythropoietin (EPO)

Erythropoietin (EPO) is a hormone produced by the kidneys that stimulates the formation of red blood cells. In medical practice, a synthetic form of EPO is used to treat anemia associated with chronic renal failure.

EPO can be used by athletes to increase the amount of oxygen transported in the body, which increases with an increase in red blood cell count. This extra oxygen is delivered to the muscles, which improves endurance. Most often, long-distance runners, skiers and cyclists come across this doping.
Here are some of the serious consequences of taking erythropoietin:
blood clots,
increased risk of blockage of blood vessels and heart attack,
the risk of contracting infections such as hepatitis and AIDS due to the lack of sterility when performing injections.
For athletes such as long-distance runners, etc. the risk of blockage of blood vessels increases many times due to dehydration.

Insulin

Insulin It is a hormone produced by the pancreas and is involved in the regulation of blood sugar levels. It is involved in the metabolism of carbohydrates, fats and proteins. In medicine, it is used in the treatment of diabetes.

Athletes have taken it along with anabolic steroids, clenbuterol and/or growth hormone in an attempt to increase muscle mass. The question of whether insulin contributes to this result is undisputed, in contrast to the fact that with its use in this way the risk of serious side effects is very high. It is not excluded, including the lethal outcome from the use of insulin.

Side effects include low blood sugar (hypoglycemia) with accompanying effects such as tremors, nausea, weakness, shortness of breath, drowsiness, coma, brain damage, and death.
Insulin is approved for use only by those athletes who are insulin-dependent diabetics. In this case, it is necessary to provide an extract from the medical history prepared by the endocrinologists or the team doctor. The Athlete should check with their National or International Federation for notification requirements.

Modern methods of analysis do not yet allow "catching" athletes on the use of insulin.

Conclusion

No human body can exist without hormones. They accompany people everywhere, being actively developed at the moment when they are needed. A wide variety of hormonal substances function in the human body. The lion's share of these hormones is accounted for by peptides.

What are and what is the basis of the action of peptides

Peptide hormones are substances of a protein nature that are produced by various endocrine glands in the body. These glands include the following:

However, peptides are produced not only in specific glands, some of them are produced by adipose tissue, stomach cells, some cells of the liver and kidneys.

The mechanism of action of peptide hormones is typical for all active substances of this nature and does not depend on the place where the hormone itself is produced. The points of application of activity and the final effect of the impact differ. All hormones act on target organs by binding to special receptors located on the cell membrane. Each receptor recognizes only “its own” hormone, only the one that can influence it. In the cell, under the influence of the peptide bound to the receptor, mediators are formed in the form of various enzymes. These enzymes in the cell activate the necessary functions, and there is an effective response to the action of the peptide hormone.

Why does a person need the pituitary gland, and what peptides are formed there?

The pituitary gland is an appendage of the brain, which is located on its lower part. Consists of anterior and posterior lobe. It is the anterior lobe that consists of a large number of glandular cells. The following is a list of anterior pituitary peptide hormones.

The posterior lobe of the pituitary gland, the neurohypophysis, normally does not produce hormones. Peptides are transported there from the hypothalamus, and here they are deposited. The most important of the stored hormones are vasopressin and oxytocin. Vasopressin performs two main functions: regulation of water constancy in the body and vasoconstriction. Oxytocin optimizes the process of delivery and is involved in lactation, contributing to the easy release of milk from the maternal glands.

The pituitary gland is closely related to the hypothalamus. Together with it, it forms the regulatory hypothalamic-pituitary system, which is involved in many body functions. The hypothalamus is not a gland. It is a collection of cells in a small space in the diencephalon. However, the cells located in the hypothalamus are active producers of vital hormones of the peptide structure.

Are there peptides in the hypothalamus?

All peptide hormones of the hypothalamus are three different groups of active substances. The largest group is releasing hormones. They have a stimulating effect on the active substances of the anterior pituitary gland. They are called liberins and affect, as the name suggests, the corresponding hormones in the pituitary gland. The main ones are the following:

corticoliberin;
thyroliberin;
somatoliberin;
folliberin;
luliberin.

Thanks to the influence of liberins, the production of pituitary hormones is enhanced at those moments when the human body needs it. However, it is not always necessary to increase the production of active components of the pituitary gland. In some situations, on the contrary, it is necessary to slow down the hormones of the pituitary gland. For this, there is a second group of hormones of the hypothalamus. These are statins that inhibit the activity of the active components of the pituitary gland corresponding to the name.

somatostatin;
prolactostatin;
melanostatin.

What do pancreatic peptides regulate?

Peptide hormones are produced not only in the parts of the brain. The two most important hormones, insulin and glucagon, are produced by the pancreas. The pancreas is an organ located in the abdominal cavity, in the epigastrium. It has secreting activity internal, aimed at the production of digestive hormones, and external, in which hormones of a peptide nature are formed. The formation of these active components occurs in special areas of the gland - the islets of Langerhans.

Insulin is the most important peptide hormone in the body. It is involved in the exchange of carbohydrate energy, improves the transport of carbohydrates into muscles and adipose tissue. However, the main effect is glycemic control - lowering the concentration of sugar in the blood. The antipode is the second peptide pancreatic hormone - glucagon. Its participation in energy metabolism is to raise the concentration of sugar in the blood when the body needs it.

Can peptides be formed somewhere else?

Peptide hormones also include parathyroid hormone, which is produced in the parathyroid glands. The function of this active ingredient is aimed at regulating calcium metabolism in the body. It inhibits the formation of bone tissue and is secreted when the level of calcium in the blood decreases.

Several active peptide substances are produced in the thyroid gland. One of them is a complete parathyroid hormone antagonist. Its name is calcitonin. It is involved in the exchange of calcium and phosphorus and stimulates the activity of bone tissue builders.

Some hormones can affect the composition of the blood. They are called erythropoietins, which control the formation of red blood cells and the formation of hemoglobin in the blood, and thrombopoietins, which are involved in the formation of platelets. These peptide hormones are produced by the liver and kidneys.

Conclusion

Thus, peptide hormones are involved in many biological processes of the body, play a crucial role in controlling the functioning of most organs and systems. In many cases, they are irreplaceable, on which the very existence of a person depends.