Hormone is a chemical substance that is a biologically active substance produced by glands internal secretion, enters the bloodstream and affects tissues and organs. Today, scientists have been able to decipher the structure of the bulk of hormonal substances and have learned to synthesize them.
Without pancreatic hormones, the processes of dissimilation and assimilation are impossible; the synthesis of these substances is carried out by the endocrine parts of the organ. If the functioning of the gland is disrupted, a person suffers from many unpleasant diseases.
The pancreatic gland is a key organ digestive system, it performs endocrine and excretory functions. It produces hormones and enzymes, without which it is impossible to maintain biochemical balance in the body.
The pancreas consists of two types of tissue; the secretory part connected to the duodenum is responsible for the secretion of pancreatic enzymes. Most important enzymes these include lipase, amylase, trypsin and chymotrypsin. If insufficiency is observed, prescribe enzyme preparations pancreas, use depends on the severity of the disorder.
The production of hormones is ensured by islet cells; the endocrine part occupies no more than 3% of the total mass of the organ. The islets of Langerhans produce substances that regulate metabolic processes:
Endocrine disorders in the pancreas cause the development of a number of dangerous diseases, with hypofunction, diabetes mellitus, glucosuria, polyuria are diagnosed; with hyperfunction, a person suffers from hypoglycemia, obesity varying degrees gravity. Hormone problems also occur if a woman long time takes contraceptives.
Scientists have identified the following hormones secreted by the pancreas: insulin, pancreatic polypeptide, glucagon, gastrin, kallikrein, lipocaine, amylin, vagotinin. All of them are produced by islet cells and are necessary for the regulation of metabolism.
The main pancreatic hormone is insulin; it is synthesized from the precursor proinsulin; its structure includes about 51 amino acids.
The normal concentration of substances in the body of a person over 18 years of age is from 3 to 25 µU/ml of blood. acute failure Insulin develops diabetes mellitus.
Thanks to insulin, the transformation of glucose into glycogen and the biosynthesis of hormones are triggered digestive tract is kept under control, the formation of triglycerides, higher fatty acids.
In addition, insulin reduces the level of harmful cholesterol in the bloodstream, becoming a prophylactic against vascular atherosclerosis. Additionally, transport to cells is improved:
Insulin promotes protein biosynthesis on ribosomes, inhibits the process of converting sugar from non-carbohydrate substances, lowers the concentration of ketone bodies in human blood and urine, and reduces the permeability of cell membranes to glucose.
The insulin hormone is capable of significantly increasing the transformation of carbohydrates into fats with subsequent deposition, is responsible for the stimulation of ribonucleic (RNA) and deoxyribonucleic (DNA) acids, increases the supply of glycogen accumulated in the liver, muscle tissue Glucose becomes the key regulator of insulin synthesis, but at the same time the substance does not affect the secretion of the hormone.
The production of pancreatic hormones is controlled by compounds:
Given that early diagnosis metabolic disorders and diabetes mellitus, adequate therapy manages to alleviate the human condition.
At excessive secretion insulin, men are at risk of impotence, patients of any gender experience problems with vision, asthma, bronchitis, hypertension, premature baldness, increases the likelihood of myocardial infarction, atherosclerosis, acne and dandruff.
If too much insulin is produced, the pancreas itself suffers and becomes overgrown with fat.
Sugar level
To normalize metabolic processes in the body, it is necessary to take pancreatic hormones. They should be used strictly as prescribed by the endocrinologist.
Classification of pancreatic hormone preparations: short-acting, average duration, long acting Your doctor may prescribe a specific type of insulin or recommend a combination of insulins.
Indications for prescribing insulin short term action becomes diabetes and excessive amounts of sugar in the bloodstream when sweetener tablets do not help. These products include Insuman, Rapid, Insuman-Rap, Actrapid, Homo-Rap-40, Humulin.
The doctor will also offer the patient medium-term insulins: Mini Lente-MK, Homofan, Semilong-MK, Semilente-MS. There are also long-acting pharmacological agents: Super Lente-MK, Ultralente, Ultratard-NM. Insulin therapy is usually lifelong.
Glucagon
This hormone is included in the list of substances of a polypeptide nature, containing about 29 different amino acids, in the body healthy person glucagon levels range from 25 to 125 pg/ml of blood. It is considered a physiological insulin antagonist.
Hormonal preparations of the pancreas, containing animal or, stabilize the levels of monosaccharides in the blood. Glucagon:
Glucagon is able to increase blood circulation in the kidneys, activate metabolism, keep the conversion of non-carbohydrate foods into sugar under control, and increase glycemic levels due to the breakdown of glycogen by the liver.
The substance stimulates gluconeogenesis, in large quantities has an effect on the concentration of electrolytes, has antispasmodic effect, lowers calcium and phosphorus levels, starts the process of fat breakdown.
The biosynthesis of glucagon will require the intervention of insulin, secretin, pancreozymin, gastrin and somatotropin. In order for glucagon to be released, there must be a normal supply of proteins, fats, peptides, carbohydrates and amino acids.
Somatostatin
Somatostatin is unique substance, it is produced by the delta cells of the pancreas and the hypothalamus.
The hormone is necessary to inhibit the biological synthesis of pancreatic enzymes, lower glucagon levels, and inhibit the activity of hormonal compounds and the hormone serotonin.
Without somatostatin, adequate absorption of monosaccharides from small intestine into the bloodstream, reduce gastrin secretion, inhibit blood flow in abdominal cavity, peristalsis of the digestive tract.
Vasointense peptide
This neuropeptide hormone is secreted by cells of various organs: the back and brain, thin section intestines, pancreas. The level of the substance in the bloodstream is quite low and remains almost unchanged after eating. The main functions of the hormone include:
In addition, there is stimulation of somatostatin, glucagon and insulin, and the launch of the production of pepsinogen in the cells of the stomach. Subject to availability inflammatory process in the pancreas, a disruption in the production of neuropeptide hormone begins.
Another substance produced by the gland is pancreatic polypeptide, but its effect on the body has not yet been fully studied. The physiological concentration in the bloodstream of a healthy person can vary from 60 to 80 pg/ml; excessive production indicates the development of neoplasms in the endocrine part of the organ.
The hormone amylin helps optimize the amount of monosaccharides; it prevents their entry into the bloodstream increased amount glucose. The role of the substance is manifested by suppression of appetite (anorexic effect), stopping the production of glucagon, stimulating the formation of somatostatin, and weight loss.
Lipocaine takes part in the activation of phospholipids, the oxidation of fatty acids, enhances the effect of lipotropic compounds, and becomes a measure for the prevention of fatty liver degeneration.
The hormone kallikrein is produced by the pancreas, but remains in an inactive state in it; it begins to work only after entering the duodenum. It lowers glycemic levels and lowers blood pressure. To stimulate the hydrolysis of glycogen in the liver and muscle tissue, the hormone vagotonin is produced.
Gastrin is secreted by gland cells, the gastric mucosa, a hormone-like compound increases acidity, triggers the formation of the proteolytic enzyme pepsin, and normalizes the digestive process. It also activates the production of intestinal peptides, including secretin, somatostatin, cholecystokinin. They are important for the intestinal phase of digestion.
Substance centroptein of protein nature:
For this reason, centroptein deficiency is often associated with pancreatitis and erectile dysfunction in men. Every year more and more new pancreatic hormone preparations appear on the market, their presentation is carried out, which makes it easier to solve such disorders, and they have fewer and fewer contraindications.
Pancreatic hormones play a key role in regulating the body’s vital functions, so it is necessary to have an idea of the structure of the organ, take care of your health, and listen to your well-being.
The treatment of pancreatitis is described in the video in this article.
Pancreatic hormone preparations
The human pancreas, mainly in its caudal part, contains approximately 2 million islets of Langerhans, constituting 1% of its mass. The islets consist of a-, b- and l-cells that produce glucagon, insulin and somatostatin (inhibiting the secretion of growth hormone), respectively.
In this lecture, we are interested in the secret of b-cells of the islets of Langerhans - INSULIN, since insulin preparations are currently the leading antidiabetic agents.
Insulin was first isolated in 1921 by Banting, Best - for which they received the Nobel Prize. Insulin was isolated in crystalline form in 1930 (Abel).
Normally, insulin is the main regulator of blood glucose levels. Even a slight increase in blood glucose causes insulin secretion and stimulates its further synthesis by b-cells.
The mechanism of action of insulin is due to the fact that hubbub enhances the absorption of glucose by tissues and promotes its conversion into glycogen. Insulin, by increasing the permeability of cell membranes to glucose and reducing the tissue threshold to it, facilitates the penetration of glucose into cells. In addition to stimulating the transport of glucose into the cell, insulin stimulates the transport of amino acids and potassium into the cell.
Cells are very permeable to glucose; In them, insulin increases the concentration of glucokinase and glycogen synthetase, which leads to the accumulation and deposition of glucose in the liver in the form of glycogen. In addition to hepatocytes, striated muscle cells are also glycogen depots.
With a lack of insulin, glucose will not be properly absorbed by the tissues, which will result in hyperglycemia, and with very high levels of glucose in the blood (more than 180 mg/l) and glycosuria (sugar in the urine). Hence Latin name diabetes mellitus: "Diabetes mellitus" (diabetes mellitus).
The tissue requirement for glucose varies. In a number of fabrics
The brain, visual epithelial cells, sperm-producing epithelium - energy production occurs only due to glucose. Other tissues may use fatty acids in addition to glucose to produce energy.
In diabetes mellitus (DM), a situation arises in which, amid “abundance” (hyperglycemia), cells experience “hunger.”
In the patient’s body, in addition to carbohydrate metabolism, other types of metabolism are also distorted. Insulin deficiency results in a negative nitrogen balance, where amino acids are primarily used in gluconeogenesis, the wasteful conversion of amino acids into glucose, which produces 56 g of glucose from 100 g of protein.
Fat metabolism is also disrupted, and this is primarily due to an increase in the blood level of free fatty acids (FFA), from which fatty acids are formed. ketone bodies(acetoacetic acid). The accumulation of the latter leads to ketoacidosis up to coma (coma is an extreme degree of metabolic disorder in diabetes). In addition, under these conditions, cell resistance to insulin develops.
According to WHO, currently the number of people with diabetes on the planet has reached 1 billion people. Diabetes ranks third in mortality after cardiovascular pathology And malignant neoplasms Therefore, diabetes is an acute medical and social problem that requires emergency measures to solve.
By modern classification WHO population of patients with diabetes is divided into two main types
1. Insulin-dependent diabetes mellitus (formerly called juvenile diabetes mellitus) - IDDM (DM-I) develops as a result of the progressive death of b-cells, and is therefore associated with insufficient insulin secretion. This type debuts before the age of 30 years and is associated with a multifactorial mode of inheritance, as it is associated with the presence of a number of histocompatibility genes of the first and second classes, for example, HLA-DR4 and HLA-DR3. Individuals with both -DR4 and -DR3 antigens are at greatest risk of developing IDDM. The proportion of patients with IDDM is 15-20% of total number.
2. Non-insulin-dependent diabetes mellitus - NIDDM (DM-II). This form of diabetes is called adult-onset diabetes because it usually appears after age 40.
The development of this type of diabetes is not associated with the human major histocompatibility system. In patients with this type of diabetes, normal or moderately reduced numbers of insulin-producing cells are found in the pancreas and it is now believed that NIDDM develops as a result of a combination of insulin resistance and functional impairment the ability of the patient's b-cells to secrete a compensatory amount of insulin. The proportion of patients with this form of diabetes is 80-85%.
In addition to two main types, there are:
3. Diabetes associated with malnutrition.
4. Secondary, symptomatic diabetes (endocrine origin: goiter, acromegaly, pancreatic diseases).
5. Diabetes in pregnant women.
Currently, a certain methodology has emerged, that is, a system of principles and views on the treatment of patients with diabetes, the key of which are:
1) compensation for insulin deficiency;
2) correction of hormonal and metabolic disorders;
3) correction and prevention of early and late complications.
According to the latest treatment principles, the following three traditional components remain the main methods of treatment for patients with diabetes:
2) insulin preparations for patients with IDDM;
3) oral hypoglycemic agents for patients with NIDDM.
In addition, it is important to adhere to the regime and degree physical activity. Among pharmacological agents There are two main groups of drugs used to treat patients with diabetes:
I. Insulin preparations.
II. Synthetic oral (tablet) antidiabetic agents.
The pancreas produces two hormones: glucagon(α-cells) and insulin(β-cells). The main role of glucagon is to increase the concentration of glucose in the blood. One of the main functions of insulin, on the contrary, is to reduce the concentration of glucose in the blood.
Preparations of pancreatic hormones are traditionally considered in the context of the treatment of a very severe and common disease - diabetes mellitus. The problem of the etiology and pathogenesis of diabetes mellitus is very complex and multifaceted, so here we will pay attention to only one of the key links in the pathogenesis of this pathology: a violation of the ability of glucose to penetrate into cells. As a result, an excess of glucose appears in the blood, and the cells experience severe deficiency. The energy supply to cells suffers, and carbohydrate metabolism is disrupted. Drug treatment diabetes mellitus is aimed precisely at eliminating this situation.
The trigger for insulin secretion is an increase in blood glucose concentration. In this case, glucose penetrates into the β-cells of the pancreas, where it breaks down to form adenosine triphosphoric acid (ATP) molecules. This leads to inhibition of ATP-dependent potassium channels with subsequent disruption of the release of potassium ions from the cell. Depolarization of the cell membrane occurs, during which voltage-gated calcium channels open. Calcium ions enter the cell and, being physiological stimulant exocytosis, activate the secretion of insulin into the blood.
Once in the blood, insulin binds to specific membrane receptors, forming a transport complex, in the form of which it penetrates into the cell. There, through a cascade of biochemical reactions, it activates membrane transporters GLUT-4, designed to transfer glucose molecules from the blood into the cell. Glucose that enters the cell is recycled. In addition, in hepatocytes, insulin activates the enzyme glycogen synthetase and inhibits phosphorylase.
As a result, glucose is consumed for glycogen synthesis, and its concentration in the blood decreases. In parallel, hexakinase is activated, which activates the formation of glucose-6-phosphate from glucose. The latter is metabolized in reactions Krebs cycle. The consequence of the described processes is a decrease in the concentration of glucose in the blood. In addition, insulin blocks the enzymes of gluconeogenesis (the process of formation of glucose from non-carbohydrate products), which also helps to reduce plasma glucose levels.
Sources:
1. Lectures on pharmacology for higher medical and pharmaceutical education / V.M. Bryukhanov, Ya.F. Zverev, V.V. Lampatov, A.Yu. Zharikov, O.S. Talalaeva - Barnaul: Spektr Publishing House, 2014.
2. Pharmacology with formulation / Gaevy M.D., Petrov V.I., Gaevaya L.M., Davydov V.S., - M.: ICC March, 2007.
PREPARATIONS OF HORMONES AND THEIR ANALOGUES. Part 1
Hormones are chemical substances that are biologically active substances, produced by the endocrine glands, entering the blood and acting on target organs or tissues.
The term "hormone" comes from the Greek word "hormao" - to excite, force, encourage activity. Currently, it has been possible to decipher the structure of most hormones and synthesize them.
According to their chemical structure, hormonal drugs, like hormones, are classified:
a) protein hormones and peptide structure(preparations of hormones of the hypothalamus, pituitary gland, parathyroid and pancreas, calcitonin);
b) amino acid derivatives (iodine-containing thyronine derivatives - hormone preparations thyroid gland, adrenal medulla);
c) steroid compounds (preparations of hormones of the adrenal cortex and gonads).
In general, endocrinology today is studied by more than 100 chemicals, synthesized in various organs and systems of the body by specialized cells.
Distinguish the following types hormonal pharmacotherapy:
1) replacement therapy(for example, administering insulin to patients diabetes mellitus);
2) inhibitory, depressive therapy to suppress the production of one’s own hormones when they are in excess (for example, in thyrotoxicosis);
3) symptomatic therapy, when the patient has no hormonal disorders in principle, no, but the doctor prescribes hormones for other indications - for severe course rheumatism (as anti-inflammatory drugs), severe inflammatory diseases eyes, skin, allergic diseases etc.
REGULATION OF HORMONE SYNTHESIS IN THE BODY
The endocrine system, together with the central nervous system and the immune system and under their influence, regulates the homeostasis of the body. The relationship between the central nervous system and endocrine system carried out through the hypothalamus, the neurosecretory cells of which (responding to acetylcholine, norepinephrine, serotonin, dopamine) synthesize and secrete various releasing factors and their inhibitors, the so-called liberins and statins, which enhance or block the release of the corresponding tropic hormones from the anterior pituitary gland (that is, the adenohypophysis ). Thus, releasing factors of the hypothalamus, acting on the adenohypophysis, change the synthesis and release of hormones of the latter. In turn, the hormones of the anterior pituitary gland stimulate the synthesis and release of target organ hormones.
The following hormones are synthesized in the adenohypophysis (anterior lobe):
Adrenocorticotropic (ACTH);
Somatotropic (STG);
Follicle stimulating and luteotropic hormones(FSH, LTG);
Thyroid-stimulating hormone(TSG).
In the absence of adenohypophysis hormones, the target glands not only stop functioning, but also atrophy. On the contrary, with an increase in the blood level of hormones secreted by the target glands, the rate of synthesis of releasing factors in the hypothalamus changes and the sensitivity of the pituitary gland to them decreases, which leads to a decrease in the secretion of the corresponding tropic hormones of the adenohypophysis. On the other hand, when the level of target gland hormones in the blood plasma decreases, the release of releasing factor and the corresponding tropic hormone increases. Thus, hormone production is regulated according to the principle feedback: the lower the concentration of target gland hormones in the blood, the greater the production of hormone regulators of the hypothalamus and hormones of the anterior pituitary gland. It is very important to remember this when carrying out hormonal therapy, since hormonal drugs in the patient’s body inhibit the synthesis of his own hormones. In this regard, when prescribing hormonal drugs, you should full assessment the patient's condition in order to avoid irreparable mistakes.
MECHANISM OF ACTION OF HORMONES (DRUGS)
Hormones, depending on their chemical structure, can have an effect on the genetic material of the cell (on the DNA of the nucleus), or on specific receptors located on the surface of the cell, on its membrane, where they disrupt the activity of adenylate cyclase or change the permeability of the cell to small molecules (glucose, calcium), which leads to changes functional state cells.
Steroid hormones Having contacted the receptor, they migrate into the nucleus, bind to specific areas of chromatin and, thus, increase the rate of synthesis of specific m-RNA into the cytoplasm, where the rate of synthesis of a specific protein, for example, an enzyme, increases.
Catecholamines, polypeptides, protein hormones change the activity of adenylate cyclase, increase the content of cAMP, as a result of which the activity of enzymes, membrane permeability of cells, etc. change.
PREPARATIONS OF PANCREAS HORMONES
The human pancreas, mainly in its caudal part, contains approximately 2 million islets of Langerhans, constituting 1% of its mass. The islets are composed of alpha, beta and delta cells that produce glucagon, insulin and somatostatin (inhibiting the secretion of growth hormone), respectively.
In this lecture, we are interested in the secret of beta cells of the islets of Langerhans - INSULIN, since insulin preparations are currently the leading antidiabetic agents.
Insulin was first isolated in 1921 by Banting, Best - for which they received the Nobel Prize in 1923. Insulin was isolated in crystalline form in 1930 (Abel).
Normally, insulin is the main regulator of blood glucose levels. Even a slight increase in blood glucose causes insulin secretion and stimulates its further synthesis by beta cells.
The mechanism of action of insulin is due to the fact that hubbub enhances the absorption of glucose by tissues and promotes its conversion into glycogen. Insulin, by increasing the permeability of cell membranes to glucose and reducing the tissue threshold to it, facilitates the penetration of glucose into cells. In addition to stimulating the transport of glucose into the cell, insulin stimulates the transport of amino acids and potassium into the cell.
Cells are very permeable to glucose; In them, insulin increases the concentration of glucokinase and glycogen synthetase, which leads to the accumulation and deposition of glucose in the liver in the form of glycogen. In addition to hepatocytes, striated muscle cells are also glycogen depots.
With a lack of insulin, glucose will not be properly absorbed by the tissues, which will result in hyperglycemia, and with very high levels of glucose in the blood (more than 180 mg/l) and glycosuria (sugar in the urine). Hence the Latin name for diabetes: “Diabetes mellitus” (diabetes).
The tissue requirement for glucose varies. In a number of tissues - the brain, cells of the visual epithelium, sperm-producing epithelium - energy production occurs only due to glucose. Other tissues may use fatty acids in addition to glucose to produce energy.
In diabetes mellitus, a situation arises in which, amid “abundance” (hyperglycemia), cells experience “hunger.”
In the patient’s body, in addition to carbohydrate metabolism, other types of metabolism are also distorted. Insulin deficiency results in a negative nitrogen balance, where amino acids are primarily used in gluconeogenesis, the wasteful conversion of amino acids into glucose, which produces 56 g of glucose from 100 g of protein.
Fat metabolism is also impaired, and this is primarily due to an increase in the blood level of free fatty acids (FFA), from which ketone bodies (acetoacetic acid) are formed. The accumulation of the latter leads to ketoacidosis up to coma (coma is an extreme degree of metabolic disorder in diabetes mellitus). In addition, under these conditions, cell resistance to insulin develops.
According to WHO, currently the number of people with diabetes on the planet has reached 1 billion people. In terms of mortality, diabetes ranks third after cardiovascular pathology and malignant neoplasms, therefore diabetes mellitus is an acute medical and social problem that requires emergency measures to solve.
According to the current WHO classification, the population of patients with diabetes mellitus is divided into two main types:
1. Insulin-dependent diabetes mellitus (formerly called juvenile diabetes mellitus) - IDDM (DM-I) develops as a result of the progressive death of beta cells, and is therefore associated with insufficient insulin secretion. This type debuts before the age of 30 years and is associated with a multifactorial type of inheritance, as it is associated with the presence of a number of histocompatibility genes of the first and second classes, for example, HLA-DR4 and
HLA-DR3. Individuals with the presence of both antigens -DR4 and
DR3 are at greatest risk of developing insulin-dependent diabetes mellitus.
The proportion of patients with insulin-dependent diabetes mellitus is 15-20% of the total number.
2. Non-insulin-dependent diabetes mellitus - NIDDM - (DM-II). This form of diabetes is called adult-onset diabetes because it usually appears after age 40.
The development of this type of diabetes mellitus is not associated with the human major histocompatibility system. In patients with this type of diabetes, a normal or moderately reduced number of insulin-producing cells is found in the pancreas, and it is currently believed that NIDDM develops as a result of a combination of insulin resistance and a functional impairment in the ability of the patient's beta cells to secrete compensatory amounts of insulin. The proportion of patients with this form of diabetes is 80-85%.
In addition to two main types, there are:
3. Diabetes mellitus associated with malnutrition.
4. Secondary, symptomatic diabetes mellitus (endocrine origin: goiter, acromegaly, pancreatic diseases).
5. Diabetes in pregnant women.
Currently, a certain methodology has emerged, that is, a system of principles and views on the treatment of patients with diabetes, the key of which are:
1) compensation for insulin deficiency;
2) correction of hormonal and metabolic disorders;
3) correction and prevention of early and late complications.
According to the latest treatment principles, the following three traditional components remain the main methods of treatment for patients with diabetes:
2) insulin preparations for patients with insulin-dependent diabetes mellitus;
3) oral hypoglycemic agents for patients with non-insulin-dependent diabetes mellitus.
In addition, compliance with the regime and degree of physical activity is important. Among the pharmacological agents used to treat patients with diabetes, there are two main groups of drugs:
I. Insulin preparations.
II. Synthetic oral (tablet) antidiabetic agents.
