4.3 Hormones and the Endocrine System – Human Biology 2nd edition

The endocrine system produces hormones that function to control and regulate many different body processes. The endocrine system coordinates with the nervous system to control the functions of the other organ systems. Cells of the endocrine system produce molecular signals called hormones. These cells may compose endocrine glands, may be tissues or may be located in organs or tissues that have functions in addition to hormone production. Hormones circulate throughout the body and stimulate a response in cells that have receptors able to bind with them. The changes brought about in the receiving cells affect the functioning of the organ system to which they belong. Many of the hormones are secreted in response to signals from the nervous system, thus the two systems act in concert to effect changes in the body.

Hormones

Maintaining balance within the body requires the coordination of many different systems and organs. One mechanism of communication between neighboring cells, and between cells and tissues in distant parts of the body, occurs through the release of chemicals called hormones. Hormones are released into body fluids, usually blood, which carries them to their target cells where they elicit a response. The cells that secrete hormones are often located in specific organs, called endocrine glands, and the cells, tissues, and organs that secrete hormones make up the endocrine system. Examples of endocrine organs include the pancreas, which produces the hormones insulin and glucagon to regulate blood-glucose levels, the adrenal glands, which produce hormones such as epinephrine and norepinephrine that regulate responses to stress, and the thyroid gland, which produces thyroid hormones that regulate metabolic rates. In addition, many organs in other body systems such as the reproductive system also secrete hormones and are therefore also part of endocrine system.

The level of hormones present in the blood is directly related to the magnitude of the responses, or actions, performed by the target cells.  For this reason, the body has evolved mechanisms to tightly regulate the level of hormone production for many hormones.  The release of hormones by endocrine cells is usually related to the amount of stimulus the receive.  A stimulus is any variable that can change the level of hormone secreted by an endocrine cell; common stimuli include nutrients, neurotransmitters, and even other hormones.  Most stimuli have a positive effect on endocrine cells, that is, with increasing amounts of stimuli increasing amounts of hormone are secreted. Some stimuli are negative regulators of endocrine cells, however.  When increased negative stimuli are present, hormone secretion decreases.  Many endocrine cells integrate inputs from multiple stimuli to regulate their level of hormone secretion.

How Hormones Work

Hormones cause changes in target cells by binding to specific cell-surface or intracellular hormone receptors, molecules embedded in the cell membrane or floating in the cytoplasm with a binding site that matches a binding site on the hormone molecule. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on or in many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Different types of cells can also respond to hormones in different ways.  For example, immune cell function is decreased when the hormone cortisol acts upon them, but cortisol causes liver cells to do something completely different, release glucose into the blood. Cells can have many receptors for the same hormone but often also possess receptors for different types of hormones.

Glossary

endocrine gland

an organ containing endocrine cells, cells that secrete hormones

hormone

a chemical secreted by an endocrine gland into body fluids (usually blood) that affects the function of target cells

hormone receptor

a molecule located on the surface of a cell, or inside it, that binds to a hormone; binding of a hormone to its receptor causes changes in the cell with the receptor

stimulus

a signal that increases or decreases the level of hormone secreted by an endocrine cell

target

a cell that expresses a hormone receptor, and changes its functions after the hormone binds to the receptor

Endocrine and Reproductive Systems

The Endocrine System

The endocrine system is similar to the nervous system, in that both systems send messages around the body. The endocrine system releases chemicals called hormones into the bloodstream. When these hormones reach target cells within the body, receptors on the target cells react, triggering a particular body response. For example, when you are feeling nervous, the hormone epinephrine is released into the bloodstream. When epinephrine reaches receptors on target cells, your heart rate increases, and your skeletal muscles become tense as part of the fight-or-flight response.

The speed at which hormones travel in the bloodstream is slow compared with the speed of nerve impulses. Thus, the endocrine system tends to regulate body processes that happen slowly over a long period of time. These processes include cell growth and development, metabolism, sexual function, and reproduction.

Glands are organs that produce and release substances. In the case of the endocrine system, these substances are hormones. Glands are found in the head and body, but not in the arms or legs. Different types of glands produce different types of hormones, and each hormone produces a unique effect.

Pituitary Gland

The pituitary gland is located in the brain and is connected to and controlled by the hypothalamus. The hypothalamus is an area of the brain that connects the nervous system to the endocrine system.

The pituitary gland secretes nine different hormones that either control other glands or directly regulate body processes. These hormones include adrenocorticotropic hormone (ACTH), which responds to stress and triggers the adrenal glands to release epinephrine; follicle-stimulating hormone (FSH), which triggers the production of sperm and the maturation of egg cells; and prolactin, which triggers the production of milk in females.

Other Glands

Other glands are located in the head or upper body, as shown in the diagram. The pineal gland secretes melatonin, which is involved in regulating body rhythms. The thyroid gland releases thyroxine, which regulates the process through which cells break down chemicals and produce energy. The parathyroid glands release hormones that help regulate the amount of calcium in the bloodstream. The thymus gland produces hormones that help the body fight disease.

Still other glands are located near the center of the body. The adrenal glands produce the hormone epinephrine, which causes the fight-or-flight response in your skeletal and heart muscles. The pancreas, which is also an organ of the digestive system, releases hormones called insulin and glucagon, which stimulate the liver to either take up or release sugar into the blood. Reproductive glands produce testosterone and estrogen hormones that control reproduction and the development of secondary sex characteristics.

The Reproductive System

The reproductive system is involved with sexual development and the production of offspring. Endocrine glands in the reproductive system produce sex hormones that are responsible for secondary sex characteristics in men and women. Sex hormones also contribute to the production of sex cells, or gametes. Female sex hormones regulate ovulation, the menstrual cycle, and pregnancy.

Testosterone and estrogen are the hormones mostly responsible for the physical differences between men and women. Testosterone is produced in male glands called testes and controls the development and function of the male reproductive system. It also controls male secondary sex characteristics, such as a deep voice and increased muscle mass. Estrogen is produced in female glands called ovaries and controls the development and function of the female reproductive system. It also controls female secondary sex characteristics, such as breast development.

Male Reproductive System

The male reproductive system includes, the testes, epididymis, scrotum, penis, urethra, and a variety of glands. The testes produce male gametes, called sperm and the hormone testosterone. Millions of sperm are produced each day and stored in the epididymis. The testes and epididymis are suspended in the scrotum, which is a sac that hangs outside the body. The position of the scrotum keeps sperm at a cooler temperature, so the sperm are able to mature. During sexual activity, the sperm travel toward the urethra, which is a tube that spans from the urinary bladder through the penis. A series of glands add fluids to the sperm to form semen. Semen leaves the body through the penis during ejaculation

Female Reproductive System

The female reproductive system includes the ovaries, fallopian tubes, uterus, and vagina. Female gametes, called eggs, are produced in the ovaries. The female reproduction system has several functions, including producing female sex hormones and storing and releasing the eggs.

The Menstrual Cycle

Every month, sexually mature women release an egg from one of their ovaries and shed their uterine lining. This process is referred to as the menstrual cycle. The cycle starts when an egg begins to mature inside a follicle in the ovary. The follicle produces estrogen, which causes the tissue that lines the uterus to thicken. In about 14 days, the egg is released from the follicle in a process called ovulation. The empty follicle continues to release estrogen and also begins to release another hormone, progesterone. These two hormones cause the uterine lining to grow even thicker. If the egg is not fertilized as it travels down the fallopian tube, it dies and disintegrates. The lining of the uterus breaks down and is shed through the vagina as menstrual blood. The cycle typically takes about 28 days and then begins again. If a mature egg and sperm unite, pregnancy results, and the menstrual cycle stops.

Fertilization

When an egg is fertilized by a sperm cell, it begins to divide. This ball of cells moves down the fallopian tube to the uterus and attaches itself to the uterine lining. Upon implantation, the ball of dividing cells is called an embryo. Some of the cells differentiate to form the placenta, which is an organ that allows nutrients and other materials to pass between the mother and the developing offspring. The embryo becomes a fetus eight weeks after fertilization. The fetus undergoes rapid development until about nine months into the pregnancy. At this point, the mother’s body produces hormones that cause labor. During labor, muscles in the uterus contract and relax, causing the baby to move down the birth canal until it is born.

Disruption of endocrine metabolism and dental pathology

A number of diseases are known in dentistry, the occurrence and development of which are closely related to the function of the endocrine glands.

The endocrine system directly affects the formation, development and functioning of the dentition.

Hormones affect almost all types of metabolism, due to the effect of hormones on the activity of enzymes.

Therefore, a systemic imbalance of the endocrine system plays an important role in the pathogenesis of oral diseases.

Knowledge of the clinical symptoms, features of the course of diseases of internal secretion in the oral cavity will allow timely diagnosis of the disease and, therefore, prevent the development of many complications: generalized periodontitis, caries, osteoporosis of bone tissue and other diseases that affect the quality of the dental system.

The pituitary gland has an extremely complex function; currently there are up to 22 different hormones secreted by the pituitary and hypothalamus. Pituitary dysfunction leads to various changes in the body, accompanied by the development of pathological phenomena in the dental system. In particular, it leads to a slowdown in the growth of the jaw bones, slows down the rate of teething, and also affects the development of enamel and dentin.

Diabetes mellitus is a chronic endocrinological disease characterized by high levels of sugar (glucose) in the blood.
Diseases of the oral cavity against the background of diabetes mellitus, according to the literature, are observed in most patients. Hyperglycemia of blood glucose levels during the day often leads to suppression of salivation and a feeling of dryness in the oral cavity.
Reduced salivation creates favorable conditions for an increase in the number of microorganisms, especially streptococci, staphylococci.
Patients with diabetes mellitus experience rapid and significant deposition of soft plaque and tartar.
Diabetes mellitus entails a violation of mineral metabolism, a decrease in the formation and activation of the destruction of bone tissue, which affect the state of the hard tissues of the tooth. In violation of mineral metabolism, calcium begins to be washed out of the body, and then fluorine. When calcium and fluorine are not enough, the enamel becomes fragile. Acid secreted by bacteria penetrates into it faster, which contributes to a more rapid course of caries.

Diabetes mellitus affects the condition of periodontal tissues, tk. vascular disorders develop in patients due to spastic changes in blood vessels and capillaries, as well as changes in the function of the blood itself.

Considering the hormonal system as a whole, one cannot but pay attention to the influence of the thyroid and parathyroid glands.
Thyroid hormone, thyrocalcitonin regulates the level of calcium in the body and, in turn, has a great influence on the process of calcification of enamel and dentin.

Hypothyroidism results from an underactive thyroid gland. Anemia, swelling and dryness of the oral mucosa are noted. The development of hypothyroidism can lead to enamel hypoplasia, hyposalivation, high intensity of caries lesions, and delayed teething.

The parathyroid glands produce parathyroid hormone, which is involved in the regulation of mineral, primarily calcium and phosphorus metabolism.

An important role in maintaining a normal level of calcium in the blood is played by vitamin D, which affects the intake of calcium from the intestines, stimulates the deposition of calcium in bone tissue.

The endocrine function of the gonads has a great influence on the growth and development of the body, in particular, the influence of sex hormones on the process of shaping the structures of the teeth, as well as on the state of the periodontal tissues, is being studied.

Steroid sex hormones such as estrogens, progesterone and testosterone are most associated with the occurrence, course and progression of periodontal disease, significantly affect protein and mineral metabolism in bone tissue.

You need to understand that the endocrine system does not tolerate careless handling and often gives rise to a number of related problems, therefore, the more timely access to specialists, the better the result.

Modern concepts of endocrine mechanisms of regulation of functions in health and disease | Fedorov

From December 1 to December 15, 1997, a conference with international participation “Endocrine mechanisms of regulation of functions in normal and pathological conditions” was held in the Academic City of the Novosibirsk Scientific Center, dedicated to the 75th anniversary of the birth of Professor Mikhail Grigoryevich Kolpakov (1922-1974).

The conference was organized by the Scientific Council for Physiological Sciences of the Russian Academy of Sciences and the institutions where MG Kolpakov worked – the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences and the Siberian Branch of the Russian Academy of Medical Sciences.

The conference was financially supported by the Russian Ministry of Science and Technology and the Russian Foundation for Basic Research (grant no. 97-04-58-058). 108 out of 171 announced reports of scientists from Russia, Ukraine, Belarus, Kazakhstan, Kyrgyzstan, USA, France, Sweden, Israel, Taiwan were presented at the conference.

Opening the conference, LN Ivanova, co-chair of the organizing committee, noted that the students of MG Kolpakov were the initiators of the conference. The conference was welcomed by Director of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences V. K. Shumny and Deputy Chairman of the Siberian Branch of the Russian Academy of Medical Sciences L. D. Sidorova.

The conference received greetings from the Director General of the Endocrinological Research Center of the Russian Academy of Medical Sciences I. I. Dedov, the editor-in-chief of the journal “Problems of Endocrinology” V. P. Fedotov, the director of the Institute of Experimental Endocrinology of the Russian Academy of Medical Sciences I. G. Akmaev, the chief endocrinologist of Kazakhstan M. E Zeltser, V. G. Shalyapina (St. Petersburg) and elders among physiologists studying the endocrine system, P. A. Wunder (Saratov).

The plenary session listened to the reports of MG Kolpakov’s friend and colleague, co-chairman of the organizing committee GS Yakobson (Novosibirsk) on the life path and scientific work of MG Kolpakov; student M. G. Kolpakov N. A. Kolchanova (Novosibirsk) about gene networks as a key object of molecular physiology; Yu. A. Pankova (Moscow) about genetically engineered producers of peptide hormones and proteins and their use in the diagnosis of endocrine pathology; AV Kamernitsky (Moscow) on chemical modifications of steroid hormone molecules that can become medicines; LE Panina (Novosibirsk) on the functional role of tetrahydro derivatives of steroid hormones. The plenary session ended with a report by MG Kolpakov’s daughter VM Chesnova (Los Angeles) on pituitary cytokines, which are factors in the paracrine regulation of pituitary function.

The remaining reports were divided into 8 sections. At the section “Adrenal reticular cortex and dehydroepiandrosterone”, the student of M. G. Kolpakov T. A. Obut (Novosibirsk) for the first time showed the role of this hormone in ensuring the body’s adaptation to chronic exposure and in preventing the development of stress-induced pathologies and raised the question of biological significance reticular cortex of the adrenal glands. In other submitted and announced reports, data were presented on the regulation of prolactinoma secretion of dehydroepiandrosterone (V.P. Babin, Novosibirsk) and its effect on steroidogenesis (L.E. Panin, Novosibirsk), the immune system (J. Cent, Taipei; L S. Eliseeva, Novosibirsk; A. V. Shurlygina, Novosibirsk), blood lipid composition (T. A. Filimonova, Maykop), hypertension syndrome (student of the Medical Institute E. T. Obut, Novosibirsk), as well as on the role of dehydroepiandrosterone and other neurosteroids in the function of the central and peripheral nervous system (E. E. Beaulieu, Paris) and on the state of the reticular zone of the adrenal cortex in rats with hereditary stress-induced arterial hypertension – the ISIAH line, see below (I. I. Buzueva , Novosibirsk).

The section “Hormonal regulation of functions and circadian rhythms” was opened by a joint report by M. G. Kolpakov’s student M. P. Moshkin (Novosibirsk) and J. Burn (Bethany, West Virginia) “Internal coordination of circadian rhythms and their role in the adaptive reactions of the organism “. A number of reports were devoted to circadian and seasonal rhythms in the endocrine system (L. A. Kolesnikova, a student of M. G. Kolpakov, O. V. Papa fi l o va, L. V. Shestopalova and M. S. Vinogradova; all from Novosibirsk), their nervous and hormonal regulation (K. S. Elbekyan and E. B. Arushanyan; both reports from Stavropol), their characteristics under stress (T. T. Podvigina, St. Petersburg; E. I. Juraeva, Tomsk; S. A. Khoreva, Minsk) and various diseases (Yu. S. Landyshev, Blagoveshchensk; Yu. O. Kim, Novosibirsk).

Other reports touched upon the biochemistry of the thyroid system (L. M. Polyakov, Novosibirsk), interhormonal interactions (A. G. Kartashev, Tomsk; S. S. Pertsov, Moscow; P. S. Demko, Kemerovo; R. G. Fedina, Novosibirsk; L. I. Shukshina, Moscow; student of M. G. Kolpakov and N. B. Pikovskaya, Novosibirsk). NI Tsirel’nikov (Novosibirsk) reported on the role of glucocorticosteroids in the expression of various forms of alkaline phosphomonoesterases.

The report of MG Kolpakov’s student VG Selyatitskaya (Novosibirsk) presents new data on the effect of glucocorticoid hormones on the activity of the organs of the lymphatic system at low temperatures. Some other reports were also devoted to the problem of the influence of environmental factors of a natural and anthropogenic nature on the endocrine system: students of M. G. Kolpakov N. A. Palchikova, S. V. . Odintsova, Yu. V. Lutova, D. G. Sakharova (all from Novosibirsk), O. V. Ermakova (Syktyvkar), O. O. Khizhnyak (Kharkov), I.S. Kolbay (Almaty), student of M.G. Kolpakov E.M. Kazin (Kemerovo).

At the section “Genetic aspects of hormonal regulation” MG Kolpakov’s student AL Markel (Novosibirsk) made a report on the genetic analysis of a line of rats he bred with hereditary spontaneous arterial hypertension induced by emotional stress (ISAH). Other reports of this section were devoted to the genetic control of the systemic organization of the hormonal activity of the hypothalamic-pituitary-testis complex (student of M. G. Kolpakov A. V. Osadchuk, Novosibirsk) and other genetic aspects of the endocrine function of the testes (T. V. Busygina, K. V. Svechnikov, both from Novosibirsk), the influence of selection for domestic behavior on the function of the hypothalamic-pituitary-adrenal system (V. S. Lankin, students of M. G. Kolpakov, I. N. Oskina and R. G. Gulevich; all from Novosibirsk) and the state of hormonal status, stress reactivity and reproduction in the water vole with a mutation (student of M. G. Kolpakov N. M. Bazhan, Novosibirsk), as well as genetic factors of disorders of steroidogenesis in the adrenal glands in the pathogenesis of polycystic ovaries (E R. Durinya n, Moscow).

At the section “Renin-angiotensin-aldosterone system and hormonal regulation of hemodynamics” student of M.G. Kolpakov V.I. to which researchers do not pay attention, but which are key in understanding the regulation of this system and its functioning, and dwelled in detail on his own studies of the interaction of the cholinergic and renin-angiotensin systems. OP Cherkasova (Novosibirsk) reported on the study of the activity of the angiotensin-forming system using a complex of fluorescent peptides by high performance liquid chromatography. SN Chumakov (Volgograd) presented a report on the role of atrial natriuretic peptide and endothelin in the neurohumoral regulation of blood circulation in healthy individuals and in patients with hypertension and chronic heart failure. NP Kazarinov (Novosibirsk) reported on the morphofunctional features of the glomeruli and juxtaglomerular apparatus of the kidney in ISIAH rats. The role of the renin-angiotensin-aldosterone system and its interaction with other endocrine systems in the regulation of water-salt balance in patients with borderline arterial hypertension is covered in the report of M. G. Kolpakov’s student N. B. Pikovskaya (Novosibirsk). N.P. Mertvetsov (Novosibirsk) reported on recombinant human angiogenin, obtained by genetic engineering, and showed its role in stimulating the growth of blood vessels.

Among the reports submitted for this section, it should be noted the reports of L. L. Branchevsky (Ivanovo) on the renin-angiotensin-aldosterone system as a mechanism for the conjugated functioning of the circulatory and excretory systems, V. N. Volkov (Moscow) on the features of determining and quantitative indicators of renin activity in human arteries and an increase in renin activity in alcohol intoxication as one of the causes of sudden cardiac death in persons with essential hypertension, V. A. Karlova (St. Petersburg) on ​​the features of neurohumoral regulation of hemodynamics in healthy individuals with hyper- and hypokinetic type of blood circulation and neurohumoral mechanisms of sodium metabolism dysregulation in borderline arterial hypertension, S. S. Golubeva (Irkutsk) on the peculiarities of the reaction of the adrenal cortex and periglomerular apparatus of the kidneys with various types of hyperosmolar loads in normo- and hypertensive animals and L. V. Kapilevich (Tomsk) on the involvement of the endothelium in the regulation of endothelium-1-induced contractile activity of rat aortic smooth muscles.

The section “Hormonal regulation of water-salt metabolism” opened with a detailed report by LN Ivanova (Novosibirsk) on the effect of vasopressin on the activity of hyaluronate hydrolases in the kidney of mammals and the bladder of amphibians. The physiological effects of vasopressin were discussed in 2 more reports among those submitted for this section: Yu. V. Natochin (St. Petersburg) presented a report on the role of autocoids in modulating the effect of vasopressin and the development of pathological processes in the kidney, N. I. Dmitrieva (St. Petersburg) — on the possible involvement of tyrosine kinases in vasopressin-stimulated ion transport and regulation of cell volume in frog skin.

General interest and lively discussion aroused the report of M. G. Kolpakov’s student N. S. Logvinenko (Novosibirsk-Stockholm) on a possible new way of aldosterone regulation of the function of Na ⁺ , K ⁺ -ATPase in the distal segments of rat kidney nephrons through membrane receptors with subsequent realization of the signal through calcium-dependent protein kinase C.

A poster presentation by A. V. Kamernitsky (Moscow) on chemical modifications of the aldosterone molecule, leading to the production of analogs with different conformations and on the features of their effect on electrolyte metabolism, had a great resonance .

A number of presentations and presentations were devoted to hormonal regulation of ion exchange in tissues under cooling conditions (student of M. G. Kolpakov A. F. Bazhenova, Ivanovo), under the influence of catecholamines (E. N. Borovets, Novosibirsk) and kidney function: effects of glucagon (V. D. Slepushkin, Novosibirsk), aldosterone (E. G. Rempel, Novosibirsk), oxytocin (V. B. Brin, Vladikavkaz; T. S. Sulakvelidze, Makhachkala), and also the influence of changes in the water and electrolyte balance: potassium load (A.D. Gerasev), hyperhydration in case of impaired innervation of the kidney (Ya.L. Muravyova) and the dynamics of ontogenesis (R.I. Aizman; all reports from Novosibirsk) on hormonal status organism and endocrine structures: renomedullary interstitial cells (B.N. Tsibel) and adrenal cortex (E.A. Minin; both from Irkutsk).

At the section “Hormones and pathology” the report of V. A. Tkachuk (Moscow) on the role of calcium-mobilizing hormones and the intracellular signaling caused by them in the pathogenesis of cardiovascular diseases and their treatment with calcium antagonists, which normalize increased reactions of vascular smooth muscle cells, aroused general interest for these hormones.

A number of reports were devoted to various endocrine aspects of ISIAH rats: ovarian function (student of M. G. Kolpakov M. G. Polyak, Rehovot, Israel), hypothalamic-pituitary-adrenocortical function (L. N. Maslova) and its differential sensitivity to different types of stress (G.V. Petrova), glucocorticoid and mineralocorticoid function of the adrenal glands in experimental myocardial infarction (A.R. Antonov) and their structure in early postnatal ontogenesis (I.I. Buzueva), catecholamines ( N.A. Makhanova; all reports from Novosibirsk) and rats genetically predisposed to catalepsy (N.I. Gryazeva, Novosibirsk). In addition, reports were presented and made on the state of the endocrine system in such human pathologies as hypertension (V. F. Ruban, St. Petersburg; V. N. Shvalev, Moscow), myocardial infarction and coronary heart disease ( A. A. Nikolaeva, A. D. Kuimov, Yu. O. Kim, all from Novosibirsk; I. L. Telkova, Tomsk), heart defects (G. A. Tsvetovskaya, A. N. Malagin, Novosibirsk), rheumatoid arthritis (I.E. Korochina, Orenburg), bronchial asthma (S.V. Naryshkina, Blagoveshchensk; M.N. Yakushenko and E. A. Kamyshova , Nalchik), osteogenic system (N. E. Kushlinsky, Moscow), obesity (E. O. Avershin, Novosibirsk; L. V. Suturina, Irkutsk), diabetes mellitus (E. A. Zhuk and N. E Barbashina, Novosibirsk; K. F. Vartanyan, L. V. Roslyakova, and T. V. Yakushina, Moscow; F. S. Dzugkoeva, Vladikavkaz; R. A. Kasymalieva, Almaty; A. A. Shishigin , Novokuznetsk; B.V. Romashevsky and S.A. Shestakova, St. Petersburg), autoimmune thyroid diseases (A.A. Breusov, Novosibirsk).

Among the announced reports, we should highlight the report by A. S. Kogan (Irkutsk) on the clinical implementation of the ideas of M. G. Kolpakov in the treatment of arterial hypertension, in

in which the author describes the results of a surgical operation of adrenal portalization, which contributes to an increase in the metabolism of aldosterone by the liver, leading to relief of hypertension.

The section “Physiological effects of steroid hormones” was opened by TV Babkina (Moscow), who raised a fundamentally new question that the catabolites of 5a-dihydrotestosterone Za-diol and 3p-diol in target cells of sex steroids can be considered as functioning hormones. In the report of V. M. Rzheznikov (Moscow), two areas of possible use of steroid nitrates are considered – as bioregulators of the reproductive and cardiovascular systems.

N. E. Ordyan and I. N. Zaichenko (both from St. Petersburg) reported changes in the level of steroid hormones in highly and low excitable rats under stress and sensitivity to social stress in rats born to females subjected to stress during time of pregnancy. Two more reports were devoted to the hormonal aspects of anxiety in rats: the corticosteroid system (A. Yu. Galeeva, St. Petersburg) and sex hormones (E. P. Vinogradova, St. Petersburg).

A student of M. G. Kolpakov, E. I. Solenov (Novosibirsk) reported on the interaction of native cytosolic complexes of the glucocorticoid receptor and synthetic oligonucleotides with direct and reverse sequences corresponding to the glucocorticoid-responsive element from the tyrosine aminotransferase gene promoter, and proposed a mechanism for DNA activation by a steroid hormone. A. A. Tinnikov (Novosibirsk) reported on the specific features of the binding of corticosteroids to specific proteins under the action of various stresses. A. Yu. Karyagina (Novosibirsk) reported on the protective role of glucocorticoids in the development of autoimmune hemolytic anemia in mice.

A number of reported and announced reports were devoted to the hormonal aspects of pregnancy and lactation: N.I. Tsirel’nikov (Novosibirsk-Stockholm), A.I. Tyumen), R. G. Fedina (Novosibirsk), M. 3. Tartakova, Kh. D. Dyusembin and Zh. A. Turebaeva (Almaty), L. F. Ad igamov (Moscow), S. B. Lu rie (Kemerovo).

2 poster presentations by V. I. Fedorov and O. aroused great interest. P. Cherkasova (Novosibirsk). In the first one, a commercially available microcolumn chromatograph of the new generation “Milichrome A-02” was demonstrated, with the help of which a mixture of corticosteroid hormones was separated. The stand presented a method for the analysis of individual amounts of steroid hormones in the extract of the adrenal cortex and blood serum with a lower sensitivity limit of 500 pg/ml. The second report was devoted to fundamentally new data on the asymmetry of the production of corticosteroid hormones in intact and stressed rats, which showed the individual contribution of each of the adrenal glands to the creation of an effective concentration of circulating corticosteroid hormones.

Of the announced reports, attention is drawn to the reports of a student of M. G. Kolpakov, L. V. Osadchuk (Novosibirsk) about fetal steroid hormones in silver-black foxes during domestication, V. N. Babichev (Moscow) about estrogen induction ovulatory release of luliberin and gonadotropins, L. F. Ad and Gamova (Moscow) on comparative studies of the mechanisms of hormonal activity of estradiol-17p and estrogenic compounds of the stilbene group, and A. N. Smirnova (Moscow) on the features of the interaction of 16a,17a-cycloalkane progesterone analogs with the rat uterine progesterone receptor.

The final section of the conference “Neuroendocrine regulation of functions” was opened by the report of L. P. Filaretova (St. Petersburg) on ​​the protective antiulcer effect of corticosteroids on the gastric mucosa under stress, proven by successive switching off of various parts of the hypothalamic-pituitary-adrenocortical system. GT Shishkina (Novosibirsk) examined the role of a2-adrenergic receptors in the hypothalamus in the regulation of the hypothalamic-pituitary-gonadal system. BN Manukhin (Moscow) presented the results of a computer experiment to elucidate the nature of the ligand-receptor interaction on models of the p-adrenergic receptor-specific blocker complex. D. A. Sibarov, a student of St. Petersburg State University, reported on the study of the role of oxytocin in the regulation of secretory processes in the pineal gland under stress. R. I. Kovalenko (St. Petersburg) reported on the features of changes in the functional activity of the oxytocin- and vasopressin-producing centers of the hypothalamus of muskrats and rats during apnea. L.D. Ephremo-va (Moscow) reported on the possibility of regulating the gonadotropic function of the pituitary gland with the neurotransmitter drug difenin, which reduces the hyperergic activity of the adrenergic structures of the brain. A.V.Amikisha (Novosibirsk) reported on the interaction of GABA-A receptors with the serotonergic system of the brain in the regulation of testosterone levels by a negative feedback mechanism. The state of p-adrenergic receptors of the cerebral cortex after an imbalance of glucocorticoids and androgens is considered in the report of N. Yu. Surnina. T. S. Kali did not report on the effect of prenatal increase in the level of glucocorticoids on the ontogeny of the catecholaminergic system of the rat brain (both reports from Novosibirsk).

Of the reported reports, attention is drawn to the reports of E. A. Rybnikova on the role of the neostriatum in the formation of afferent flows to neuroendocrine centers, E.D. Bazhanova on the age-related aspects of the regulation of the function of the adrenal cortex by peptide and monoamine hormones of the hypothalamus under stress and A.I. Bogdanov on the role of corticosteroids in stress-induced analgesia (all reports from St. Petersburg).

The session ended with a report by NN Dygalo (Novosibirsk) on the interaction of pre- and postsynaptic units of the noradrenergic system as components of an integral mechanism in neuroendocrine regulation.

Within the framework of the conference, a “round table” was held “Trends and prospects for the development of endocrine system research: contributions to physiology and pathology” (headed by V. A. Tkachuk and V. I. Fedorov). Opening the meeting of the “round table”, V. I. Fedorov noted that the conference showed the viability of the scientific school of M. G. Kolpakov, and drew the attention of the audience to the significant lag in practical medicine from the achievements of the physiology of the endocrine system.

VA Tkachuk began his speech with reverence for the Russian tradition of honoring the memory of his teachers, thanking the students of MG Kolpakov for organizing the conference. V. A. Tkachuk developed the question of the relationship between integrative and molecular aspects in the study of the endocrine system, presented a diagram of the hierarchy in the action of hormones and outlined the concept of a multiple mechanism for transmitting information up to the presence of receptors of opposite signs in each cell type.

Yu. A. Pankov focused the attention of the audience on the fact that a common property of all hormones is the regulation of gene expression, which puts molecular endocrinology in the category of the most developing sciences in the world, and suggested that in the 21st century it will stand out as an independent field of biology. Yu. A. Pankov outlined the likely paths for the development of endocrinology, based on the ratio of the current state of this field of knowledge in Russia and abroad.

Participants of the “round table” discussed the issue of revising the concept and term “hormone” in connection with new data on cytokines, auto- and paracrine systems, and the need for new methodological approaches to the analysis of hormones. A lively discussion unfolded after the main speeches, including the peculiarities of the domestic strategy for the development of the doctrine of the endocrine system. A peculiar result of the discussion was a remark by L. S. Eliseeva that each researcher follows an individual path.