Endocrine diseases

In recent years, modern endocrinology has made significant progress in understanding the diverse effects of hormones on the body's vital processes. A special role is given to the endocrine system in the mechanisms of reproduction, information exchange, and immunological control. The structural and organizational period of the body is also closely related to endocrine factors. For example, a deficiency of androgens during the period of brain development in men can be the cause of its female organization, the emergence of homosexuality. An excess of these hormones in women in the phase of brain differentiation leads to its male organization, which can cause acyclic secretion of gonadotropins, behavioral characteristics of the body.

The scope of clinical endocrinology has expanded significantly. Endocrine diseases are being identified, the genesis of which is associated with dysfunction or interaction of various systems and organs. A number of endocrine syndromes have become known, in which the primary link in pathogenesis is associated with damage to the gastrointestinal tract, dysfunction of the liver or other internal organs. It is known that cancer cells in tumors of the lungs, liver and other organs can secrete adrenocorticotropic hormone (ACTH), beta-endorphins, growth hormone, vasopressin and other hormonally active compounds, which leads to the development of endocrine syndromes, similar in clinical manifestations to pathology of the endocrine glands.

The pathogenesis of endocrine diseases is based on disturbances in complex interactions of the endocrine, nervous and immunological systems against a certain genetic background. Endocrine diseases can arise as a result of primary damage to the function of the endocrine gland, disorder of regulation of secretion and metabolism of hormones, as well as a defect in the mechanism of action of hormones. Clinical forms of endocrine diseases have been identified in which disturbances in hormone-receptor interaction are the cause of the pathology.

Primary lesion of the endocrine glands function

The endocrine system is a chemical system that regulates the activity of individual cells and organs. Hormones secreted into the blood contact virtually any cell in the body, but act only on target cells that have a genetically determined ability to recognize individual chemical substances using appropriate receptors. Nervous regulation is of particular importance when a physiological function needs to change very quickly, for example, to initiate and coordinate voluntary movements. Hormones, on the other hand, apparently better meet the need for long-term adaptation to environmental conditions, maintaining homeostasis, and implementing the genetic program of various cells. This division of the two systems is quite relative, since more and more data is accumulating on their interaction in regulating individual physiological processes. This places special demands on the definition of the term "hormone," which currently unites substances secreted by endocrine cells under the influence of specific signals and that usually have a distant effect on the function and metabolism of other cells. A characteristic property of hormones is their high biological activity. Physiological concentrations of most of them in the blood fluctuate within the range of 10 ^-7 -10 ^-12 M. The specificity of hormonal effects is determined by the presence of discriminator proteins in cells that are capable of recognizing and binding only a certain hormone or substances close to it. Any function of cells and the body is regulated by a complex of hormones, although the main role belongs to one of them.

Hormones are most often classified by chemical structure or by the glands that produce them (pituitary, corticosteroid, sex, etc.). The third approach to classifying hormones is based on their function (hormones that regulate water-electrolyte balance, glycemia, etc.). According to this principle, hormonal systems (or subsystems) are distinguished, including compounds of different chemical nature.

Endocrine diseases can be determined by a deficiency or excess of a particular hormone. Hyposecretion of hormones can depend on genetic (congenital absence of the enzyme involved in the synthesis of a given hormone), dietary (for example, hypothyroidism due to iodine deficiency in the diet), toxic (necrosis of the adrenal cortex under the influence of insecticide derivatives), immunological (the appearance of antibodies that destroy a particular gland). Thus, in type I diabetes mellitus, there is a violation of cell-mediated and humoral immunity, the manifestation of which is the presence of immune complexes in the blood. HLA DR antigens were found on thyroid cells of patients with diffuse toxic goiter and Hashimoto's thyroiditis. They are absent in the norm, their expression was induced by leucine and γ-interferon. DR antigens were also found on beta cells in type II diabetes mellitus.

In some cases, hyposecretion of hormones is iatrogenic, i.e. caused by the actions of the doctor (for example, hypoparathyroidism due to thyroidectomy for goiter). The most general principle of treating hyposecretion of hormones is hormone replacement therapy (administration of the missing hormone from the outside). It is important to take into account the species specificity of the administered hormone. In the optimal variant, the scheme of administration and doses of the hormone should imitate its endogenous secretion. It is necessary to remember that the introduction of the hormone leads to the suppression of the residual endogenous secretion of its own hormone, therefore, abrupt cancellation of hormone replacement therapy completely deprives the body of this hormone. A special type of hormone replacement therapy consists of transplantation of endocrine glands or their fragments.

Infections, tumors, tuberculosis can lead to a decrease in hormone secretion. When the cause of the disease is unclear, they speak of an idiopathic form of endocrine disease.

Among the causes of hormone hypersecretion, the first place is occupied by hormonally active tumors (acromegaly in pituitary tumors), as well as autoimmune processes (thyroid-stimulating autoantibodies in thyrotoxicosis). The clinical picture of hormonal hypersecretion can also be caused by taking hormones for therapeutic purposes.

Hypersecretion is treated with surgical methods, as well as agents that block the synthesis, secretion or peripheral action of hormones - antihormones. The latter themselves have virtually no hormonal activity, but prevent the hormone from binding to the receptor, taking its place (for example, adrenergic blockers). Antihormones should not be confused with antagonist hormones. In the first case, we are usually talking about synthetic drugs, while in the second case we mean natural substances that have their own hormonal activity, but produce the opposite effect (for example, insulin and adrenaline have the opposite effect on lipolysis). Being antagonists in relation to one function, the same hormones can be synergists in relation to another.

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