Mast cells are an important link in the immune system. They are involved in many pathological processes such as stress, inflammation, autoimmune processes and carcinogenesis. The purpose of the review is to summarize the data on the role of mast cells in carcinogenesis. Materials and methods. Review of available literature sources published in Elibrary and PubMed. Results. Tumor growth in the body is accompanied by immune system dysfunction and mast cell response. Mast cells are able to stimulate tumour growth through the secretion of proteases, angiogenic and growth factors, and at the same time have a tumour suppressive effect. The response of the mast cell population depends on the type of tissue from which the tumor is developing, the speed and stage of the process, the localization of the mast cells, and the combination of pro- and anti-tumor factors. During tumour development and growth, total degranulation of mast cells occurs. In addition, mast cells in normal and tumor tissue differ in structure. This article provides information on the role of mast cells in carcinogenesis. Conclusion. Thus, mast cells on the one hand positively affect tumor growth through the synthesis of proteases, growth and angiogenic factors, and on the other hand, act as inhibitors of malignant growth. The response of mastocytes directly depends on the tissue in which tumour develops, on its type and degree of malignancy, the stage of pathological process, localization of mast cells and the degree of their activation, as well as the total balance of pro- and antitumour effects.
Цель -изучить влияние экспериментального рака молочной железы и стресса на состояние тимуса лабораторных животных.Материал и методы. С помощью люминесцентно-гистохимических, общегистологических и иммуногистохимических методов исследован тимус 40 белых нелинейных крыс-самок одного возраста. Животные были разделены на 3 группы. В 1-й группе находились интактные особи. Крысам 2-й группы вводили N-метил-N-нитрозомочевину, вызывающую рак молочной железы. Животные 3-й группы испытывали сочетанное воздействие канцерогена и водно-иммобилизационного стресса.Результаты. Установлено, что введение крысам-самкам N-метил-N-нитрозомочевины вызывает увеличение размеров мозгового и коркового вещества долек тимуса. В клетках премедуллярной и субкапсулярной зон отмечается повышение уровня серотонина и катехоламинов, а в клетках премедуллярной зоны, тимоцитах коркового и мозгового вещества -снижение уровня гистамина. Уменьшается соотношение (серотонин+гистамин)/катехоламины, процентное содержания дегранулированных форм тучных клеток возрастает. Также увеличивается количество зрелых Т-лимфоцитов и макрофагов на фоне уменьшения численности S-100 + клеток. При сочетанном воздействии факторов выявлено уменьшение размеров долек органа, замещение паренхимы жировой и соединительной тканью, повышение содержания серотонина и катехоламинов, и значительное снижение уровня гистамина, с падением соотношения (серото-нин+гистамин)/катехоламины в тех же клетках, увеличение зрелых форм Т-лимфоцитов и макрофагов, а также уменьшение процентного содержания дендритных клеток.Заключение. Сочетанное воздействие вызывает более выраженную дезорганизацию морфофункционального состояния тимуса и приводит к формированию 4-й фазы акцидентальной инволюции тимуса с развитием атрофии и склероза органа.Ключевые слова: тимус, стресс, канцерогенез, акцидентальная инволюция тимуса, биогенные амины, тучные клетки, дендритные клетки, лимфоциты, макрофаги. Cellular Composition of Rat Thymus with Combined Effects of Carcinogen and StressThe aim of the research was study the effects of experimental breast cancer and stress on the thymus of laboratory animals Material and methods. Thymus 40 white nonlinear female rats of the same age were investigated using luminescent-histochemical, general histological and immunohistochemical methods . The animals were divided into 3 groups. In the 1 st group were intact animals. Rats of the 2 nd group were injected with N-methyl-Nnitrosourea, causing breast cancer. Animals of the 3 rd group experienced a combined effect of carcinogen and water-immobilization stress.Results. It was established that the administration of N-methyl-N-nitrosourea to female rats causes an increase in the size of the medullar and cortex of the thymus lobes. In cells of the premedullary and subcapsular zones, an increase in the level of serotonin and catecholamines is observed, and in cells of the premedullary zone, in the thymocytes of the cortex and medulla -a decrease in the level of histamine. The ratio (serotonin + histamine) / catecholamines decreases and t...
The adrenal gland is one of the first organs to respond to external influences. Cortisol, with its important properties affecting the immune system, proliferation and apoptosis in various tissues, is a significant indicator of such a pathological process as malignant growth. Selenium is a powerful antioxidant having an immunomodulatory action and exhibiting anticarcinogenic effects. In this paper, we investigate adrenal morphofunctional changes under experimental carcinogenesis against the background of urethane and selenium administration by determining blood cortisol concentrations and studying the aggregate morphometric index of adrenal glands. The study revealed that carcinogen introduction imitates the adaptation syndrome stages in the organism and is accompanied by changes in the cortisol level and aggregate morphometric index. Maximal values of the studied parameters were detected after 1 month of exposure to carcinogen, which indicated the development of the alarm phase. A further decrease in the indices after 2 and 3 months down to the intact level indicates the development of the resistance stage. A sharp decrease in the indices after 6 months shows the exhaustion stage. An isolated course introduction of selenium leads to a reliable decrease in the aggregate morphometric index practically in all terms that indicates the stress-relieving influence of the microelement. The combined effects of selenium and carcinogen revealed a dropout of the alarm stage, but rapid elimination of the micronutrient from the body could not prevent the development of the exhaustion phase after 6 months.
Micro- and macroelements play a significant role in the unimpaired functioning of all organs and systems. Important essential trace elements include selenium, which plays a crucial role in many physiological processes, including immune responses. The purpose is to generalize available data on the effect of selenium on the functioning of various organs and systems of the human body. Materials and methods. This literature review presents data on the effect of selenium on the body, published in domestic and foreign literature sources. Results. Selenium belongs to essential trace elements; it is a part of various proteins and enzymes that have cytoprotective, antitumor, antimutagenic effects. In addition, selenium participates in the functioning of the body's endocrine, reproductive, immune and antioxidant systems, although it was previously considered one of the most toxic trace elements. Many studies have been devoted to the analysis of selenium's effect on the processes of carcinogenesis and prevention of the development of tumor processes of various localization. Selenium-containing enzymes play one of the leading roles in anti-carcinogenic action, as they take part in the antioxidant defense of the body, regulate apoptosis and cell proliferation, protect desoxyribonucleic acid from damage, affect the metabolism and detoxification of carcinogens. Conclusions. The study of selenium's antitumor effect is of the greatest interest at present, since the number of patients with oncopathology is increasing every year.
Oncopathology is one of the main mortality causes in the population. The immediate cause of death in a patient with cancer is metastatic spreading. The study of this pathological process is difficult due to asymptomatic course of the metastatic process, non-specificity of the main clinical analyses, impossibility of in-life studying the process of metastatic spreading. For this reason, laboratory models of metastatic spreading are being investigated, which can be connected both with direct introduction of tumor strains into the organ and with the development of metastases during experimental carcinogenesis. The issue of studying the endocrine system and its influence on the processes of metastatic spreading remains relevant. One of the organs that react to changes in the internal environment is the adrenal glands. The adrenal cortex plays an important role in the body's homeostasis, controlling the amount of cortisol, aldosterone and sex hormones (androgens and a small amount of estrogens), while the adrenal medulla controls stress reactions by discharging adrenaline and norepinephrine. Each of the hormones synthesized by the adrenal glands is somehow involved in the processes of carcinogenesis and metastatic spreading. Thus, cortisol, one of the hormones formed in the adrenal cortex, has a pronounced immunosuppressive effect, it affects the rate of cell proliferation, angiogenesis, differentiation and apoptosis, has a destructive effect on connective tissue. An increase in catecholamines in the blood leads to the damage to biological membranes, which stimulates adhesion and extravasation of tumor cells. In addition, catecholamines stimulate lymphoproliferation. Sex hormones affect not only hormone-dependent tumors of the reproductive system by stimulating cell growth, enhancing uncontrolled cell proliferation and angiogenesis, but tumors of other organs as well. Aldosterone, acting on the vascular wall, promotes the penetration of tumor cells into the vascular bed and their spread throughout the body.
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