Under conditions of hypoxia, a change in the morphological and functional state of the components of the microvasculature bed will be accompanied by a change in the adequacy and usefulness of the immune response and hematopoiesis. The purpose of the study was to determine the morphofunctional state of the vascular component of the red bone marrow and spleen at various times of simulated hypoxia and to identify the degree of influence of CD68-positive cells on this state. Chronic hypoxia was modeled on 246 outbred male rats using special chambers containing natural gas from the Astrakhan gas field (Russia) at a concentration not exceeding the maximum allowable. The experiment was continued for 120 days, inhalation was carried out five days a week for four hours a day, the removal of animals from the experiment was carried out every 30 days. The functional activity of the vascular component of the red bone marrow was determined using the method of laser Doppler flowmetry. The degree of expression of inducible (iNOS) and endothelial (eNOS) NO synthases and the distribution of CD68-positive cells in the spleen structures were determined by immunohistochemical method. The study showed that as the duration of chronic simulated hypoxia increases, there is a decrease in the microcirculation index, an increase in myogenic tone and shunting index, which, taken together, indicates a deterioration of organ perfusion and confirms the formation of a hypoxic state. An analysis of the functional activity, carried out using an immunohistochemical study of the expression of iNOS and eNOS in the structures of the spleen, showed that as the duration of the experiment increased, the level of endothelial synthase decreased and the level of inducible synthase increased. Perhaps this is due to the influence of biologically active substances secreted by macrophages activated during hypoxia. This is supported by an increase in the presence of CD68-positive cells in the red pulp and along the connective tissue trabeculae as the experimental exposure increases.
The aim of research was to study the distribution of mast cell populations in the lungs and spleen depending on their expression of proteases in normal conditions and different periods of simulated hypoxic hypoxia.Material and methods. Hypoxic hypoxia was modeled on 87 outbred male rats using 200 liter chambers. The animals were under experimental conditions for four months. Rats were removed from the experiment after 30, 60, 90 and 120 days. After the animals were removed from the experiment, the lungs and the spleen were removed and fixed in 10% neutral buffer solution of Labiko formalin. Lung and spleen preparations were stained with hematoxylin and eosin and according to Van Gieson. For immunohistochemical studies, a panel of monoclonal antibodies was used: Anti-Mast Cell Tryptase antibody, Anti-Mast Cell Chymase antibody.Results. When modeling hypoxia in the structures of the lungs at the terms of 30 and 60 days, the content of predominantly tryptase-positive cells increased, and by the 90th and 120th days, the content of chymase-positive cells increased. By the end of the experimental exposure, the number of tryptase-positive cells increased by 3 times, and chymase-positive – by 7,7 times compared with the control. As the duration of the experiment increased, the presence of tryptase-positive cells in the spleen increased by 3,5 times, chymase-positive cells – by 7 times in the structures of the red and white pulp.Conclusion. During the formation of chronic hypoxic hypoxia in the body of laboratory animals, there is a redistribution of mast cells expressing tryptase and chymase. The most significant increase in the number of chymase-positive mast cells was noted both in the lungs and in the spleen.
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