ROLE OF BIOLOGICAL MODELING OF RESPIRATORY DISEASES IN COVID-19 CONDITIONS: HISTOLOGICAL PICTURE OF HEALTHY AND STRESS-INDUCED LUNGS
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the 2019 coronavirus disease (COVID-19), has reached a pandemic level. Currently, there is abundant evidence that COVID-19 coronavirus can seriously affect the heart, blood vessels, nerves, brain, kidneys, and skin. Of course, the lungs and respiratory tract are the focus of attention for COVID-19 respiratory disease. This article assesses the parameters of pulmonary circulation in the dynamics of the respiratory cycle phases during spontaneous respiration in intact animals, and describes the histological picture of the lung tissue of intact rats. Pulmonary circulation and respiratory patterns were studied using the method of recording reopulmonography in rats. Taking into account the fact that stress factors usually act on the body in combination, in experiments on rats with hematoxylin and eosin staining of lung tissue, functional changes in pulmonary circulation and the histological picture of the lungs under the combined effects of immobilization and hypothermia were studied. It was found that disorders occurring at the level of microcirculatory vessels of the lung tissue are accompanied by a decrease in blood filling, the development of signs of arteriol spasm, an increase in blood filling of capillaries and postcapillary venules with a steady increase in the permeability of the vascular wall.