A MORPHOMETRIC ANALYSIS OF LUNG COMPONENTS IN WHITE RATS WITH HYPOXIA COMBINED WITH THE NATURAL GAS IMPACT

Abstract

The human respiratory system is daily exposed to various biotic and abiotic factors, and, first of all, there is damage to the cellular elements of the mucous membrane. Prolonged irritating effects are accompanied by inhibition of regenerative processes and subsequent morphofunctional restructuring of the structural components of the lungs. The aim of the study was to research the morphometric parameters of the structural components of the lungs of white laboratory rats at different periods of chronic simulated hypoxia combined with inhalation of natural gas from the Astrakhan field, at a concentration of 3 mg/m3. The study covered 94 white mongrel sexually mature male rats who were in conditions of chronic hypoxia combined with natural gas inhalation for 120 days. The animals were placed in a special seed chamber produced by the Erisman Institute with a volume of 200 liters with a variable composition of the air-gas mixture, and with a decrease in the oxygen concentration in the inhaled air to 17.5 %, natural gas from the Astrakhan field was supplied through a special nozzle. The animals were kept in experimental conditions lasting four hours a day for five days a week. For the manufacture of histological preparations, animals were anesthetized with sodium ethaminal (40 mg/kg weight). Lung tissue samples were fixed in a 10 % solution of buffered formalin. The preparations were stained with hematoxylineosin and Van Gison. The analysis and visualization of the obtained glass preparations was carried out using a ZeissAxioScopeA1 light microscope (Germany) and a LeicaAperioCS2 digital scanner of micropreparations with specialized software. It was determined that the initial significant changes were already formed by 60 days of experimental exposure. In one group of drugs, thickening of the interalveolar septa associated with the processes of edema formation and infiltration by cellular elements were noted, another group of drugs showed emphysemalike changes with stretched and partially torn alveoli. By day 90 of the experiment, a decrease in the airiness of the lung tissue was determined on all preparations, manifested by thickening of the interalveolar septa and a decrease in the diameter of the alveoli. By day 120, the changes identified in the early stages were progressively increasing: there were areas completely devoid of alveoli, other fields of vision showed alveoli with torn walls. On the part of the bronchi, the following pattern was determined: an increased thickness of the walls of the bronchi, mainly due to the mucous and adventitial membranes, followed by deformation of the bronchi of medium and small caliber and the formation of peribronchial infiltrates. The morphometric analysis confirmed that chronic hypoxia combined with natural gas inhalation causes significant changes in the structural components of the lungs.