Морфогенез ателектазов легких при экспериментальном радиоиндуцированном воздействии

Abstract

Introduction. Pulmonary atelectasis that occur in the chest organs exposed to radiation is often accompanied by the development of radiation alveolitis, fibrosis, and respiratory failure. Different forms of alveolitis cause severe disturbance of the structure of alveolocytes. However, the effect of radiation on the vascular compartment of pulmonary tissue, bronchioles and alveolocytes, and intercellular structures in the formation of atelectasis was not studied in detail. The importance of quantitative and qualitative changes in pulmonary surfactant (PS) in the development of atelectasis was understudied. The aim of the work was to explore the development of pulmonary atelectasis in rats after radiation exposure. Materials and methods. The study was carried out on 60 male Wistar rats aged 8-9 weeks, body weight 200-220 g. Single local irradiation of animals under Nembutal anesthesia (40 mg / kg weight) was carried out by the RUM-17 apparatus (voltage 200 kV, current 15 mA, filters 0.5 mm Cu + 1.0 mm Al, skin-focal length 25 cm) at a dose of 12 Gy. Phospholipids (PL) in pulmonary surfactant were quantitatively determined in lavage fluid extracted from the rat lung. The material was examined histologically (hematoxylin and eosin, alcian blue, picrofuchsin according to Van Gieson) and under transmission electron microscope. The thickness of the epithelial lining of bronchioles, the average diameter of the nuclei of epithelial cells of bronchioles and the thickness of the interalveolar partitions were calculated morphometrically on control samples at different time periods after exposure to ionizing radiation. Results. Atelectasis occurred at the early stages of the experiment is surfactant-dependent, which is confirmed by the decreased amount of PS and PL in lavage fluid. The formation of atelectasis in later periods is caused by the obturation, narrowing of the lumen of the bronchi and bronchioles due to thickening of the epithelial lining and pronounced bronchial bronchoconstriction. Conclusion. Understanding the mechanisms of development of atelectasis is necessary in order to prevent the pathology described above and reduce the risk of complications. Keywords: atelectasis, distelectasis, morphometry, radiation fibrosis, radiation alveolitis