Dynamics of morphological manifestations of the experimental acute aspiration bronchopneumonia development.

Abstract

Background. Currently, there is a need to create an experimental model for reproducing the main pathogenetic mechanisms of COVID-associated lungs damage. The first stage of such a model may be reproducing acute aspiration bronchopneumonia in rats. Objective. Examine the dynamics of morphological changes in the lungs in the development of experimental acute aspiration bronchopneumonia. Methods. The group of laboratory Wistar rats (n=25) in compliance with bioethical norms under typoental anesthesia was carried out operational intervention with the introduction of a sterile capron thread 2.5 cm long and a thickness of 0.2 mm to a depth of 2.5 cm. In the control group included 5 false-controlled animals. At 7, 14, 21, 28 and 56 days, the animals were derived from the experiment, morphological studies were carried out with the painting serial sections with hematoxylin-eosin. Results. On the 7 day, the morphological picture testified to the development of the acute stage of exudative inflammation with the full-blood of vessels, microtrombosis, dyslectasis, hyperplasia of alveolocytes II type. After 14 days, the proliferative stage was formed with alveolocytes hyperplasia, the epithelium of bronchi, as well as fibroblasts with the formation of sharp peribronchial and alveolar abscesses. After 21 days, the development of the lungs fibrosis with the organization of acute peribronchial and alveolar abscesses was noted, peribronchial and intraalveoli pronounced interstitial edema and the reactive hyperplasia of lymphoid follicles of a mixed nature. After 28 days, bronchopneumonia was organized in the form of fibrosis parenchyma, sections of chronic productive inflammation with the formation of resorbative granuloms; sections of the blood vessels hyalinose. For 56 days, these phenomena were progressed before the development of dense fibrosis (carnification) with sections of chronic abscesses with a formed by a connective tissue capsule, the development of vascular hyalinose. Conclusion. Thus, the model of acute aspiration bronchopneumonia reproduces the dynamics of morphological manifestations of acute lung damage, which is the basis for the development of pathogenetic therapy fields.