Background: In recent years, attention of the scientific community has been drawn to the
study of the role of homocysteine in the pathology of diseases in general and the respiratory system
in particular. Violations of the synthesis and disposal of homocysteine are the cause of its excessive
accumulation in the body, which subsequently leads to damage to all organs and systems.
Methods: We conducted this study on 64 white non-linear rats of 6-8 and 24-26 months old rats,
which were divided into two control and experimental groups during the experiment. The study of
ultrastructural changes in the lungs of rats was performed using an electron microscope.
Results: The results of the conducted study show that all the animals of the experimental group, corresponding
to 32 (50%) cases, possess conspicuous morphological changes in the structure of the
The specific features of mature animals were the narrowing of the alveolar space of the part of the
alveoli and the increase in the number of macrophages in them. Partial desquamation of capillary
endothelial lining and a slight increase of collagen fibers in interalveolar membranes were observed
compared to control animals. A characteristic feature for older animals was the growth of connective
tissue, predominantly collagen fibers, which led to pneumosclerosis. The thickening of the aerogemic
barrier was also detected, and the endothelial lining was intermittent or desquamated.
Conclusion: Mature animals of the experimental group were characterized by activation of
inflammatory processes, oxidative stress, due to increased production of macrophages and, as a
consequence, the launch of the humorous link of immunity, while in old rats were determined by
fibrosis, disorders of the trophic and gas metabolism, as well as damage to the endothelium part of