SUMMARY
Introduction. Despite significant scientific advances in the understanding of the clinical and pathobiochemical aspects of acute respiratory distress syndrome (ARDS), there is no specific therapy. This substantiates the search for new mechanisms of the impact of damaging factors on pulmonary tissue and the body of patients with ARDS.The aim of the study – to analyze the chemical composition of the pulmonary surfactant in the dynamics of acute respiratory distress syndrome in rats.Research Methods. Experiments were conducted on 60 white nonlinear male-rats, which were modulated acute lung injury by intratracheal administration of hydrochloric acid at pH 1.2 at a dose of 1.0 ml/ kg per breath.The content of phospholipids, triacylglycerols, free fatty acids and cholesterol was determined in the pulmonary tissue homogenate. The biochemical study of surfactant phospholipids was performed by thin layer chromatography.Results and Discussion. The results of the study indicate an increase of cholesterol and free fatty acids concentration in the pulmonary homogenate in the dynamics of ARDS. In contrast to the content of cholesterol and free fatty acids in the tissues of the lungs, the concentration of triacylglycerols and phospholipids are decreased. The obtained data indicate that the chemical structure of the surfactant is violated by ARDS, which leads to the decreasingof its functional capacity. Against the background of a marked reduction in the content of phosphatidylcholine, an increase in lysophosphatidylcholine, the percentage of phosphatidylethanolamine, sphingomyelin, phosphatidylinositol and phosphatidylserine increased in a compensatory manner. It should be noted that these values reached their maximum value in 5 research groups, in particular, after 24 hours, the content of phosphatidylethanolamine was higher by 48.4% vs control indicators, respectively, sphingomyelin – by 22.0%, phosphatidylinositol – by 37, 7% and phosphatidylserine – by 35.0%.Conclusions. In case of acute respiratory distress syndrome in rats, the chemical structure of surfactant is altered due to changes in lipid metabolism: cholesterol and free fatty acids had increased, levels of triacylglycerols and total phospholipids had decreased in pulmonary homogenate in the dynamics of the studied pathology. The obtained data indicate a decrease in the surfactant synthesizing capacity of the lungs with respiratory distress syndrome.