The role of nonspecific proteolysis in the development of alterative changes in lung tissue when using electronic cigarettes

In recent years, the number of electronic cigarettes (ES) users has been growing steadily around the world. ES heat and vaporize components of a mixture of propylene glycol, vegetable glycerin, nicotine, and flavors. Reports of severe forms of lung injury caused by the use of ES, some of which have resulted in death, urge studying the pathogenetic mechanisms of such complications. One of the mechanisms is the activation of nonspecific proteolysis accompanied by the destruction of connective tissue components of the blood-air barrier.

Aim of the study. To study the dynamics of the proteinase-inhibitor system indicators and its role in the morphological changes of lung tissue in experimental modeling of the effects of ES.

Methods. Experimental studies were performed in 24 white male Wistar rats weighing 160 – 180 g. ES use of was simulated by intermittent exposure to smoke mixture vapors using a POD system connected to a two-channel compressor.

Results. Analysis of the state of the nonspecific proteinase inhibitory system in rat broncho-alveolar lavage and blood serum and the results of morphological studies indicate activation of trypsin-like proteinases and depletion of the local antitryptic potential, leading to biochemical changes with subsequent structural changes in lung tissue. The latter are characterized by congestion, leukocyte infiltration, and stromal proliferation. In addition, exposure to nicotine-containing mixtures has been shown to affect the proteinase inhibitory system and blood serum composition, which is associated with a compensatory increase in antitrypsin activity.

Conclusion. The results of the study indicate the activation of trypsin-like proteinases in broncho-alveolar lavage, which have a damaging effect on lung tissue, leading to disturbances in tissue hemodynamics, extravasation of leukocytes, remodeling and thickening of the blood-air barrier.

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