MAST CELLS OF THE LUNGS DURING EXPERIMENTAL EXPOSURE TO GLYCERIN-PROPYLENE GLYCOL SMOKING MIXTURE

Recently, in addition to traditional nicotine-containing smoking mixtures such as tobacco products or cigarettes, alternative smoking methods based on heating a special liquid, vape, containing glycerin and propylene glycol, have become popular. The effect of smoking vaping mixtures on the lungs, to date, remains unexplored. It is possible that mast cells are involved in the pathogenesis of these processes, as an essential component of the microenvironment of the respiratory tract. The aim of the work was to study the effect of glycerin-propylene glycol smoking mixture on rat lung mast cells. The experiment was conducted on Wistar rats. The animals were placed in an inhalation chamber, where the rats were exposed daily for 1 hour for 3 months to: nicotine–containing smoking mixture (control), smoking mixture for vaping (experimental group); comparison group - intact rats. Histological methods were used to assess the general condition of the lung tissue, and mast cells were detected using toluidine blue, followed by their typing. The degranulation coefficient and the average histochemical coefficient were calculated. Statistical processing was performed using the Mann-Whitney criterion (* – at p <0.05 – the differences are significant). The experiment showed that after 3 months of exposure, pathological changes are observed in the lungs: fibrosis of the bronchial walls, lymphocytic-leukocytic infiltrations, bull formation, and a vascular sludge phenomenon. Exposure to both nicotine-containing and glycerin-propylene glycol smoking mixtures causes unidirectional changes in the respiratory tract, which are expressed in the development of inflammatory processes and tissue remodeling. When exposed to smoking mixtures, mast cells in the lungs are irregularly shaped, elongated or fusiform. The mast cell population in the lungs reacts by increasing functional activity, regardless of the composition of the smoking mixture. Prolonged exposure to a glycerin-propylene glycol smoking mixture leads to an increase in the total number of mast cells, which is regarded as a long-term measure by the microenvironment, indicating a more significant negative effect of this smoking mixture.