Reaction of myeloid tissue cells and change in the extracellular skin matrix under conditions of simulated physical activity

Myeloid tissue cells participate in maintaining functional state of the microvasculature, local blood flow and influence the proliferative activity of fibroblasts. Objective. To evaluate the reaction of mast cells (MCs), distribution of fibroblasts and collagen fibers under conditions of simulated physical activity of varying degrees. Material and methods. The experiments were carried out on male rats, which were subjected to physical activity of different intensity (10 swimming sessions). Skin samples (1×1 cm) were taken from dorsal surface of the neck, paraffin blocks were prepared and stained with hematoxylin and eosin, toluidine blue, indigo carmine. Results. There were no significant changes in light physical activity. An increase in the number of MCs and fibroblasts in the dermis has been noted, as well as strong correlation interactions between the distribution density of fibroblasts, collagen fibers and MCs have been in medium physical activity (r=0.9; p<0.05). The MCs population decreased and mast cell degranulation index increased in severe physical activity. Correlation interactions were moderate between distribution density of fibroblasts, collagen fibers and MCs (r=0.6; p<0.05). Conclusion. Reaction of MCs in the dermis during medium physical load was accompanied by an increase in MCs number, change of morphofunctional activity as well as an increase in the proportion of fibroblasts and collagen fibers in the dermis. There was a decrease in the proportion of MCs, fibroblasts and collagen fibers distribution, increase in the mast cell degranulation index in severe physical activity.