ULTRASTRUCTURAL CHANGES IN RATS SKIN SEBOCYTES DURING EXPERIMENTAL CHRONODESTRUCTION

Abstract

Purpose of the study ultrastructural changes in rat skin sebocytes during experimental chronodestruction. In the experiments, 22 white outbred male rats with a body weight of 170-220 g were used. The experimental animals, in accordance with the experimental design, were randomly divided into 3 groups: group 1 - intact (n = 8) - animals under standard fixed conditions lighting (12 hours light/12 hours dark); group 2 (n=8) – animals with simulated light deprivation in conditions of round-the-clock darkness (24-hour darkness) for 21 days; group 3 (n=6) – animals with simulated dark deprivation under conditions of round-the-clock lighting (24 hours light) for 21 days. For morphometric assessment, 30 non-overlapping fields of view were analyzed in each preparation at a magnification of 100,000. The number of mitochondria and lysosomes was calculated per 100 μm2 area of the cytoplasm of cells of a certain morphological type. Using the ImageScopeM application program, the average cross-sectional area of mitochondria (μm2) and the average relative electron density of their matrix were determined. During chronodestruction, significant ultrastructural changes are observed in sebocytes, which indicate a change in the functional activity of the cells. During dark deprivation, the functional activity of sebocytes increases, and this, in turn, leads to a significant change in their secretory activity. At the same time, light deprivation leads to an increase in proliferative activity in the sebaceous gland with a simultaneous change in the chemical composition of sebum (polymorphism of granules).