THE RESPONSE OF IMMUNE CELLS - CD68+ - MACROPHAGES DURING PHYSICAL EXERCISE

Liver macrophages are a heterogeneous population of immune cells that form the mononuclear phagocyte system, capable of responding to tissue damage and participating in the regulation of the inflammatory response and liver cell regeneration. Macrophages interact with hepatocytes, stellate cells, and sinusoidal endothelial cells to maintain homeostasis.

Objective: To study CD68+ macrophages in the liver during water loading of varying intensity.

Materials and Methods: Male Wistar rats (n=30) were used in the experiment, which were subjected to water loading of varying intensity. After the animals were withdrawn from the experiment, liver samples were collected for histological and immunohistochemical examination.

Results: Microscopic examination of the liver during mild physical exertion revealed vascular congestion and degenerative changes. The number of CD68+ cells was 10.34±2.48 (in the liver of the intact group, CD68+ cells were 7.28±2.41). Necrobiotic changes were detected with moderate physical activity. The number of CD68+ cells slightly increased compared to the intact group. With severe physical activity, histological examination revealed destructive changes. The proportion of CD68+ - positive cells increased. According to the morphological description, several types were identified. There was an increase in the percentage of small macrophages (area 0-115.78) due to a decrease in the proportion of medium (area 115.78-240.7), with an unchanged proportion of large (area 240.7-368.1) CD68+ macrophages. By the 30th day of the experiment, the studied parameters during physical activity of light and moderate intensity approached the figures in the intact group. During intense physical exertion, the percentage of CD68+ positive cells decreased but remained higher than in intact animals, likely due to the development of a reparative process in the liver tissue.

Conclusion: Changes in the morphology and proportion of CD68+ macrophages of varying sizes were observed, with an increase in the percentage of small CD68+ macrophages and CD68+ expression on their surface.