Immune parameters in the blood of rats under conditions of chronic unpredictable mild stress of different durations

Abstract

Long-term stress causes dysregulation of most components of the immune system. The great interest of researchers in studying the complement system and cytokines is associated with a wide range of their functions. The purpose of the study was to study the concentrations of cytokines and the functional activity of the complement system in the blood of rats using a model of chronic unpredictable mild stress of different durations.

Methods. The study was conducted on 42 male Wistar rats. There were 5 experimental groups: control group; four experimental groups that were subjected to repeated stress loads in a chronic unpredictable mild stress model for 1, 2, 3 and 4 weeks, respectively. The concentration of IL-4 and IL-10 in the blood serum of rats was determined by solid-phase enzyme immunoassay, the functional activity of the complement system was determined using a screening test in the reaction of complement-dependent lysis of human erythrocytes.

Results. A statistically significant increase in the level of IL-10 was revealed after 2, 3 and 4 weeks, but a decrease in the concentration of IL-4 in the blood of rats after 2 and 4 weeks of stress exposure. The functional activity of the complement system increased after 2 weeks of chronic stress, but did not differ from control values in subsequent periods.

Conclusion. The identified changes illustrate the specificity of the activity of the cellular and humoral components of the immune response under conditions of repeated unpredictable stressors of varying duration.