Immune System Response after Immobilization Stress in the Background of Ionizing Radiation

Abstract

We studied the combined effect of gamma radiation (6 Gy, remote period) and immobilization stress on immunological reactivity. Materials and methods. To address this, we carried out experiments on 40 white male Wistar rats weighing 220 ± 20 g, which were divided into 4 groups: Group I - intact animals, group II - animals exposed to gamma radiation (dose of 6 Gy), group III - animals exposed to immobilization stress and group IV - animals exposed to combined exposure to gamma radiation (dose of 6 Gy) and immobilization stress. Animals in groups II and IV were irradiated 90 days before the study on the TERAGAM radiotherapeutic cobalt unit. In groups III and IV, animals were modeled for acute immobilization stress by immobilization for 6 h in bright light. Results. At the early period of immobilization stress, all indicators of the immune system, such as cellular, humoral and nonspecific phagocytic links of immunity were activated, indicating the activation of the general adaptive syndrome of the organism. The suppressive action of gamma radiation on the immune system was preserved in a remote period, with this suppression being revealed not only on the T-cellular link, but also on nonspecific phagocytic links, and the functional metabolic activity of neutrophils. In the remote period after the combined effect of sublethal gamma radiation and immobilization stress in the early stage of the adaptation syndrome, there was a decrease in all cells of the T system of immunity, in the functional ability of leukocytes, and in the mononuclear phagocytic system of the body. The experimental immobilization-radiation pathological process was accompanied by disorders of the functional activity of the essential adaptive systems of the body. Based on our results, we could conclude about the dominant role of ionizing radiation in immunological reactivity.
 HIGHLIGHTS
 
 At an early stage, after exposure to stress, the general adaptation syndrome is activated in the body
 The suppressive effect of gamma radiation on the immune status and phagocytic activity persists in the long term
 The pathological process that occurs under the combined effects of radiation and immobilization stress is accompanied by a violation of the functional activity of the most important adaptive systems of the body
 Under the combined influence of radiation and non-radiation factors, the radiation factor has a predominant influence
 
 GRAPHICAL ABSTRACT