Effects of Combined Action of Low Doses Ionizing Radiationand Oxidative Stress Inducers on Hemostasis
The response of the body to any adverse effects is induced by the adaptation syndrome. The hemostasis system plays important role in the development of the syndrome. The paper presents results of the study of combined effects of low dose radiation, oxidative stress inducers - hyperoxia and antiorthostatic hanging (ANOH) – on the hemostatic system in Wistar rats. The animals underwent prolonged exposure to low dose γ-radiation: 4.8, 40 (radiation hormesis) and 200 mGy. The irradiation was carried out on <sup>137</sup>Cs panoramic irradiator. For anti-orthostatic hypokinesia the rats were suspended at the negative angle of 45° to the horizon in specially designed cages. The immobility lasted from 3 hours to 3 days. For single 3-hour hyperbaric oxygenation, the air pressure was increased to 1.15 atm. The control group consisted of clinically healthy animals kept under standard vivarium conditions. With a combination of gamma irradiation at a dose of 4.8 mGy, hyperoxia and ANOH, as well as irradiation at a dose of 200 mGy, hyperoxia and ANOH, there is no effective adaptation during the three-day period of aftereffect. In the hemostatic system, the formation of a hypercoagulable syndrome was observed, which indicates damage to the body. The combination of γ-irradiation at a dose of 40 mGy, hyperoxia and ANOH led to a normal level all the studied parameters of the hemostatic system by the third day after exposure to the above factors. Under the influence of such radiation hormesis, shifts in the hemostasis system reflect the response of the body’s regulatory systems aimed at maintaining homeostasis.