The effect of low dose-rate radiation on thiol-disulfide system and lipid antioxidants in blood plasma of exposed persons

Understanding of mechanisms of non-specific resistance to damaging agents, such as low dose-rate ionizing radiation, is an area of our interest. Redox status of the glutathione system (GSH, GSSG) and lipid antioxidants, vitamins E and A, in the blood plasma of people exposed to low dose-rate radiation following the Chernobyl accident was examined in 4, 5, 6, 7 and 20 years after the exposure. Obtained data demonstrate complex interactions between watersoluble and lipid antioxidants in blood plasma of exposed people of different ages. The antioxiadant systems respond variously to low dose radiation (0.1-20 cSv) and high doses radiation (20-150 cSv), Exposure to low doses of low-dose-rate radiation may produce more pronounced effects on redox balance as compared with effects from exposure to high dose radiation of the same dose-rate. Different effects of low and high radiation doses on antioxidant systems can be due to sensibilization of these systems to radiation caused by damage of regulatory interactions in the processes, in which free radicals participate. The alteration of glutathione reduced and oxidized forms ratio due to significant increase in the GSH concentration (a biomarker of "harm") in blood plasma in people exposed to low dose radiation of low dose-rate can be critical, when glutathione antioxidant transforms into glutathione pro-oxidant.