Involvement of Recovery Processes in the Effects of Radioprotectors at the Cellular and Organismal Levels

A correlation between the effectiveness of the radioprotective action of cysteamine with the radiosensitivity of cells and their ability to recover from radiation damage was demonstrated for diploid yeast cells of S. cerevisiae. To demonstrate the involvement of the recovery processes in the mechanism for radioprotective action of the T1023 compound in animals, data on the survival of clonogenic bone marrow cells of mice exposed to ionizing radiation are presented. It is shown that the radioprotective effect of this compound can be realized not only at the physicochemical stage of formation of radiation damage due to a decrease in the oxygen content in tissues but also due to the post-radiation cell recovery at the biochemical stage. This is confirmed by the presence of the sigmoid part of the dose-response curve in the region of low doses of ionizing radiation.