The Influence of the Superoxide Dismutase Preparation Rexod® on Survival of CFU–S in С57ВL/6 Mice Exposed to Irradiation.

The radioprotective efficiency of the Rexod^® drug (State Research Institute of Highly Pure Biopreparations of the Federal Medical-Biological Agency of Russia) containing recombinant human superoxide dismutase (SOD) has been investigated in terms of survival and proliferative activity of hematopoietic stem cells in male С57Вl/6 inbred mice of the SPF category after acute external γ-irradiation. The animals were subjected to radiation from an IGUR-1M apparatus containing a source of ¹³⁷Cs, and the γ-exposure dose was within the range of 3.0–7.5 Gy, while the absorbed dose-rate was 0.78 Gy/min. A single dose of 180 mg/kg of recombinant SOD in a volume of 1 mL was administered intraperitoneally 15 minutes prior to irradiation. Mice from the control group similarly received the same volume but of normal saline. The radioprotective properties of SOD were assessed based on the amount of CFU–S in the endotest, nucleated cells (NCs) in the bone marrow and thymus, erythrocytes and leukocytes in the peripheral blood, and the weights of the thymus and spleen in the dynamics. It was shown that the use of SOD made it possible to increase the survival of CFU–S after acute sublethal γ-irradiation of mice at a dose of 4Gy. The registered changes in the amount of CFU–S and other hematological parameters might testify to the fact that the administered SOD stimulated hematopoiesis in the spleen. The revealed stimulatory effect of SOD on the erythropoiesis and the number of NCs in the thymus in both irradiated and nonirradiated animals opens up new opportunities for the use of the preparation and requires further studies of the mechanisms of the detected effects. [ABSTRACT FROM AUTHOR]