The level of DNA damage in mouse hematopoietic cells and in frog and human blood cells, as induced by the action of reactive oxygen species in vitro.

Comparative studies of the level of DNA damage induced in vitro by X-rays (0-8 Gy) or hydrogen peroxide (0-300 µM) in cells of blood, spleen, and bone marrow of mice and in blood cells of frogs and humans were performed using the alkaline comet assay. For both agents, the levels of induced DNA damage in leucocytes/splenocytes of mice were higher than those in blood cells of frogs and humans, while in human leucocytes, they were comparable with those in frog blood cells. The rate of DNA repair in frog blood cells was very slow. The results suggest that the levels of radiation-induced DNA damage are not in accordance with species radiosensitivity (according to LD50/30) but rather with the intrinsic peculiarities of cells.