[The kinetics of the chemical modification of DNA radiation transformations in multicomponent systems. An analytical...

Most probable ways of chemical protection and sensitization of DNA macromolecules under the effect of ionizing radiation in aqueous solutions have been investigated. A kinetic model in proposed, based on the experimental data available, that consists of 25 reactions involving DNA (D), protein (P), glutathione (G), oxygen (O2), various protectors and sensitizers (A), active products of water radiolysis (O, e (H)), free and peroxide radicals of DNA and other components, and peroxides. General and partial rates of radiation transformations of DNA, depending on D, P, G, O2 and A concentrations are expressed in analytical terms. The relationships obtained are used for a qualitative description of some biological effects of ionizing radiation that is: a difference in radiosensitivity of different organs and tissues and its alteration during the cell cycle; oxygen effect; and the concentration relationships of the radioprotection and radiosensitization coefficients.