[The role of cell hypoxia in the effect of radiation protectors]

In experiment with mice, rats and dogs the intimate relationship has been established between radioprotective efficiency of indraline, cystamine and mexamine and its properties to enhance succinate dehydrogenase (SDG) activity of blood lymphocytes (r = 0.95). In that analysis modifying effect of normobaric hyperoxia has been estimated. Mice and dogs were correspondingly irradiated with gamma-60Co-rays in the dose 8.33 and 3.16 Gy. In the investigation involving mice, dogs and men the effect-dose dependence of aggravating of the SDG activity was linear for indraline, but not for cystamine. In man hypoxic hypoxia with air-hypoxic mixture containing 10% of oxygen has initiated rise of the SDG activity being twice as smaller as the one when indraline in the dose of 100 mg administrated. Hyperoxia suppressed radioprotective properties of indraline, cystamine and mexamine in the ED50 in term of DRF by twice and didn't virtually influenced on that in the optimum radioprotective doses. Hyperoxia and alpha-adrenoblocator tropaphene also suppressed the SDG response to indraline. In vitro experiment cystamine and adrenaline held stimulating action on SDG of blood lymphocytes. The role of pharmacological stimulation of cell respiration and cell hypoxia relating with the one in mechanism of radioprotective effect of the radioprotector of two dissimilar groups was discussed.