[Sensitivity to non-radiation effects in animals examined in the phase of increased radioresistance developed after sublethal irradiation].

The sensitivity to some non-radiation agents in mice which displayed an increased radioresistance 12 days following sublethal radiation was investigated. The animals demonstrated no enhanced cross-resistance to acute hypoxia, injections of KCN, strychnine, sarcolysine, hexenal. Resistance to typhoid fever endotoxin as well as the indices of nonspecific antimicrobial host defense (NBT-test, segregative activity of RES, white blood cell counts, antibody production ability) were reduced as compared with those of intact mice.

[Characteristics of mouse hematopoietic stem cells in the phase of enhanced radioresistance after sublethal irradiation].

Haemopoietic stem cells of mice which displayed an increased radioresistance 12 days following sublethal irradiation, exhibited higher proliferative, granulocyte-repopulating and migration activities as compared with those of intact animals.

[Number of hematopoietic stem cells in mice in the phase of increased radiation resistance following sublethal irradiation and change in their number after repeated exposure to radiation].

The content of haemopoietic stem cells in mice at the stage of the enhanced radioresistance (day 12 after irradiation with a sublethal dose of 2.75 Gy) was lower than that in the controls. Their repopulation in the repeatedly exposed mice was more intensive than in the intact mice irradiated with the same dose.