Protection of mice against X-ray injuries by the post-irradiation administration of inosine-5'-monophosphate.

The aim of the present study was to investigate the radiation modulating properties of inosine-5'-monophosphate (IMP). Mice injected introperitoneally (i.p.) with IMP 15 minutes after irradiation with a lethal irradiation dose of 7 Gy have better survival rates comparative to irradiated mice non treated with IMP. The dose reduction factor of the IMP is 1.22. Using a hematologdical test we demonstrated that administration of IMP alleviates the symptoms of radiation-induced leukopenia and thrombocytopenia. The DNA damage in bone marrow and thymus cells of irradiated mice was measured by flow cytofluorometry and micronucleus test (MN-test). The tests show that i.p. administration of IMP to irradiated animals leads to a significant reduction of the DNA damage level. In this paper we show that IMP substantially modulates the damaging effects of ionizing radiation protecting irradiated mice and it is a promising agent for a treatment of leukopenia.