Keywords: gamma-irradiation, mice, cytogenetic damage, bone marrow cells, low dose rates, spontaneous mutagenesis, adaptive response, low radiation, animal ageing
Investigation of the low-dose γ-irradiation effect on the spontaneous and high-dose radiation-induced level of cytogenetic damage in mouse bone marrow cells in vivo
The effect of low-dose gamma-irradiation (0.1 or 0.2 Gy with a dose rate of 0.125 Gy/min) of mice on the spontaneous and high-dose radiation-induced level of cytogenetic damage during ageing of animals was studied using the micronucleus test. It was shown that a single low dose of gamma-radiation induces a cytogenetic adaptive response in mouse bone marrow cells, which persists for up to 12 months after irradiation; the ability of inducing the adaptive response does not depend on the age of animals at the moment of adapting irradiation; single low-dose γ-irradiation decreases the cytogenetic damage to a level below the spontaneous rate at the end of the lifetime (20 months) of animals. The mechanisms underlying adaptive response not only protect from cytogenetic damage induced by high-dose irradiation but also may play a role during spontaneous mutagenesis.