Keywords: high-LET radiation, linear energy transfer, low dose radiation, micronucleus tests, high altitude flights, adaptive response, genetic instability, mice bone marrow, low radiation, dose dependence, irradiation
Adaptive response and genetic instability induced in mice in vivo by low dose-rate radiation simulating high-altitude flight conditions
The effect of a low dose-rate high Linear Energy Transfer (LET) radiation that simulates the spectral and component composition of radiation fields formed in the conditions of high-altitude flights on mice in vivo has been investigated. The dose dependence, Adaptive Response (AR) and Genetic Instability (GI) in the bone marrow of generation F1 of mice born from males irradiated under these conditions were examined using the micronucleus test. Irradiation was performed in the radiation field behind the concrete shield of the U-70 accelerator to accumulate doses of 11.5, 21.5 and 31.5 cGy (1 cGy/day). The experiments demonstrated that the irradiation of mice with these doses (1) increases the cytogenetic damage in polychromatic erythrocytes, (2) induces no AR and (3) leads to an increase in sensitivity to additional irradiation with a dose of 1.5 Gy of γ-radiation and the absence of AR in F1. These data indicate a GI in F1 born from irradiated males.