Comet Assay Study Of DNA Breakage And Apoptosis In Mice Exposed To Low Dose-Rate Ionizing Radiation

The DNA strand breaks level and apoptotic cells rate in spleen cells of CBA male mice continuously (40-365 days) exposed to very low dose-rate (0.17 cGy/day) y-radiation were investigated using the comet assay. It was shown that very low dose-rate irradiation resulted in statistically significant increase in the DNA strand breaks level, starting from a dose of 20 cGy. Further prolongation of exposure time and, hence, increase of a total dose did not, however, lead to further increase in the DNA strand breaks level. At the doses 20, 45, and 61 cGy approximately two-fold increase over a control level in the apoptotic cell fraction was observed