Rats were irradiated by 1-10 Gy of gamma radiation. Value LD50/60 was 7.37 (4.68-8.05) Gy.
Histone H2AX is phosphorylated by ATM kinase on serine 139 (gamma H2AX) quickly after the irradiation. It forms microscopically visible foci in the site of double strand breaks of DNA.
Flow-cytometric method was used for quantitative detection. This study evaluated dose-dependency of H2AX phosphorylation in peripheral lymphocytes of rats irradiated by whole-body dose 1-10 Gy.
Our data show a dose-dependent increase in gamma H2AX in rat peripheral blood lymphocytes 1 h after whole-body irradiation by the dose of 1-10 Gy. We proved that phosphorylation of histone H2AX is a prompt and reliable indicator of the received radiation dose suitable for rapid measurement before the number of lymphocytes in blood starts to decrease.
It can be used already 1 h after the irradiation for an estimation of the received dose of radiation. Blood can be stored in 4 degrees C for 23 h without significantly affecting the result.