Lymphocytes are the most radiosensitive cells. After exposure to IR die by apoptosis at a rate proportional to the dose received.
We demonstrated that one hour after whole-body irradiation of rats, histone H2AX in the lymphocyte nuclei was quickly phosphorylated on serine 139. In the work presented here, we studied the kinetics of lymphocyte depletion in the blood and phosphorylation of histone H2AX in the peripheral blood lymphocytes after local (thoracic) irradiation of rats.
Twenty-four hours after whole-body irradiation of the rats at a dose of 5 Gy, the lymphocyte count declined to almost zero values, whereas after local irradiation of the thorax area, the counts of lymphocytes in the peripheral blood remained unaltered. We employed flow-cytometric and microscopic gamma H2AX determination 1 h after thoracic irradiation of rats.
We revealed a dose dependence on the increase in gamma H2AX in a dose range of 10-30 Gy. The microscopic method was more sensitive in the case of lower radiation doses.