Fig. 5

The anti-apoptosis effect of different concentrations (0, 0.25, 1, 4 mmol⋅L⁻¹) of AA-Tempol pretreatment for 1 h was analyzed using Annexin V/propidium iodide staining in a flow cytometry assay. a AA-Tempol pretreatment attenuated radiation-induced apoptosis in HUVEC cells. b The bar graph of apoptotic cells expressed as a percentage of total cells for each treatment with SAA from six experiments. Data are presented as mean ± S.D. (n = 6). ** P < 0.01 vs. 8 Gy group. Q1, Q2, Q3 and Q4 represent dead, late apoptosis, vital and early apoptosis cells, respectively