Figure 1. (a) Response of HeLa cells to low-dose X-ray irradiation, measured 7 days post irradiation as capacity for resazurin reduction. Data are means and standard deviation (SD) for three independent experiments, except for control (zero dose) and 7.5 mGy where n=6. (b) Protection against the irradiation effect at 7.5 mGy by LNMMA (1 mM) but not by ascorbic acid (AA, 200 µM) or p38 MAPK inhibitor SB203580