Oxidative and nitrative stress-related changes in human lens epithelial cells following exposure to X-rays.

HLE cell-line exhibited a bi-phasic response in terms of cell viability, ROS and RNS profiles. At doses <0.5 Gy, ROS and RNS levels were lower than control and at higher doses (>0.5 Gy) a steady increase was observed in each metabolite. This response was observed irrespective of dose-rate. Among the associations tested, cl, p, m-tyrosine and 3-nitrotyrosine revealed changes (p < .05) at 5 Gy compared exclusively to 0.05 and 0.01 Gy. In addition, dose-rate related differences were observed. Overall, the data suggests that ROS and RNS are key events in radiation induced damage and this response is dependent on the dose and dose-rate of IR exposure.