with a highly sensitive chemiluminescence method

ABSTRACT: A highly sensitive chemiluminescence (CL) method for evaluation of medical radiation damage degree is presented. According to the principle of cell stress response to ionizing radiation, lymphocytes will produce reactive oxygen species (ROS) after irradiation. The ROS produced can react with 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-α] pyrazin-3-one (MCLA), a specific CL probe for superoxide anion (O2· −) and singlet oxygen (1O2), to emit light at 465 nm. The CL intensity is posi-tively related to the amount of generated ROS detected 30 min after irradiation. Cell viability, which is inversely related to cell mortality, was determined by MTT assay after 3 days ’ culture. The results show that both CL intensity and cell mortality of lymphocytes increase with the increase of the radiation dose when the dosage is no more than 3 Gy, suggesting a positive relation-ship between the degree of lymphocyte cell damage and the amount of ROS generated. In addition, the effects of catalase, Cu–Zn superoxide dismutase (SOD), mannitol, sodium azide (NaN3), and D2O on MCLA-dependent CL of lymphocytes are discussed. We believe that the MCLA-dependent CL method would potentially provide an easy way for evaluating the degree of lymphocyte damage induced by radiation. Copyright © 2004 John Wiley & Sons, Ltd