Frequency of Micronuclei in Lymphocytes Following Gamma and Fast-neutron Irradiations / 대한치료방사선과학회지

ABSTRACT

The dose response of the number of micronuclei in cytokinesis-blocked (CB) lymphocytes after in vitro irradiation with -rays and neutrons in the 5 dose ranges was studied for a heterogeneous population of 4 donors. One thousand binucleated cells were systematically scored for micronuclei. Measurements performed after irradiation showed a dose-dependent increase in micronuclei(MN) frequency in each of the doctors studied. The dose-response curves were analyzed by a linear-quadratic model, frequencies per 1000 CB cells were (0.31+/-0.049) D+(0.0022+/-0.0002) D2+(13.19+/-1.854) (r2=1.000, X2=0.7074, p=0.95) following irradiation, and (0.99+/-0.528) D+(0.0093+/-0.0047) D2+(13.31+/-7.309) (r2=0.996, X2=7.6834, p=0.11) following neutrons irradiation (D is irradiation dose in cGy). The relative biological effectiveness (RBE) of neutrons compared with -rays was estimated by best fitting linear-quadratic model. In the micronuclei frequency between 0.05 and 0.8 per cell, the RBE of neutrons was 2.37+/-0.17. Since the MN assay is simple and rapid, it may be a good tool for evaluating the y-ray and neutron response.