Dose-effect of nucleoplasmic bridges frequencies in human peripheral blood lymphocytes induced by60Coy-rays

Objective To establish the analysis criteria of nucleoplasmic bridges （NPB） and a dose-response curve of NPB frequencies in human peripheral blood lymphocytes irradiated by 60Coy-rays. Methods Human peripheral blood samples were collected from three healthy males, and were irradiated with O, 1, 2, 3, 4, 5 and 6 Gy of 60 Co y-rays. A cytokinesis-block micronucleus assay was carried out to analyze NPBs and micronuclei （MN） in binucleated cells. Results NPBs in binucleated ceils at each dose level of ,/-ray was conformed to the Poisson distribution. The dose-response curve of the y-ray-induced NPB frequencies in human peripheral lymphocytes followed the linear-quadratic model y = （ 1.39 × 10 -3 ）x2 ＋ （4.94× 10-3）x （R2 =0.981, P 〈 0.05）. Conclusions The dose-response curve of NPB frequencies in human peripheral blood lymphocytes induced by 0 -6 Gy 60Co y-rays was established. Key words: Ionizing radiation;  Nucleoplasmic bridge;  Micronucleus;  Dose response