Radiation-induced adaptive response of nucleoplasmic bridges in human peripheral blood lymphocytes / 中华放射医学与防护杂志

ABSTRACT

Objective To explore whether a low dose of 60Co γ-rays could induce the adaptive response in the formation of nucleoplasmic bridges (NPB) in human peripheral blood lymphocytes,and if so,the range of the priming dose.Methods Human peripheral blood samples from healthy males were collected and irradiated with 0,20,50,75,100,150 and 200 mGy (dose-rate was 25 mGy/min) of 60Co γ-rays.After 6 h,the samples were irradiated with a challenge dose of 2 Gy (dose-rate was 1 Gy/min).The cytokinesis-block micronucleus (CBMN) assay was carried out to analyze the NPB and micronuclei (MN) formation in binucleated cells.Results Within the dose range of 0-200 mGy,the yields of NPB and MN increased with irradiation dose of γ-rays and the dose response of NPB followed with a linearquadratic equation of y =(1.5 × 10-4) x2-(5.67 × 10-3)x + 0.598 (R2 =0.893 8).Compared with the samples irradiated with 2 Gy alone,the yields of NPB and MN were significantly reduced when the samples were irradiated with a priming dose of 75-100 mGy before 2 Gy irradiation (U =2.66,2.97,3.96,5.89,P ＜0.05).The biggest decrease ratio of NPB yields approached to 43.2％ at the priming dose of 100 mGy.Conclusions Low doses in the range of 75-100 mGy of 60Co γ-rays could induce the adaptive response of NPB formation in human peripheral blood lymphocytes.