Effects of age and gender on the baseline and 2 Gy Co γ-ray-induced nucleoplasmic bridges frequencies in the peripheral blood lymphocytes of Chinese population.

Baseline nucleoplasmic bridges (NPB) vary widely in the general population from different regions in the same country or from different countries. The baseline NPB level in the normal Chinese population and the factors affecting the baseline and radiation-induced NPB levels have not been explored yet. The cytokinesis-block micronucleus cytome assay was conducted on the peripheral blood samples of 121 healthy individuals for the baseline NPB and 52 healthy individuals for the 2 Gy γ-ray-induced NPB level. The effects of age and gender on the baseline NPB and 2 Gy γ-ray-induced NPB level were evaluated. The overall baseline NPB in the peripheral blood lymphocytes of 121 healthy adults from the general population in China was 0.46 ± 0.20 per 1000 binucleated (BN) cells. The overall baseline NPB in males (0.56 ± 0.15 per 1000 BN cells) was higher than that in females (0.36 ± 0.22 per 1000 BN cells, P < 0.05). The effect of age on the baseline NPB was not significant, except for females in the 40-year age group. The overall 2 Gy γ-ray-induced NPB frequency for male donors was lower than that for female donors (P < 0.01). No evident trend of the radiation-induced NPB level with increasing age was observed for both genders. For the baseline micronucleus (MN) and radiation-induced MN levels, the effects of gender and age were confirmed. Therefore, the gender of donors affects the baseline and radiation-induced levels of NPB and MN. In addition, the effect of the age of the donors on the baseline and radiation-induced NPB levels showed no clear pattern and needed to be further investigated.