Genetic effects of low dose radiation: DNA damage and micronucleus in X-rays treated cells

PONZINIBBIO M.V.; CRUDELI C.; PERAL GARCIA P.; SEOANE A.

ACTA RADIOLOGICA

TAYLOR & FRANCIS LTD

Año: 2010 vol. 51 p. 1028 - 1033

0284-1851

Owing to its ability to deposit energy within the cells, ionizing radiation has some unique characteristics as a mutagenic and carcinogenic agent and there is no doubt about the risk that the exposure to high doses of ionizing radiation poses for human health (1, 2). However, exposure to environmental, diagnostic, and occupational sources of radiation frequently involves low doses. Although these doses have no immediately noticeable impact on human health, there is great interest in their long-term biological effects (3). Clearly, it is important for the sake of the general population to investigate the effects of low-dose exposure in a range close to that found in occupationally exposed individuals. Evidence from several studies conducted among radiation-exposed individuals or cells showed signifi cant increases in the frequency of chromosomal aberrations or micronuclei (4 – 12). In addition, radiation-induced DNA damage in individual cells was usually evaluated by the single cell electrophoresis or comet assay, which is commonly used as it is considered to be simpler and faster than other assays (10, 13 – 16). Comparative investigations between the comet assay and the micronucleus test using radiation or chemicals as mutagens have been carried out (17 – 21). In this sense, MALUF et al. (22) reported that the micronucleus frequency was signifi cantly correlated with the comet assay damage index; and HE et al. (23) found that the DNA damage induced by 0.05 Grays (Gy) (50 mGy) of ionizing radiation could be detected by means of the comet assay but the micronucleus rate did not increase signifi cantly until a radiation dose of 0.25 Gy was delivered.