COMPARISON OF THE EFFECTS OF LOW DOSES OF

PONZINIBBIO MV,; CRUDELI C,; MIRA A,; SEOANE A.

BIOCELL

Lugar: Mendoza; Año: 2008 p. 134 - 134

0327-9545

Studies carried out during the last decade have shown that the risk of low doses of ionizing radiation exposure is higher than the one expected from high doses extrapolation. Ionizing radiation induces a great deal of alterations in the genetic material, causing break in one or both DNA strands. The aim of the present research was to compare the effect produced by very low doses of X-ray (10, 20, 30, 40, 50 mGy) in different cell lines: one transformed (CHO-K1) and one normal and diploid ( MRC-5). For this purpose the alkaline version of the comet assay was employed immediately after exposure. One hundred cells were analyzed for each treatment and classified according to the level of damage. The obtained data showed a dose-dependent increase in the DNA damage in both cell lines. Nevertheless, the index of damage in CHO-K1 cells was lower than in MRC-5 cells in all treatments. These results support the idea that the transformed cells would be more resistant to this genotoxic agent than those coming from primary cultures. Despite the evaluation was performed with cells from different species (human and hamster) it may be possible to suggest that the response to low doses of radiation would depend on the genetic structure of the target cells.