Cytogenetic analysis in Chinese hamster cells chronically exposed to low doses of X-rays

GÜERCI, ALBA; DULOUT, FERNANDO; SEOANE ANALÍA

INTERNATIONAL JOURNAL OF RADIATION BIOLOGY

Taylor and Francis

Lugar: Canada; Año: 2003 vol. 79 p. 793 - 799

0955-3002

Purpose: It is important to develop simple experimental models toassess the induction of DNA damage and study the differentfactors involved under controlled conditions. This paper describesthe cytogenetic analysis carried out in Chinese hamster cells(CHO) sequentially exposed to very low doses of X-rays.Materials and methods: CHO cells were cultured for 14 passages.Irradiation treatment was performed once per passage, and threeirradiation doses were employed: 2.5, 5.0 and 10.0 mSv.Results: Sequential irradiation of CHO cells did not increase theyield of chomatid- or chromosome-type aberrations. However, asignificant increase of achromatic lesions (gaps) was found afterthe first or second X-ray dose, with all three irradiation dosesemployed.Conclusions: The variation in the frequency of gaps as well as thatin the mitotic index during the 14 cycles of radiation could be anindication of the induction of genomic instability. According tothis, continuous rises and falls in the frequency of gaps as well asin the mitotic index reflects the simultaneous induction ofendogenous DNA damage, cell death and cell survival.