mBAND analysis of chromosome aberrations in lymphocytes exposed in vitro to alpha-particles and gamma-rays.
OBJECTIVE
To investigate the profiles of chromosome damage induced in vitro by exposure to alpha-particles and gamma-rays.


METHODS
Human peripheral blood lymphocytes were exposed to three dose regimes: alpha-particle doses of 0.2 and 0.5 Gy and a gamma-ray dose of 1.5 Gy. After culturing for 47 hours, chromosome aberrations involving the number 5 chromosomes were identified using a multi-coloured banding (mBAND) technique.


RESULTS
Analysis of the frequencies of chromosome 5 breaks within aberrant cells and within aberrant number 5 chromosomes demonstrated that alpha-particle irradiation is more likely to result in multiple breaks in a chromosome than gamma-irradiation. Additionally, overdispersion was observed for all doses for the distribution of breaks amongst all cells analysed and breaks amongst total number 5 chromosomes, with this being greatest for the 0.2 Gy alpha-particle dose. The ratio of interchanges to intrachanges (F ratio) was 1.4 and 2.4 for 0.2 and 0.5 Gy alpha-particles respectively and 5.5 for 1.5 Gy gamma-rays. Evaluation of simple versus complex exchanges indicated ratios of 1.9 and 2.7 for 0.2 and 0.5 Gy alpha-particles respectively and 10.6 for 1.5 Gy gamma-rays. The majority of the intrachanges involving chromosomes 5 induced by alpha-particle radiation were associated with more complex exchanges.


CONCLUSIONS
This study has confirmed that exchanges induced by exposure to high linear energy transfer (LET) alpha-particle radiation comprise a greater proportion of intrachanges than those induced by exposure to low LET gamma-rays. However, since the majority of these are associated with complex rearrangements and likely to be non-transmissible, this limits their applicability as a marker of past in vivo exposure.
Tawn
E Janet
EJ
Westlakes Research Institute, Moor Row, Cumbria, UK. ejtawn@uclan.ac.uk
Janet
E
E
Whitehouse
Caroline A
CA
Holdsworth
Duncan
D
De Ruyck
Kim
K
Vandenbulcke
Katia
K
Thierens
Hubert
H
D000512:Alpha Particles / Q000009:adverse effects*; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D019457:Chromosome Breakage / Q000528:radiation effects; D002877:Chromosomes, Human / Q000528:radiation effects* / Q000648:ultrastructure; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects* / Q000648:ultrastructure