Influence of radiation quality on heavy ion induced chromosome aberrations in V79 cells

The induction of chromosome aberrations after irradiation of V79 Chinese hamster cells with Ar-ions at energies of 10.5 MeV/u (LET 1100 keV/μm) and 75 MeV/u (LET 250 keV/μm) was studied up to 24 hours after irradiation. For comparison also X-ray experiments were performed. Analysis of data was based on the same level of cell survival (20%). Our data indicate a correlation between the radiation quality determined by track parameters and the induction of chromosome aberrations. 75 MeV/u Ar-ions characterized by a lower ionization density are more effective in the induction of chromosome damage than 10.5 MeV/u Ar-ions. Also, the induction of a special aberration type, i.e. the formation of exchanges, is favoured by the lower ionisation density. Additionally the radiation quality influences the progression of cells through the cell cycle. Immediately after irradiation a mitotic delay can be observed. With increasing ionization density the mitotic delay is more pronounced. The response of cells to particle radiation differs quite largely from those observed after X-ray irradiation. (orig.)