Mutation Induction in V79 Chinese Hamster Cells by Very Heavy Ions

Summary

Mutation induction (resistance to 6-thioguanine) in Chinese hamster fibroblasts (V79) by exposure to accelerated heavy ions (O, Ne, Ca, Ti, Ni, Xe, Pb and U with energies between 5 and 14·8 MeV/u) was investigated, covering a range of LET from 300 to about 15 700 KeV/μm. The LET-dependence of the mutation induction cross-section (σ_m) has, in a similar way to inactivation (σ_i), to be described by separate curves for each ion. Both σ_m and mutagenicity (σ_m/σ_i) decrease with increasing specific energy for any given ion. Relative biological effectiveness for mutation induction was found to be significantly smaller than unity for the ions and energies investigated.