A critical comparison of the micronucleus yield from high and low LET irradiation of plateau-phase cell populations.
Experimental data are presented which cast doubt on the usefulness of micronucleus assays as a quantitative measure of radiation damage. Synchronised (G1) Syrian hamster fibroblasts (BHK21 C13) were exposed to doses of gamma- or neutron radiation which yielded equivalent survival response. The cultures were examined at intervals during a 120-h post-irradiation incubation, for the appearance of micronuclei. Dose-response curves for the micronucleus yield constructed at a single sample time of 30 h were compared with those for the peak yield, irrespective of sampling time at each dose. When the total production of acentric fragments was compared with the peak yield of micronuclei no clear correlation could be seen. Qualitative hypotheses have been suggested to account for the various features of the data. The production and expression of micronuclei has been found to be a very complicated relationship and is a warning against too simplistic an interpretation of micronuclei data.
D000818:Animals; D002453:Cell Cycle; D002460:Cell Line; D002467:Cell Nucleus / Q000528:radiation effects* / Q000648:ultrastructure; D002478:Cells, Cultured; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D004735:Energy Transfer; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D005720:Gamma Rays; D007399:Interphase; D007668:Kidney; D008647:Mesocricetus; D009152:Mutagenicity Tests; D009502:Neutrons