Direct assay of radiation-induced DNA base lesions to mammalian cells. Final progress report, September 1, 1991--November 1, 1993

摘要

We have successfully developed the GC/MS technique so that an assessment of base damage in mammalian cells can be accomplished. The technique now has a sensitivity that will allow one to perform research in the low dose region suitable for hazards evaluation. The research on the hydrated DNA molecule has been seminal in generating a better understanding of the mechanisms by which low LET radiation induces DNA damage in mammalian cells. Also reported here are (1) the methodology for hydrating and irradiating DNA has been developed, (2) the procedures for identifying and quantitating radiation-induced DNA damage by HPLC and GC/MS have been mastered, (3) an hypotheses that radiation-induced damage in closely associated water molecules can result in DNA damage which is indistinguishable from that caused by direct ionization of the DNA has been generated and supported by experimental data, and (4) mathematical expressions that relate DNA lesion formation to the important parameters in the above hypotheses have been constructed so that the predictions of the hypotheses can now be tested.