title: Ionizing-radiation-induced damage in the DNA of cultured human cells. Identification of 8,5-cyclo-2-deoxyguanosine.
abstract: Epstein-Barr-virus-transformed peripheral-blood B-lymphocytes were gamma-irradiated at 0 degree C at doses from 10 to 100 Gy. The cells were immediately lysed and the DNA was isolated. Subsequently, the DNA was hydrolysed to 2'-deoxyribonucleosides with a mixture of DNAase I, venom and spleen exonucleases and alkaline phosphatase. The hydrolysate was dried, trimethylsilylated and analysed by capillary gas chromatography-mass spectrometry with selected-ion monitoring. The (5'R)- and (5'S)-diastereomers of 8,5'-cyclo-2'-deoxyguanosine were observed in a ratio of 1:3, and their formation was dose-dependent. It was possible to detect and characterize one such lesion in approx. 4 X 10(4) guanine nucleotide subunits of DNA.
mesh_terms: D001402:B-Lymphocytes / Q000528:radiation effects; D002478:Cells, Cultured; D004247:DNA / Q000528:radiation effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis; D005720:Gamma Rays; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D013237:Stereoisomerism
chemical_list: C050888:8,5'-cyclo-2'-deoxyguanosine; D004247:DNA; D003849:Deoxyguanosine