The kinetics of repair of oxidative DNA damage (strand breaks and oxidised pyrimidines) in human cells

摘要: Single cell gel electrophoresis is a sensitive method for detecting DNA strand breaks. Cells embedded in agarose are converted to nucleoids by treating with detergent and high salt. breaks render the nucleoid susceptible extension electrophoresis, forming ‘comets’. We find that when breakage resulting from H2O2 treatment examined, freshly isolated normal human lymphocytes relatively resistant compared transformed cells. When incubated after H2O2, HeLa cells repair most within 1 h, substantial fraction of oxidised pyrimidines (detected converting them endonuclease III) 4 h. However, less proficient at repair; during incubation h no detectable removal III-sensitive sites seen. While addition deoxyribonucleosides promotes completion UV damage lymphocytes, it has significant effect on oxidative damage.