title: Kinetics of UV-induced changes in deoxynucleoside triphosphate pools in Chinese hamster ovary cells and their effect on measurements of DNA synthesis.
abstract: Measurements of dNTP pools following exposure of Chinese hamster ovary cells to ultraviolet radiation reveals a rapid accumulation of cellular dTTP and a rapid loss of cellular dCTP. Exposure to 3-, 10- or 20 Jm-2 results in a 3-, 4- or 5.4-fold increase in cellular dTTP, respectively, within the first 10 min after exposure. dTTP levels then decrease noticeably, approaching the control value 3 to 5 hr later. In contrast, dCTP levels decrease rapidly within 10 min after exposure, ultimately to 1/10 that observed in the unirradiated control population. Recovery to normal dCTP levels is slow, taking in excess of 12 hr. No change in dATP is observed for 1-2 hr; subsequently, a moderate decrease in dATP levels occurs which is then followed by recovery, beginning 8 hr after irradiation. These results contrast with changes in dNTP pools observed in Chinese hamster V-79 cells exposed to mutagens. Measurements of rates of DNA synthesis by pulse-labeling cells with [3H]thymidine are also apparently affected by UV-induced transient deviations in the endogenous radiospecific activity of the labeled precursor.
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004261:DNA Replication / Q000528:radiation effects*; D003854:Deoxyribonucleotides / Q000378:metabolism* / Q000528:radiation effects; D005260:Female; D007700:Kinetics; D010053:Ovary; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014466:Ultraviolet Rays
chemical_list: D003854:Deoxyribonucleotides; D014316:Tritium; D013936:Thymidine