补充脱氧嘌呤和嘧啶核苷对淋巴细胞DNA损伤修复的影响

目的　脱氧核苷是构成 DNA分子的重要组分 ,通过补充脱氧嘌呤和嘧啶核苷探讨对 DNA损伤修复的影响。方法　采用“彗星”电泳技术分析 DNA断裂损伤 ,用 1 0 0 μmol/LH2 O2 诱导人体外周血淋巴细胞 DNA损伤后分为两组 :一组为对照组 ,另一组为脱氧核苷补充组( 2 0 μl,1 0 -4 mol/L)。结果　对照组淋巴细胞从初始到培养 2 h后 DNA损伤程度逐渐下降 ,由1 67.75下降为 68.1 ( AU) ;而补充脱氧胸苷组 DNA损伤修复能力与对照组相比无明显增高 ,同时补充 DNA合成所必须的四种脱氧核苷经过 3h的培养后也没有出现明显促进 DNA损伤修复的作用。结论　体外补充脱氧核苷对 DNA修复未显示有意义的作用 ,与 DNA损伤修复过程利用脱氧核苷的途径可能不同于 DNA的复制合成有关

EFFECT OF NUCLEOSIDES SUPLEMENTATION ON THE REPAIR OF DNA OXIDATIVE DAMAGE IN LYMPHOCYTES

Objective: It was to study the effect of supplementation of deoxythymidine, deoxyadenosine, deoxycytidine and deoxyguanosine on the repair of DNA oxidative damage. Methods: The human lymphocytes were divided into two groups, one was treated with nucleosides (20μl, 10 -4 mol/L) and another as control DNA damage was induced by H 2O 2 treatment and measured by comet assay (SCGE). Results: DNA oxidative damage in control group was gradually decreased from 167.75 down to 68.1 arbitrary units in 2 hours culture, whereas the repair of DNA damage in the supplemented group of deoxythymidine was not improved. Moreover, there was no significant increase in the rate of DNA repair in the supplemented groups as compared with the control group. Conclusion: The nutritional status of nucleosides may not play a key role in the base excision and nucleotide excision repairs of DNA oxidative damage. WT5”FZ]