高本底地区辐射对8-OHdG和hMTH1的影响研究

Impact of radiation on 8-OHd G and h MTH1 in high background radiation area

目的探讨天然低水平放射性辐射对氧化损伤及其修复基因表达水平的影响。方法选择广东省阳西县天然放射性高本底辐射地区（HBRA）和恩平市天然放射性低本底辐射地区（CA）各48名50-58岁土生土长男性居民为研究对象,按年龄匹配,佩戴热释光剂量计测得外照射剂量。采集外周血并分离血浆和白细胞,ELISA法测定血浆8-羟基脱氧鸟苷（8-OHd G）的含量,QPCR法测定血白细胞人8-羟基鸟嘌呤核苷酸酶修复基因（Human Mut Thomologue,h MTH1）m RNA转录水平。结果 HBRA组和CA组居民外周血血浆中8-OHd G浓度分别为（0.27±0.11）μg/m L和（0.32±0.10）μg/m L,差异有统计学意义（P〈0.05）,与个人剂量呈负相关（rs=-0.271,P=0.013）;h MTH1 m RNAΔCt值分别为（9.61±2.51）和（10.01±1.24）,差异无统计学意义（P〉0.05）,但与个人剂量呈负相关（rs=-0.219,P=0.028）。结论长期暴露于天然放射性低本底辐射地区可降低居民氧化损伤水平、提高DNA损伤修复能力。

Objective To explore the natural low level radiation effect on oxidative damage and its repair geneexpression. Methods A total of 48 residents ranged from 50 to 58 years old were selected in Yangjiang high backgroundradiation area（HBRA）and Enping control area（CA）respectively,and all the residents were native born and raised,andmatched according to the age. They were adorned the thermoluminescent dosimetry（TLD）. The peripheral blood of eachsubject was drawn,and the expression levels of 8-OHd G and m RNA of gene h MTH1 were determined with the methods ofELISA and real-time quantitative PCR detecting system（QPCR）,respectively. Results The concentrations of 8-OHd G inHBRA and CA were（0.27±0.11）μg/m L,（0.32±0.10）μg/m L respectively,the former was lower than the latter（P〈0.05）,andthere was a negative correlation between the individual average annual effective dose and 8-OHd G（rs=-0.271,P=0.013）; them RNA expression level of gene h MTH1 in HBRA and CA were（9.61±2.51）ug/m L,（10.01±1.24）μg/m L respectively,andthe difference was not significant（P〉0.05）,but there was a negative correlation between the individual average annualeffective dose and h MTH1（rs=- 0.219,P=0.028）. Conclusion Long- term exposure to high background radiation maydecline the level of oxidative damage and enhance DNA damage repair capacity.