Department of Toxicology, School of Public Health, Soochow University, Suzhou, China.
J Toxicol Environ Health A. 2012;75(12):694-9. doi: 10.1080/15287394.2012.690086.
Oxidative damage can be induced by many environmental stressors. 8-Hydroxydeoxyguanosine (8-OHdG) has been used as a biomarker of oxidative DNA damage in both in vitro and in vivo studies. In the present study, Wistar rats were exposed to radon gas at a concentration of 100,000Bq/m(3) for 12 h/d for 30, 60, and 120 d, equivalent to cumulative doses of 60, 120, and 240 working level months (WLM), respectively. Changes in levels of 8-OHdG, reactive oxygen species (ROS), and total antioxidant (T-AOC), as well as expressions of some DNA repair enzymes such as 8-oxoguanine DNA glycosylase (OGG1) and MutT homolog 1 (oxidized purine nucleoside triphosphatase, MTH1), were determined in rat urine, peripheral blood lymphocytes, and lung after exposure to radon. The results revealed an increase in 8-OHdG and ROS levels, a decrease in T-AOC levels, and reduced OGG1 and MTH1 expression levels. The elevated amount of 8-OHdG in urine or lymphocytes was positively correlated with the cumulative exposure dose, whereas OGG1 and MHT1 expression levels in lung were inversely correlated with cumulative exposure dose. These findings indicate that oxidative damage induced by radon may be involved in radon-induced carcinogenesis.
氧化损伤可由多种环境应激源诱导产生。8-羟基脱氧鸟苷（8-OHdG）已被用作体外和体内研究中氧化 DNA 损伤的生物标志物。在本研究中，Wistar 大鼠每天暴露于浓度为 100,000Bq/m(3)的氡气中 12 小时，分别暴露 30、60 和 120 天，累积剂量分别相当于 60、120 和 240 个工作水平月（WLM）。在暴露于氡气后，测定大鼠尿液、外周血淋巴细胞和肺中 8-OHdG、活性氧（ROS）和总抗氧化剂（T-AOC）水平的变化，以及一些 DNA 修复酶如 8-氧鸟嘌呤 DNA 糖基化酶（OGG1）和MutT 同源物 1（氧化嘌呤核苷三磷酸酶，MTH1）的表达。结果显示，8-OHdG 和 ROS 水平升高，T-AOC 水平降低，OGG1 和 MTH1 表达水平降低。尿液或淋巴细胞中 8-OHdG 的增加量与累积暴露剂量呈正相关，而肺中 OGG1 和 MHT1 的表达水平与累积暴露剂量呈负相关。这些发现表明，氡诱导的氧化损伤可能参与了氡诱导的致癌作用。
