柴油废气成分分析及对DNA生物氧化能力

目的　通过研究以柴油为燃料的机动车尾气成分 ,及其对DNA分子的生物氧化能力 ,在分子生物学水平上探讨燃柴油机动车尾气污染物的遗传毒性效应与机制。方法　以DNA加合物 8-羟基脱氧乌苷 (8-OHdG)作为DNA氧化损伤的生物学标志物 ,用高压液相色谱 -电化学 (HPLC -EC)法对染毒后的DNA中 8-OHdG进行定量检测 ,通过气质联用法 (GC -MS)进行有机成分分析和原子吸收法 (AAS)对其进行无机元素分析 ,并从化学组成成分的角度探讨DNA分子生物氧化的分子机理。结果　在颗粒物和挥发性有机物中分别检出有机污染物 10 8种和 9种 ,无机元素 8种和 6种。尾气颗粒物和挥发性有机物均可在体外直接诱导DNA的氧化损伤 ,并呈现一定的剂量 -效应关系。结论　污染物直接的生物氧化作用 ,主要是污染物中存在多种痕量金属离子 ,如Fe2 、Cu2 等 ,在有氧环境中Fe2 可以逐渐被氧化为Fe3 ,同时O2 变为O· -2 。在Fe2 和Fe3 存在下 ,超氧阴离子O· -2 通过Fenton反应变为羟自由基·OH ,所产生的羟自由基可直接进攻DNA形成 8-OHdG ,或者进攻污染物中酚类化合物形成多酚或酮类化合物 ,这些化合物具有自氧化作用 ,进而生成大量的超氧自由基和羟自由基 ,构成循环反应。     

烹调油烟雾诱导核酸氧化损伤及其标志物8-羟基脱氧鸟苷的形成机制

目的 了解烹调油烟雾的遗传毒性效应。方法 以核酸加合物8-羟基脱氧鸟苷(8-OHdG)作为DNA氧化损伤的生物学标志物,用高效液相色谱-电化学检测法(HPLC-EC)对烹调油烟雾染毒的小牛胸腺DNA及Wistar大鼠气管灌注染毒的肺组织DNA中8-OHdG进行定量检测,通过气质联用法(GC-MS)进行有机成分和原子吸收法(AAS)进行无机元素分析,并从混合污染物化学组成成分的角度推断了烹调油烟雾造成DNA氧化损伤的分子机理。结果体外试验表明烹调油烟雾的各组分,包括油烟冷凝物、残留油、油烟颗粒物、油烟挥发性有机物均能能诱导DNA氧化产生8-OHdG,产生量的顺序为残留油>冷凝物>油烟颗粒物>油烟挥发性有机物。体内实验结果表明油烟冷凝物可诱导大鼠肺组织DNA的氧化且具有剂量一反应关系和时间一效应关系。结论烹调油烟雾具有明确的遗传毒性,可诱导核酸氧化产生加合物8-OHdG,其机制可能是烹调油混合污染物中存在痕量金属离子如Fe2+、Cu2+等,介导Fenton反应生成羟自由基,直接进攻DNA造成氧化损伤。     

香烟侧流烟雾引起的DNA分子氧化损伤

目的：通过研究环境烟草烟雾的侧流烟雾（ETSS）对DNA分子的氧化损伤，探讨环境烟草烟雾（ETS）的遗传毒性效应及其分子机制。方法：以DNA加合物8－羟基脱氧鸟苷（8－OHdG)作为DNA氧化损伤的生物学标志物，用高压液相色谱－电化学检测（HPLC－EC）法对ETSS染毒后的DNA中8－OHdG进行定量检测，通过气质联用法（GC－MS）对香烟烟雾进行有机成分分析和原子吸收法（AAS）对其进行无机元素分析，并从化学组成成分的角度探讨DNA氧化损伤的分子机理。结果：ETSS的颗粒物和挥发性有机物污染物123种和84种，有机元素7种，其中醌类，多酚等化合物具有自氧化作用，不需要任何生物活性系统，在体外就可产生大量的活性氧自由基，并在金属的催化作用下进攻DNA的碱基，形成加合物8－OHdC ,结论：ETSS对DNA具有氧化能力，体现了直接的遗传毒性效应，8－OHdG是DNA氧化损伤较好的效应标志物。     

香烟烟雾成分分析及其对DNA生物氧化能力研究

目的 从分子生物学水平上探讨香烟烟雾对DNA的生物氧化能力。方法 以DNA加合物8－羟基脱氧鸟苷（8－OHdG）作为DNA氧化损伤的生物学标志物,用高压液相色谱－电化学检测法对香烟烟雾染毒后的DNA中8－OHdG进行定量。通过气质联用法（GC－MS）对香烟烟雾进行有机分成分析,用原子吸收法（AAS）对其进行无机元素分析。结果 香烟烟雾颗粒物和挥发性有机物可不同程度地引起DNA基损伤产生8－OHdG,并分别检出有机污染物157种和78种,无机元素5种。香烟烟雾对DNA的生物氧化能力主要是由于存在大量有机污染物,其中的醌类、多酚等化合物具有自氧化作用,在体外可产生大量的活性氧自由基,并在金属的催化作用下进攻DNA的碱基,形成加合物8－OHdG。结论 香烟烟雾对DNA具有氧化能力,香烟烟雾具有直接的遗传毒性效应。     

丙烯醛对DNA分子的损伤作用

目的 通过研究丙烯醛对DNA分子的损伤,探讨丙烯醛的遗传毒性效应及其分子机制。方法 应用单细胞凝胶电泳技术检测丙烯醛引起的DNA断裂、DNA交联以及DNA．蛋白质交联;应用液相色谱．电化学法研究丙烯醛致DNA分子产生氧化损伤标志物8-羟基脱氧鸟苷(8-OHdG)。结果 丙烯醛可诱导人外周血淋巴细胞DNA发生链断裂,但不引起DNA-DNA、DNA-蛋白质交联;丙烯醛与小牛胸腺DNA的体外作用较弱,但在铁离子介导下对DNA的氧化能力增强。可产生一定量的8-OHdG加合物;动物实验表明丙烯醛诱导大鼠肺组织DNA氧化损伤生成少量8-OHdG。结论 丙烯醛具有直接的遗传毒性效应,产生自由基造成DNA氧化损伤是其遗传毒性效应的主要途径。     

室内生源性多环芳烃对DNA的氧化损伤

目的 了解室内生活污染来源-吸烟和烹调产生的多环芳烃(PAHs)种类与含量，及其对DNA的氧化损伤作用。方法 采集室内烹调油烟和环境烟草烟雾颗粒物，应用气相色谱-质谱-选择性离子监测技术(GC-MS-SIM)定量检测10种PAHs，并用10种混合PAHs经气管灌注染毒大鼠，用液相色谱结合电化学检测技术测定肺组织DNA中产生的氧化损伤标志物8-羟基脱氧鸟苷(8-OHdG)。结果 PAHs广泛存在于烹调油烟冷凝物、油烟颗粒物以及环境烟草烟雾的主、侧流烟雾颗粒物之中。其标准混合物可诱导大鼠肺组织DNA氧化损伤形成8-OHdG，并呈现明确的剂量一反应关系。结论 PAHs的遗传毒性效应和潜在的致癌效应存在着一条氧化代谢产生羟基自由基进攻核酸的途径。     

高效液相色谱-电化学检测法测定尿中8-羟基脱氧鸟苷含量

活性氧引起的DNA氧化损伤与衰老和一些疾病有关。DNA中碱基鸟嘌呤C8位易受羟自由基攻击，形成碱基修饰产物8-羟基脱氧鸟嘌呤核苷(8-OHdG)。8-OHdG是DNA氧化损伤的特异产物，是公认的内源性及外源性因素对DNA氧化损伤的生物标志物。当机体修复机制正常时，8-OHdG可在酶的作用下从DNA链上切除并重新掺人正常的鸟嘌呤碱基，而切下的8-OHdG则经尿液排出体外。     

饮用水中非挥发性有机物的遗传毒性与脂质过氧化的关系

为探讨饮用水中非挥发性有机物的遗传毒性与脂质过氧化的关系。用ＳＯＤ显色试验检测了饮用水中非挥发性有机物的遗传毒性，并在体外借助微粒体模型测定其脂质过氧经水平。结果显示：ＳＯＳ反应与脂质过氧化作用高度相关，进而初步探讨了饮用水的遗传毒性机理。     

8-羟基脱氧鸟苷在污染物遗传毒性研究中的应用分析

遗传毒性是环境毒理学研究的一项重要内容。遗传毒性可以由多种环境因素,经过多种生物学机制引起。外源性氧化性环境污染物进入体内所致的生物大分子的氧化损伤,是遗传毒性最为常见的生物学机制之一。主要表现为生物大分子（如DNA、蛋白质、脂类等）氧化损伤,以及随之发生的结构和功能改变,并最终导致基因突变、细胞癌变及生成肿瘤等现象。8-羟基脱氧鸟苷（8-hydroxy-2-deoxyguanosine,8-OHdG）是活性氧自由基（如羟自由基、单线态氧等）攻击DNA分子中的鸟嘌呤第8位碳原子而产生的一种氧化性加合物,它是活性氧基团引起的DNA氧化损伤修饰产物之一。     

8-羟基脱氧鸟苷检测方法研究进展

8-羟基脱氧鸟苷(8-Hydroxy-2′-deoxyguan ine,8-OHdG)是活性氧自由基(ROS)引起DNA氧化损伤修饰产物之一,其生成原因很多,主要是电离辐射、化学致癌物代谢活化及细胞正常新陈代谢过程产生大量ROS直接攻击DNA中的鸟嘌呤(dG),使脱氧鸟苷氧化为8-OHdG。8-OHdG可被机体特异性DNA修复酶剪切清除并经肾脏随尿排泄,其含量反映机体氧化损伤程度,既是个体接触标志物,又是效应标志物[1]。它一旦逃避了机体自身修复,就可能成为致突变、致畸、致癌的启动因子[2]。8-OHdG在体内稳定存在,为代谢终产物,且只能通过DNA氧化损伤途径形成,并可通…     

Oxidative Damage of the Extracts of Condensate,Particulate and Semivolatile Organic Compounds from Gasoline Engine Exhausts on Testicles of Rats

Oxidative damage induced by extracts of condensate, particulate matters and semivolatile organic compounds from gasoline engine exhausts were investigated in testicles of adult Sprague-Dawley rats. The results showed that gasoline engine exhaust could increase the contents of malondialdehyde and carbonyl protein, decrease activities of superoxide dismutase and glutathione peroxidase, and induce DNA damage in testicle of rat. Taking together, the gasoline engine exhaust could promote oxidative damage of bio-macromolecular in testicles of rat and oxidative stress might be an alternative mechanism for male reproductive function of male mammals.     

Exposure to traffic exhausts and oxidative DNA damage

Aims: To assess the relations between exposure to traffic exhausts and indicators of oxidative DNA damage among highway toll station workers.

Methods: Cross-sectional study of 47 female highway toll station workers exposed to traffic exhausts and 27 female office workers as a reference group. Exposure assessment was based on average and cumulative traffic density and a biomarker of exposure, urinary 1-hydroxypyrene-glucuronide (1-OHPG). Urinary 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage. Plasma nitric oxide (NO) was measured as an indicator of oxidative stress related to traffic exhaust exposure.

Results: The mean concentration of urinary 8-OHdG was substantially higher among the exposed non-smokers (13.6 µg/g creatinine) compared with the reference non-smokers (7.3 µg/g creatinine; difference 6.3, 95% CI 3.0 to 9.6). The mean concentration of NO among the exposed (48.0 µmol/l) was also higher compared with the reference non-smokers (37.6 µmol/l; difference 10.4, 95% CI –0.4 to 21.2). In linear regression adjusting for confounding, a change in log(8-OHdG) was statistically significantly related to a unit change in log(1-OHPG) (ß = 0.372, 95% CI 0.081 to 0.663).

Conclusions: Results indicate that exposure to traffic exhausts increases oxidative DNA damage. Urinary 8-OHdG is a promising biomarker of traffic exhaust induced oxidative stress.

     

Urinary Arsenic Speciation and its Correlation with 8-OHdG in Chinese Residents Exposed to Arsenic Through Coal Burning

In contrast to arsenicosis caused by consumption of water contaminated by naturally occurring inorganic arsenic, human exposure to this metalloid through coal burning has been rarely reported. In this study, arsenic speciation and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels in urine were determined in the Chinese residents exposed to arsenic through coal burning in Guizhou, China, an epidemic area of chronic arsenic poisoning caused by coal burning. The urinary concentrations of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and total arsenic (tAs) of high-arsenic exposed subjects were significantly higher than those of low-arsenic exposed residents. A biomarker of oxidative DNA damage, urinary 8-OHdG level was significantly higher in high-arsenic exposed subjects than that of low exposed. Significant positive correlations were found between 8-OHdG levels and concentrations of iAs, MMA, DMA and tAs, respectively. In addition, a significant negative correlation was observed between 8-OHdG levels and the secondary methylation ratio (DMA/(MMA + DMA)). The results suggest that chronic arsenic exposure through burning coal rich in arsenic is associated with oxidative DNA damages, and that secondary methylation capacity is potentially related to the susceptibility of individuals to oxidative DNA damage induced by arsenic exposure through coal burning in domestic living.     

Organochlorines and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in cancerous and noncancerous breast tissue: do the data support the hypothesis that oxidative DNA damage caused by organochlorines affects breast cancer?

A study was conducted to test the hypothesis that oxidative DNA damage caused by exposure to organochlorines is an important risk factor in breast cancer. This is the first study that evaluates this hypothesis by measuring 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, polychlorinated biphenyl (PCB) congeners, and isomers of bis (4-chlorophenyl)-1,1,1-trichloroethane (DDT) and bis (4-chlorophenyl)-2,2,2-dichloroethane (DDE) in cancerous and noncancerous tissue. We measured these compounds in 44 primary tumors (cancerous) and 21 benign breast biopsy (noncancerous) tissues. Overall, no significant differences were observed in the level of the organochlorines between the tissues. The median concentration for 8-OHdG was 10.5 fmol/mg DNA (1.7/10⁵ deoxyguanosine residues), and 8.5 fmol/mg DNA (1.4/10⁵ deoxyguanosine residues) in cancerous and noncancerous tissue, respectively. These values are similar to background levels. No significant differences were observed in 8-OHdG levels in cancerous versus noncancerous tissue, and no correlation was demonstrated between the organochlorines and 8-OHdG. The data thus do not support the hypothesis that oxidative DNA damage caused by exposure to organochlorines is an important risk factor in breast cancer. Received: 7 December 2000/Accepted: 26 March 2001     

烹调油烟多环芳烃暴露与职业接触人群DNA氧化性损伤

目的 通过调查不同组别厨师和非暴露组尿中8-羟基脱氧鸟苷(8-OHdG)的排泄量,研究8-OHdG和1-羟基芘(1-OHP)之间的关系.方法 采集不同组别厨师组(n=86)和非暴露对照组(n=36)的尿液样本,观察对象均为年龄22～28岁男性,并有相似的吸烟习惯.在采样之前24 h内,以问卷调查的形式对研究对象的身体健康状况、职业史、吸烟习惯和酒精消费量进行评估.冷藏尿液样本,随后通过高效液相色谱法分析8-OHdG和1-OHP水平.结果 对照组尿液中8-OHdG的排泄量(平均1.2μmo1/mol肌酐,n=36)与厨房里有排烟设备运转的厨师组相似(平均1.5 μmol/mol肌酐,n=45).与对照组相比,接触油烟而排烟设备没有运转的厨师组,其尿8-OHdG的排泄量明显增加(平均2.3 μmol/mol 肌酐,n=18).经多元回归分析,尿ln 1-OHP和ln 8-OHdG的水平仍然呈明显的正相关.结论 接触油烟中的多环芳烃(PAH)或其他化合物可能导致DNA氧化损伤.     

8-Hydroxy-2′-deoxyguanosine as a marker of oxidative DNA damage related to occupational and environmental exposures

Oxidative DNA damage is considered to play an important role in pathophysiological processes, ageing and cancer. So far major interest has been on measuring 8-hydroxy-2′-deoxyguanosine (8-OHdG), the preferred methods relying on HPLC or GC-mass spectrometry. The high biological relevance of 8-OHdG is due to its ability to induce G→T transversions, which are among the most frequent somatic mutations found in human cancers. Effects of workplace exposures on the level of white blood cell 8-OHdG or urinary 8-OHdG have been reported with controversial results. Exposures examined include asbestos, azo-dyes, benzene, fine particulate matter (PM_2.5), glassworks, polycyclic aromatic hydrocarbons (PAHs), rubber manufacturing, silica, metals, styrene, toluene and xylenes. The available data indicate that there is still a lack of well established dose-response relations between occupational or environmental exposures and the induction of 8-OHdG. Smoking has been most consistently identified as a confounder for 8-OHdG, but various occupational studies did not reveal higher levels of 8-OHdG in smokers. Despite the conflicting results, the reported studies show promise for 8-OHdG as a biomarker of oxidative stress associated with chemical exposure. However, there are critical aspects related to the analytical challenge, artifactual production of 8-OHdG, inter- and intra-individual variation, confounding factors and inter-laboratory differences, implying that further work is needed to reach a consensus on the background level of 8-OHdG.     

饮水氯化消毒副产物MX诱导人胚肝细胞氧化应激及其与DNA损伤的关系

目的研究饮水氯化消毒副产物3-氯-4-二氯甲基-5-羟基-2(5氢)-呋喃酮(MX)对体外培养的人胚胎肝细胞(L-02细胞)氧化应激的诱导。方法MX设10、30、100和300μmol/L4个暴露浓度,二甲基亚砜(DMSO,10ml/L)为溶剂对照,将L-02细胞染毒24小时后,检测L-02细胞内脂质过氧化产物丙二醛(MDA)、还原型谷胱甘肽(GSH)和8羟基脱氧鸟苷(8-OHdG)的含量。结果与溶剂对照相比,30、100和300μmol/L的MX能明显增加L-02细胞MDA含量(P<0.05,P<0.001,P<0.001),100、300μmol/L的MX使L-02细胞GSH水平显著性降低(P<0.001,P<0.001)、8-OHdG含量显著性增加(P<0.05,P<0.01)。在MX0~300μmol/L浓度范围内,L-02细胞的MDA含量与8-OHdG含量呈正相关(r=0.767,P<0.01);GSH水平与8-OHdG含量呈负相关(r=0.761,P<0.01)。结论MX可诱导L-02细胞氧化应激,使其脂质过氧化反应增强、抗氧化作用降低、DNA氧化损伤增加。MX引发的脂质过氧化反应和抗氧化力下降是DNA氧化损伤的影响因素之一。