Daube H, Scherer G, Riedel K, Ruppert T, Tricker A R, Rosenbaum P, Adlkofer F
Universität-Frauenklinik und Poliklinik, Homburg/Saar, Germany.
J Cancer Res Clin Oncol. 1997;123(3):141-51. doi: 10.1007/BF01214666.
The DNA adduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been widely used as a biomarker for oxidative stress. Bulky DNA adducts, which are detectable by the 32P-postlabelling method, provide evidence for exposure to and metabolic activation of large, mainly apolar compounds, e.g. polycyclic aromatic hydrocarbons. We determined both types of adducts in placental tissues of 30 term pregnancies and related the adduct levels to the exposure to tobacco smoke and the plasma antioxidant status. Urine and plasma continine concentrations were used to select 10 nonsmokers, 9 nonsmokers exposed to environmental tobacco smoke (ETS) and 11 smoking women. Placental levels of 8-OHdG were 0.84 +/- 0.11, 0.90 +/- 0.21 and 0.83 +/- 0.20/10(5) deoxyguanosine bases (dG) for nonsmokers, nonsmokers exposed to ETS and smokers, respectively. The differences between the groups were not significant. Smoking women had significantly lower plasma vitamin C and beta-carotene concentrations than nonsmoking women or nonsmoking women exposed to environmental tobacco smoke. The 8-OHdG adduct level in placental DNA was inversely correlated with the plasma vitamin E concentration (r = -0.47, P < 0.05). There was no association between placental 8-OHdG adducts and vitamin A, C and beta-carotene in plasma. In total, 15 different adducts could be identified in the 30 placenta samples by the 32P-postlabelling method. There was a strong inter-individual variation in both the number of adducts and adduct intensities. No smoking-related or vitamin-related effects on adduct patterns or intensities were found. Our findings suggests that, within the limits of the methods used, tobacco smoke exposure during pregnancy does not lead to a measurable increase in placental DNA adduct levels and that vitamin E appears to have a protective effect on placental 8-OHdG formation.
DNA加合物8-羟基-2'-脱氧鸟苷（8-OHdG）已被广泛用作氧化应激的生物标志物。大的DNA加合物可通过32P后标记法检测到，它为接触大型主要是非极性化合物（如多环芳烃）及其代谢活化提供了证据。我们测定了30例足月妊娠胎盘组织中的这两种加合物，并将加合物水平与接触烟草烟雾情况及血浆抗氧化状态相关联。尿和血浆中可替宁浓度用于挑选出10名不吸烟者、9名接触环境烟草烟雾（ETS）的不吸烟者和11名吸烟女性。不吸烟者、接触ETS的不吸烟者和吸烟者胎盘组织中8-OHdG的水平分别为0.84±0.11、0.90±0.21和0.83±0.20/10(5)脱氧鸟苷碱基（dG）。各组之间的差异不显著。吸烟女性的血浆维生素C和β-胡萝卜素浓度显著低于不吸烟女性或接触环境烟草烟雾的不吸烟女性。胎盘DNA中的8-OHdG加合物水平与血浆维生素E浓度呈负相关（r = -0.47，P < 0.05）。胎盘8-OHdG加合物与血浆中的维生素A、C和β-胡萝卜素之间无关联。通过32P后标记法在30份胎盘样本中总共鉴定出15种不同的加合物。加合物的数量和强度在个体间均存在很大差异。未发现吸烟或维生素对加合物模式或强度有相关影响。我们的研究结果表明，在所使用方法的限度内，孕期接触烟草烟雾不会导致胎盘DNA加合物水平出现可测量的增加，并且维生素E似乎对胎盘8-OHdG的形成具有保护作用。
