Cebulska-Wasilewska Antonina, Panek Agnieszka, Zabiński Zbigniew, Moszczyński Paulin
Z Zakładu Biologii Radiacyjnej i Srodowiskowej, Instytutu Fizyki Jadrowej Polskiej Akademii Nauk w Krakowie.
Med Pr. 2005;56(4):303-10.
The aim of the study was to compare the levels of DNA and cytogenetic damage in lymphocytes from donors occupationally exposed to mercury vapors and from matched controls as well as their cellular susceptibility to radiation and capabilities to repair DNA damage induced by UV-C or X-ray exposures in vitro.
To estimate cytogenetic damage, the analysis of sister chromatid exchange frequency (SCE) was used, and to detect DNA damage the alkaline version of single cell gel electrophoresis (SCGE) was applied. To analyze cellular susceptibility, lymphocytes were exposed to 6 J/m2 of UV-C or irradiated with 2 Gy of X-rays. After challenging exposures, cells were incubated for 2 h with or without the presence of cellular mitogen (phytohemagglutinin--PHA).
The study did not show statistically significant differences either between the groups, levels of DNA damage (measured as the percentage of cells with comets or comet tail moments), or sister chromatid exchanges. Neither were there significant differences in the levels of DNA damage (measured as tail moment and comet length) detected in UV-C exposed lymphocytes after 2 h incubation in the presence or in the absence of PHA stimulating cells and in the susceptibility to X-ray radiation of lymphocytes between the groups of non-exposed persons and those occupationally exposed to mercury vapors. In the group exposed to mercury vapors, however, statistically significantly higher levels of non-repaired DNA damage measured in X-ray irradiated lymphocytes after 2 h of incubation, with or without the presence of mitogen were observed compared to controls. Significant differences were observed in all types of DNA damage measures (comet tail length, % of DNA, in the comet and comet tail moments). As a result, lymphocytes of donors exposed to mercury vapors showed a statistically lower repair efficiency of X-ray-induced DNA damage both in non-stimulated (70.0% for the exposed, 85.7% for the non-exposed) and stimulated (84.0% for the exposed and 90.4% for the non-exposed) lymphocytes. Cellular DNA repair efficiency decreased with increasing number of years of occupational exposure. Statistically significant DNA repair deficiency in the donors exposed to mercury vapors was also observed when the groups were stratified to smokers and non-smokers.
本研究的目的是比较职业性接触汞蒸气的供体淋巴细胞与配对对照淋巴细胞中的DNA和细胞遗传学损伤水平，以及它们在体外对辐射的细胞敏感性和修复紫外线-C（UV-C）或X射线照射诱导的DNA损伤的能力。
为评估细胞遗传学损伤，采用姐妹染色单体交换频率（SCE）分析；为检测DNA损伤，应用单细胞凝胶电泳（SCGE）的碱性版本。为分析细胞敏感性，淋巴细胞分别接受6 J/m²的UV-C照射或2 Gy的X射线辐照。在挑战性照射后，细胞在有或无细胞促有丝分裂原（植物血凝素——PHA）存在的情况下孵育2小时。
该研究未显示两组之间在DNA损伤水平（以彗星状细胞或彗星尾矩的细胞百分比衡量）或姐妹染色单体交换方面存在统计学显著差异。在有或无PHA刺激细胞孵育2小时后，UV-C照射的淋巴细胞中检测到的DNA损伤水平（以尾矩和彗星长度衡量），以及未接触者组和职业性接触汞蒸气者组淋巴细胞对X射线辐射的敏感性，也均无显著差异。然而，在接触汞蒸气的组中，与对照组相比，在有或无促有丝分裂原存在的情况下孵育2小时后，X射线辐照的淋巴细胞中测得的未修复DNA损伤水平在统计学上显著更高。在所有类型的DNA损伤测量指标（彗星尾长度、彗星中的DNA百分比和彗星尾矩）上均观察到显著差异。结果，接触汞蒸气的供体淋巴细胞在未刺激（接触组为70.0%，未接触组为85.7%）和刺激（接触组为84.0%，未接触组为90.4%）的淋巴细胞中，对X射线诱导的DNA损伤的修复效率在统计学上均较低。细胞DNA修复效率随职业接触年限的增加而降低。当按吸烟者和非吸烟者对组进行分层时，在接触汞蒸气的供体中也观察到统计学显著的DNA修复缺陷。
