Bittrich H, Mátzig A K, Kráker I, Appel K E
Max von Pettenkofer-Institute, Federal Health Office, Berlin, Germany.
Chem Biol Interact. 1993 Mar;86(3):199-211. doi: 10.1016/0009-2797(93)90098-j.
Recently, we were able to show that nitrogen dioxide (NO2), a strong oxidant, induced DNA single strand breaks (SSBs) in V79 cells. Possibly, special scavengers, e.g. antioxidative vitamins, may protect cells from NO2-induced damage. Therefore, the effect of various tocopherols, beta-carotene, retinol, and ascorbic acid on NO2-induced SSBs in V79 cells was investigated. Cells were preincubated with vitamins and treated for 10 min with 200 ppm NO2. The rate of SSBs was measured by the alkaline elution assay, the amount of DNA by a fluorimetric assay. Micromolar concentrations of d-gamma-tocopherol inhibited the rate of NO2-induced SSBs by 40%, beta-carotene and ascorbic acid by 25%. None of these vitamins had any effects on DNA or the viability of cells. When incubating the cells with retinol in a medium with pH 8.5, this vitamin inhibited NO2-induced SSBs, reducing them by 35%. However, in high concentrations, retinol itself induced SSBs and influenced cell viability. The results are discussed with regard to many toxic effects of NO2.
最近，我们能够证明，强氧化剂二氧化氮（NO₂）可在V79细胞中诱导DNA单链断裂（SSB）。特殊的清除剂，如抗氧化维生素，可能会保护细胞免受NO₂诱导的损伤。因此，我们研究了各种生育酚、β-胡萝卜素、视黄醇和抗坏血酸对V79细胞中NO₂诱导的SSB的影响。细胞先用维生素进行预孵育，然后用200 ppm的NO₂处理10分钟。通过碱性洗脱测定法测量SSB的速率，通过荧光测定法测量DNA的量。微摩尔浓度的d-γ-生育酚可使NO₂诱导的SSB速率降低40%，β-胡萝卜素和抗坏血酸可使其降低25%。这些维生素对DNA或细胞活力均无任何影响。当在pH 8.5的培养基中用视黄醇孵育细胞时，这种维生素可抑制NO₂诱导的SSB，使其减少35%。然而，高浓度的视黄醇本身会诱导SSB并影响细胞活力。我们结合NO₂的许多毒性作用对结果进行了讨论。
