Watanabe Masumi, Suzuki Tetsuya
Laboratory of Food Wholesomeness and Soundness, Division of Life Sciences, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan.
Comp Biochem Physiol C Toxicol Pharmacol. 2002 Apr;131(4):491-500. doi: 10.1016/s1532-0456(02)00036-4.
Inorganic cadmium (Cd) causes cellular damage to eukaryotes and to tissues of higher organisms, including DNA strand breaks and intracellular membrane damage, as a result of reactive oxygen stress. We previously reported cadmium chloride (CdCl2)-induced abnormal cell morphologies in the unicellular eukaryote Euglena gracilis Z (a plant cell model) and its achlorophyllous mutant SMZ strain (an animal cell model). The present study was undertaken to examine whether exposure of both strains to CdCl2 would lead to similar cellular responses, especially with regard to reactive oxygen stress loading and cellular damage. The results indicate that CdCl2 exposure can induce morphological alteration, linked to reactive oxygen stress. Both E. gracilis Z and SMZ cells subjected to short-term, high-dose CdCl2 exposure showed long 'comet lengths' in the so-called 'Comet' assay, indicating DNA strand breaks. Similarly, short-term, high-dose CdCl(2)-exposed cells and CdCl(2)-induced morphologically altered cells showed intense fluorescence of dihydrofluorescein (HFLUOR) after incubation with dihydrofluorescein diacetate (HFLUOR-DA). Positive data on the generation and involvement of intracellular reactive oxygen species (ROS) were obtained from long-term, low-dose CdCl(2)-exposed E. gracilis Z and SMZ, by thiobarbituric acid (TBA)-malondialdehyde (MDA) complex analyses.
无机镉（Cd）会对真核生物以及高等生物的组织造成细胞损伤，包括DNA链断裂和细胞内膜损伤，这是活性氧应激的结果。我们之前报道过氯化镉（CdCl2）会在单细胞真核生物纤细裸藻Z（一种植物细胞模型）及其无叶绿素突变体SMZ菌株（一种动物细胞模型）中诱导异常细胞形态。本研究旨在检验这两种菌株暴露于CdCl2是否会导致相似的细胞反应，尤其是在活性氧应激负荷和细胞损伤方面。结果表明，CdCl2暴露可诱导与活性氧应激相关的形态改变。在所谓的“彗星”试验中，短期、高剂量暴露于CdCl2的纤细裸藻Z和SMZ细胞均显示出较长的“彗星长度”，表明存在DNA链断裂。同样，短期、高剂量暴露于CdCl2的细胞以及CdCl2诱导的形态改变细胞在与二氢荧光素二乙酸酯（HFLUOR-DA）孵育后显示出二氢荧光素（HFLUOR）的强烈荧光。通过硫代巴比妥酸（TBA）-丙二醛（MDA）复合物分析，从长期、低剂量暴露于CdCl2的纤细裸藻Z和SMZ中获得了关于细胞内活性氧（ROS）生成和参与的阳性数据。
