Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
Korea Basic Science Institute, Seoul Center, Seoul 02841, South Korea.
J Hazard Mater. 2020 Jun 5;391:122196. doi: 10.1016/j.jhazmat.2020.122196. Epub 2020 Jan 30.
The toxicity of arsenic (As) has been reported to be different depending on their chemical forms. However, its toxicity mechanisms largely remain unknown. In this study, to investigate toxicity mechanism of As in marine zooplanktons, namely, the rotifer Brachionus plicatilis and the copepod Paracyclopina nana, metabolites of As were analyzed by using a high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry with in vivo toxicity and antioxidant responses in response to inorganic As, including arsenate (As) and arsenite (As). While As was more toxic than As in both organisms, the rotifer B. plicatilis exhibited stronger tolerance, compared to the copepod P. nana. The As speciation analysis revealed differences in biotransformation processes in two species with B. plicatilis having a more simplified process than P. nana, contributing to a better tolerance against As in the rotifer B. plicatilis compared to P. nana. Moreover, the levels of GSH content and the regulation of omega class glutathione S-transferases were different in response to oxidative stress between B. plicatilis and P. nana. These results suggest that the rotifer B. plicatilis has a unique survival strategy with more efficient biotransformation and antioxidant responses, compared to P. nana, conferring higher tolerance to As.
砷（As）的毒性据报道因其化学形态的不同而有所差异。然而，其毒性机制在很大程度上仍然未知。在这项研究中，为了研究海洋浮游动物（即褶皱臂尾轮虫和近邻新镖水蚤）中砷的毒性机制，我们采用高效液相色谱-电感耦合等离子体质谱联用技术，分析了砷的代谢产物，并检测了无机砷（包括砷酸盐（As）和亚砷酸盐（As））对其体内毒性和抗氧化反应的影响。虽然砷在这两种生物中的毒性均大于砷，但轮虫褶皱臂尾轮虫比桡足类近邻新镖水蚤表现出更强的耐受性。砷形态分析揭示了两种生物在生物转化过程中的差异，轮虫褶皱臂尾轮虫的转化过程比桡足类近邻新镖水蚤更简单，这有助于轮虫褶皱臂尾轮虫比桡足类近邻新镖水蚤对砷具有更好的耐受性。此外，在应对氧化应激时，轮虫褶皱臂尾轮虫和桡足类近邻新镖水蚤的 GSH 含量水平和ω 类谷胱甘肽 S-转移酶的调控存在差异。这些结果表明，与桡足类近邻新镖水蚤相比，轮虫褶皱臂尾轮虫具有独特的生存策略，其生物转化和抗氧化反应效率更高，从而对砷具有更高的耐受性。
