College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, Hubei, 430070, China.
J Aquat Anim Health. 2022 Jun;34(2):58-68. doi: 10.1002/aah.10149. Epub 2022 Apr 16.
To evaluate the effects of nitrite on the oxidative damage of blood cells of Grass Carp Ctenopharyngodon idella, the isolated hemocytes were exposed to nitrite (0, 1, 10, or 100 mg/L) for up to 24 h. Hemoglobin (Hb) and methemoglobin (MetHb) concentrations, reactive oxygen species (ROS) and malondialdehyde (MDA) levels, mitochondrial membrane potential (∆Ψm), and antioxidant enzyme activity were assayed to assess hematological parameters and the antioxidant defense mechanism. Results showed a remarkable decrease in Hb concentration with increasing nitrite concentration after a 24-h exposure, while the MetHb concentration increased significantly in nitrite exposure groups. The levels of ROS, ∆Ψm, and MDA increased to varying degrees with increases in nitrite exposure concentration and time. The total antioxidant capacity, catalase (CAT) activity, glutathione peroxidase (GPx) activity, and glutathione content showed a trend of rising initially and then decreasing with prolonged exposure time. Superoxide dismutase (SOD) activity was higher in the 1-mg/L nitrite exposure group and lower in the 100-mg/L group than in the control. The relative messenger RNA expression ratios of cat, sod1, and gpx were up-regulated significantly in the 1- and 10-mg/L groups and then declined in the 100-mg/L group. Therefore, it can be concluded that nitrite exposure activates the antioxidant defense mechanism of Grass Carp hemocytes and that the balance of oxidant-antioxidant homeostasis will be undermined by higher nitrite doses or longer exposure periods.
为了评估亚硝酸盐对草鱼血细胞氧化损伤的影响，将分离的血红细胞暴露于亚硝酸盐（0、1、10 或 100mg/L）中长达 24 小时。血红蛋白（Hb）和高铁血红蛋白（MetHb）浓度、活性氧（ROS）和丙二醛（MDA）水平、线粒体膜电位（∆Ψm）以及抗氧化酶活性用于评估血液学参数和抗氧化防御机制。结果表明，在 24 小时暴露后，随着亚硝酸盐浓度的增加，Hb 浓度显著下降，而 MetHb 浓度在亚硝酸盐暴露组中显著增加。随着亚硝酸盐暴露浓度和时间的增加，ROS、∆Ψm 和 MDA 的水平不同程度地增加。总抗氧化能力、过氧化氢酶（CAT）活性、谷胱甘肽过氧化物酶（GPx）活性和谷胱甘肽含量随着暴露时间的延长呈先升高后降低的趋势。超氧化物歧化酶（SOD）活性在 1mg/L 亚硝酸盐暴露组中较高，在 100mg/L 组中较低，低于对照组。CAT、sod1 和 gpx 的相对信使 RNA 表达比值在 1mg/L 和 10mg/L 组中显著上调，然后在 100mg/L 组中下降。因此，可以得出结论，亚硝酸盐暴露激活了草鱼血红细胞的抗氧化防御机制，而更高的亚硝酸盐剂量或更长的暴露时间会破坏氧化还原平衡的稳态。
