State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, The Research Center for Laboratory Animal Science, School of Life Sciences, Inner Mongolia University, Hohhot, People's Republic of China.
Inner Mongolia People's Hospital, Hohhot, Inner Mongolia, People's Republic of China.
Toxicology. 2019 Nov 1;427:152284. doi: 10.1016/j.tox.2019.152284. Epub 2019 Aug 30.
Sodium nitrite (NaNO) is an industrial chemical that is frequently used as a food additive to prevent botulism and enhance glossiness, such as curing meat. In addition, in some regions, water source NaNO concentrations exceed standard regulatory levels. Whether the excessive intake of NaNO has toxic effects on female fertility and fetal development remain unknown. In this study, we administered ICR mice control saline, low-dose NaNO (60 mg/kg/day), or high-dose NaNO (120 mg/kg/day) by intragastric gavage for 21 days. We then assessed oocyte morphology, spindle-chromosome dynamics, mitochondrial distribution, ATP content, apoptotic cell numbers, DNA damage levels, histone modifications, reactive oxygen species (ROS) levels, and offspring survival. Results showed that NaNO treatment decreased oocyte number, impaired polar body extrusion, and increased zona pellucida thickness in oocytes. Furthermore, NaNO disrupted MII spindle integrity, caused abnormal mitochondrial distribution, decreased ATP content, and increased levels of ROS and H3K4me2. Moreover, the number of oocytes in early stages of apoptosis and with levels of DNA damage increased in NaNO-treated mice along with decreased offspring numbers and survival rates. We demonstrated the negative effects of NaNO on female reproductive abilities in mice.
亚硝酸钠（NaNO）是一种工业化学物质，常用于食品添加剂，以防止肉毒中毒和增加光泽度，如腌制肉类。此外，在一些地区，水源中的 NaNO 浓度超过了标准监管水平。过量摄入 NaNO 是否对女性生育能力和胎儿发育有不良影响尚不清楚。在这项研究中，我们通过灌胃给 ICR 小鼠给予生理盐水、低剂量 NaNO（60mg/kg/天）或高剂量 NaNO（120mg/kg/天），连续 21 天。然后，我们评估了卵母细胞形态、纺锤体-染色体动力学、线粒体分布、ATP 含量、凋亡细胞数量、DNA 损伤水平、组蛋白修饰、活性氧（ROS）水平和后代存活率。结果表明，NaNO 处理降低了卵母细胞数量，损害了极体的挤出，并增加了卵母细胞的透明带厚度。此外，NaNO 破坏了 MII 纺锤体的完整性，导致线粒体分布异常，ATP 含量降低，ROS 和 H3K4me2 水平升高。此外，NaNO 处理组中早期凋亡卵母细胞的数量和 DNA 损伤水平增加，同时后代数量和存活率降低。我们证明了 NaNO 对小鼠生殖能力的负面影响。
