Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China.
Can J Physiol Pharmacol. 2019 Oct;97(10):980-988. doi: 10.1139/cjpp-2019-0092. Epub 2019 May 28.
The degree and duration of chemical hypoxia induced by sodium dithionite (NaSO) have not been reported. It is not yet clear how much reduction in the O concentration (physical hypoxia) can lead to hypoxia in cultured cardiomyocytes. In this study, oxygen microelectrodes were used to measure changes in the O concentration in media containing different concentrations of NaSO. Then, hypoxic effects of 0.8, 1.0, and 2.0 mM NaSO or 1%, 3%, and 5% O in cultured cardiomyocytes from neonatal rats were observed and compared. The results showed that the O concentration failed to remain constant by NaSO treatment during the 180-minute observation period. Only the 2.0 mM NaSO group significantly increased the expression of hypoxia-inducible factor 1α (HIF-1α) and hypoxic responses. Notably, 3% O only significantly increased the expression of HIF-1α in cardiomyocytes, while 1% O not only increased the expression of HIF-1α but also increased the apoptotic rate in cardiomyocytes. These results suggest that NaSO is not suitable for establishing a hypoxic model in cultured neonatal rat cardiomyocytes, and neonatal rat cardiomyocytes cultured at or below 1% O induced significant hypoxic effects, which can be used as a starting O concentration for establishing a hypoxic cell model.
连二亚硫酸钠（NaSO）诱导的化学缺氧程度和持续时间尚未报道。目前尚不清楚氧浓度（物理缺氧）降低多少会导致培养的心肌细胞缺氧。在这项研究中，使用氧微电极测量了含有不同浓度 NaSO 的培养基中氧浓度的变化。然后，观察并比较了 0.8、1.0 和 2.0mM NaSO 或 1%、3%和 5%O 对新生大鼠心肌细胞的缺氧作用。结果表明，在 180 分钟的观察期内，NaSO 处理未能使氧浓度保持恒定。只有 2.0mM NaSO 组显著增加了缺氧诱导因子 1α（HIF-1α）的表达和缺氧反应。值得注意的是，3%O 仅显著增加了心肌细胞中 HIF-1α 的表达，而 1%O 不仅增加了 HIF-1α 的表达，还增加了心肌细胞的凋亡率。这些结果表明，NaSO 不适合用于建立培养的新生大鼠心肌细胞缺氧模型，并且培养在 1%O 或更低水平的新生大鼠心肌细胞会引起明显的缺氧作用，可作为建立缺氧细胞模型的起始氧浓度。
