Shekhovtsov Sergei V, Vorontsova Yana L, Slepneva Irina A, Smirnov Dmitry N, Khrameeva Ekaterina E, Shatunov Alexey, Poluboyarova Tatiana V, Bulakhova Nina A, Meshcheryakova Ekaterina N, Berman Daniil I, Glupov Viktor V
Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Institute of Biological Problems of the North, Far East Branch of the Russian Academy of Sciences, Magadan, 630058, Russia.
Biochemistry (Mosc). 2024 Mar;89(3):441-450. doi: 10.1134/S0006297924030052.
The Siberian frog Rana amurensis has a uniquely high tolerance to hypoxia among amphibians, as it is able to withstand several months underwater with almost no oxygen (0.2 mg/liter) vs. several days for other studied species. Since it was hypothesized that hypoxia actives the antioxidant defense system in hypoxia-tolerant animals, one would expect similar response in R. amurensis. Here, we studied the effect of hypoxia in the Siberian frog based on the transcriptomic data, activities of antioxidant enzyme, and content of low-molecular-weight antioxidants. Exposure to hypoxia upregulated expression of three relevant transcripts (catalase in the brain and two aldo-keto reductases in the liver). The activities of peroxidase in the blood and catalase in the liver were significantly increased, while the activity of glutathione S-transferase in the liver was reduced. The content of low-molecular-weight antioxidants (thiols and ascorbate) in the heart and liver was unaffected. In general, only a few components of the antioxidant defense system were affected by hypoxia, while most remained unchanged. Comparison to other hypoxia-tolerant species suggests species-specific adaptations to hypoxia-related ROS stress.
西伯利亚蛙（Rana amurensis）是两栖动物中对缺氧具有独特高耐受性的物种，它能够在水下存活数月，几乎没有氧气（0.2 毫克/升），而其他研究的物种只能存活数天。由于假设缺氧会激活耐缺氧动物的抗氧化防御系统，因此人们预计西伯利亚蛙会有类似的反应。在这里，我们基于转录组数据、抗氧化酶活性和低分子量抗氧化剂含量来研究缺氧对西伯利亚蛙的影响。缺氧暴露会上调三种相关转录本（大脑中的过氧化氢酶和肝脏中的两种醛酮还原酶）的表达。血液中的过氧化物酶和肝脏中的过氧化氢酶活性显著增加，而肝脏中的谷胱甘肽 S-转移酶活性降低。心脏和肝脏中低分子量抗氧化剂（巯基和抗坏血酸）的含量不受影响。总的来说，只有少数抗氧化防御系统的成分受到缺氧的影响，而大多数成分保持不变。与其他耐缺氧物种的比较表明，物种对与缺氧相关的 ROS 应激具有特异性适应。
