Institute of Cytology and Genetics SB RAS, Lavrentieva av. 10, Novosibirsk, 630090, Russia.
Institute of the Biological Problems of the North FEB RAS, Portovaya 18, Magadan, 685000, Russia.
J Comp Physiol B. 2024 Dec;194(6):855-867. doi: 10.1007/s00360-024-01584-y. Epub 2024 Sep 18.
The Pallas' spadefoot Pelobates vespertinus is a frog species native to eastern Europe and west Siberia. This species resists harsh winter conditions by moving up to 2 m underground. This amphibian is the first species known to withstand extreme air hypoxia. In this study, we investigated the metabolome of liver, heart, and brain of the Pallas' spadefoot after a month-long exposure of hypoxia, with oxygen levels reduced to approximately one-tenth of the air normal content. Surprisingly, our findings revealed a limited impact of hypoxia on the metabolomic profiles. Concentrations of glycolysis end products (lactate and alanine) increased only slightly compared to other amphibians under hypoxia, and no accumulation of succinate was observed. Furthermore, there were no notable changes in the content of adenosine phosphates. These results are consistent with a previous study, which indicated that the Pallas' spadefoot possesses relatively small glycogen and fat reserves before the winter compared to other frogs. It appears that this species conserves energy during winter by minimizing its metabolic activity. These findings corroborated the hypothesis that the survival of P. vespertinus under hypoxic conditions primarily relies on metabolic suppression rather than substantial energy reserves.
巴氏蟾蛙 Pelobates vespertinus 是一种原产于东欧和西西伯利亚的蛙类。为了抵御严寒的冬季，这种蛙类可以在地下移动 2 米之深。巴氏蟾蛙是已知的第一种能够耐受极端缺氧空气的物种。在这项研究中，我们研究了巴氏蟾蛙在长达一个月的缺氧暴露后，其肝脏、心脏和大脑的代谢组。在实验中，氧气水平被降低到正常空气含量的约十分之一。令人惊讶的是，我们的发现表明，缺氧对代谢组图谱的影响有限。与其他在缺氧条件下的两栖动物相比，糖酵解终产物（乳酸和丙氨酸）的浓度仅略有增加，并且没有观察到琥珀酸的积累。此外，腺苷磷酸的含量也没有明显变化。这些结果与之前的一项研究一致，该研究表明，与其他青蛙相比，巴氏蟾蛙在冬季之前的糖原和脂肪储备相对较少。看来，这种物种通过最小化其代谢活动来在冬季保存能量。这些发现证实了这样一种假设，即在缺氧条件下，巴氏蟾蛙的生存主要依赖于代谢抑制，而不是大量的能量储备。
