AIMS Burrowing mammals tend to be more hypoxia tolerant than non-burrowing mammals and rely less on increases in ventilation and more on decreases in metabolic rate to tolerate hypoxia. Naked mole-rats (Heterocephalus glaber, NMRs), eusocial mammals that live in large colonies, are among the most hypoxia-tolerant mammals, and rely almost solely on decreases in metabolism with little change in ventilation during hypoxia. We hypothesized that the remarkable hypoxia tolerance of NMRs is an evolutionarily conserved trait derived from repeated exposure to severe hypoxia owing to their burrow environment and eusocial colony organization. METHODS We used whole-body plethysmography and indirect calorimetry to measure the hypoxic ventilatory and metabolic responses of eight mole-rat species closely related to the NMR. RESULTS We found that all eight species examined had a strong tolerance to hypoxia, with most species tolerating 3 kPa O2 , Heliophobius emini tolerating 2 kPa O2 and Bathyergus suillus tolerating 5 kPa O2 . All species examined employed a combination of increases in ventilation and decreases in metabolism in hypoxia, a response midway between that of the NMR and that of other fossorial species (larger ventilatory responses, lesser reductions in metabolism). We found that eusociality is not fundamental to the physiological response to hypoxia of NMRs as Fukomys damarensis, another eusocial species, was among this group. CONCLUSIONS Our data suggest that, while the NMR is unique in the pattern of their physiological response to hypoxia, eight closely related mole-rat species share the ability to tolerate hypoxia like the current "hypoxia-tolerant champion," the NMR.

中文翻译：

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尽管严重缺氧的通气和代谢策略不同，但八种相关的非洲mole鼠物种的低氧耐受性可与裸mole鼠的低氧耐受性相提并论。

AIMS穴居哺乳动物比非穴居哺乳动物对低氧的耐受性更高，并且较少依赖通气量的增加，而更依赖于代谢率的降低来耐受低氧。裸mole鼠（Heterocephalus glaber，NMRs），生活在大殖民地的亲社会哺乳动物，是最耐缺氧的哺乳动物，并且几乎完全依赖于新陈代谢的降低，而在缺氧期间通气几乎没有变化。我们假设NMR的显着的低氧耐受性是一种进化保守的性状，源于其洞穴环境和社会集落组织，反复暴露于严重的低氧环境。方法我们使用全身体积描记法和间接量热法测量了8种与NMR密切相关的mole鼠物种的低氧通气和代谢反应。结果我们发现，所检查的所有八种物种均对缺氧具有较强的耐受性，其中大多数物种耐受3 kPa O2，埃利俄比俄虫（Heliophobius emini）耐受2 kPa O2，而枯草芽孢杆菌（Bathyergus suillus）耐受5 kPa O2。在低氧条件下，所检查的所有物种均采用通气增加和新陈代谢降低的组合，这是NMR与其他基础物种之间的响应（较大的通气响应，较小的代谢降低）。我们发现，礼节性并不是NMR缺氧的生理反应的基础，因为另一种正常社会种Fukomys damarensis属于这一类。结论我们的数据表明，尽管NMR在其对缺氧的生理反应模式中是独特的，但八种密切相关的mole鼠物种具有耐受缺氧的能力，就像目前的“