低氧水平有助于防止急性变暖对鱼类线粒体效率的不利影响

Low oxygen levels can help to prevent the detrimental effect of acute warming on mitochondrial efficiency in fish.

Keywords：ATP/O ratio, Dissolved oxygen, Mitochondrial respiratory capacities, Temperature

关键词： ATP/O 比、溶解氧、线粒体呼吸能力、温度
作者：Thoral Elisa , Roussel Damien , Chinopoulos Christos , Teulier Loic , Salin Karine

出版期刊：《《Biol. Lett. 》（2021年）

Abstract：

Aerobic metabolism of aquatic ectotherms is highly sensitive to fluctuating climates. Many mitochondrial traits exhibit phenotypic plasticity in response to acute variations in temperature and oxygen availability. These responses are critical for understanding the effects of environmental variations on aquatic ectotherms' performance. Using the European seabass, Dicentrarchus labrax, we determined the effects of acute warming and deoxygenation in vitro on mitochondrial respiratory capacities and mitochondrial efficiency to produce ATP (ATP/O ratio). We show that acute warming reduced ATP/O ratio but deoxygenation marginally raised ATP/O ratio, leading to a compensatory effect of low oxygen availability on mitochondrial ATP/O ratio at high temperature. The acute effect of warming and deoxygenation on mitochondrial efficiency might be related to the leak of protons across the mitochondrial inner membrane, as the mitochondrial respiration required to counteract the proton leak increased with warming and decreased with deoxygenation. Our study underlines the importance of integrating the combined effects of temperature and oxygen availability on mitochondrial metabolism. Predictions on decline in performance of aquatic ectotherms owing to climate change may not be accurate, since these predictions typically look at respiratory capacity and ignore efficiency of ATP production. 

文章摘要：

水生变温动物的有氧代谢对气候波动高度敏感。许多线粒体性状表现出表型可塑性，以响应温度和氧气可用性的剧烈变化。这些反应对于了解环境变化对水生等温鱼表现的影响至关重要。使用欧洲鲈鱼，Dicentrarchus labrax ，我们在体外确定了急性变暖和脱氧的影响线粒体呼吸能力和线粒体产生 ATP 的效率（ATP/O 比率）。我们表明，急性变暖降低了 ATP/O 比率，但脱氧略微提高了 ATP/O 比率，导致高温下低氧可用性对线粒体 ATP/O 比率的补偿作用。变暖和脱氧对线粒体效率的急性影响可能与质子通过线粒体内膜的泄漏有关，因为抵消质子泄漏所需的线粒体呼吸随着变暖而增加而随着脱氧而减少。我们的研究强调了整合温度和氧气可用性对线粒体代谢的综合影响的重要性。由于气候变化导致水生变温动物性能下降的预测可能不准确。

点击链接即可查看和下载文章：https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8086979/pdf/rsbl.2020.0759.pdf

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