Dahl Helge-Andre, Johansen Anette, Nilsson Göran E, Lefevre Sjannie
Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0371 Oslo, Norway.
Metabolites. 2021 Jul 1;11(7):435. doi: 10.3390/metabo11070435.
The anoxia-tolerant crucian carp () has been studied in detail for numerous years, with particular focus on unravelling the underlying physiological mechanisms of anoxia tolerance. However, relatively little work has been focused on what occurs beyond anoxia, and often the focus is a single organ or tissue type. In this study, we quantified more than 100 metabolites by capillary electrophoresis-mass spectrometry (CE-MS) in brain, heart, liver, and blood plasma from four experimental groups, being normoxic (control) fish, anoxia-exposed fish, and two groups that had been exposed to anoxia followed by reoxygenation for either 3 h or 24 h. The heart, which maintains cardiac output during anoxia, unexpectedly, was slower to recover compared to the brain and liver, mainly due to a slower return to control concentrations of the energy-carrying compounds ATP, GTP, and phosphocreatine. Crucian carp accumulated amino acids in most tissues, and also surprisingly high levels of succinate in all tissues investigated during anoxia. Purine catabolism was enhanced, leading to accumulation of uric acid during anoxia and increasing urea formation that continued into 24 h of reoxygenation. These tissue-specific differences in accumulation and distribution of the metabolites may indicate an intricate system of transport between tissues, opening for new avenues of investigation of possible mechanisms aimed at reducing the generation of reactive oxygen species (ROS) and resultant tissue damage during reoxygenation.
耐缺氧鲫鱼已经被详细研究了很多年，尤其专注于揭示其耐缺氧的潜在生理机制。然而，相对较少的工作集中在缺氧之后发生了什么，而且通常关注的是单一器官或组织类型。在本研究中，我们通过毛细管电泳-质谱联用（CE-MS）对四个实验组的脑、心脏、肝脏和血浆中的100多种代谢物进行了定量分析，这四个实验组分别是常氧（对照）鱼、缺氧处理的鱼，以及两组先经历缺氧再复氧3小时或24小时的鱼。在缺氧期间维持心输出量的心脏，出人意料地比脑和肝脏恢复得慢，主要原因是携带能量的化合物ATP、GTP和磷酸肌酸恢复到对照浓度的速度较慢。鲫鱼在大多数组织中积累氨基酸，并且在缺氧期间所有被研究的组织中琥珀酸水平也出奇地高。嘌呤分解代谢增强，导致缺氧期间尿酸积累，并使尿素形成增加，这种情况一直持续到复氧24小时。这些代谢物在积累和分布上的组织特异性差异可能表明组织间存在一个复杂的转运系统，为研究旨在减少复氧期间活性氧（ROS）生成及由此导致的组织损伤的可能机制开辟了新途径。
