Extreme hypoxemic tolerance and blood oxygen depletion in diving elephant seals
Extreme hypoxemic tolerance and blood oxygen depletion in diving elephant seals
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DOI：
10.1152/ajpregu.00247.2009
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发表时间：
2009-10-01
影响因子：
2.8
通讯作者：
Ponganis, Paul J.
中科院分区：
文献类型：
--
作者：
Meir, Jessica U.;Champagne, Cory D.;Ponganis, Paul J.
朱梅，香槟CD， Costa DP, Williams CL, Ponganis PJ。潜水象海豹的极度低氧耐受性和血氧消耗。[J] .中国生物医学工程学报，2016,31(2):444 - 444。首次发表于2009年7月29日；doi: 10.1152 / ajpregu.00247.2009。当氧（O-2）供应有限时，维持有氧代谢的物种是研究缺氧耐受机制的理想模型。北象海豹（miounga angustirostris）的重复、长时间潜水一直是一个生理谜，因为O-2储存似乎不足以维持有氧代谢。我们通过以下方法评估低氧耐量和血液O-2消耗：1)在海象潜水期间使用PO2/温度记录仪测量动脉和静脉O-2分压（PO2）， 2)表征该物种的O-2血红蛋白（O-2-Hb）解解曲线，3)将解解曲线应用于PO2剖面以获得%Hb饱和度（SO2），以及4)计算潜水期间血液O-2储存消耗。通过高静脉O-2负荷和潜水期间几乎完全耗尽血液O-2储存，实现了O-2储存的优化，净O-2含量消耗值高达91%（动脉）和100%（静脉）。在常规潜水（bbb10 min）中，Pv（O2）和Pa-O2值分别达到2-10和12-23 mmHg。这相当于SO2为1-26%，O-2含量为0.3（静脉）和2.7 ml O-2/dl（动脉），表现出显著的低氧耐受性，因为PaO2几乎相当于海豹的动脉低氧阈值。仅血液O-2储存对代谢率的贡献几乎等于静息代谢率，平均温度保持在37摄氏度附近。这些数据表明，海象在潜水期间通常耐受极端低氧血症，以充分利用血液O-2储存并最大限度地延长有氧潜水时间。
Meir JU, Champagne CD, Costa DP, Williams CL, Ponganis PJ. Extreme hypoxemic tolerance and blood oxygen depletion in diving elephant seals. Am J Physiol Regul Integr Comp Physiol 297: R927-R939, 2009. First published July 29, 2009; doi: 10.1152/ajpregu.00247.2009.-Species that maintain aerobic metabolism when the oxygen (O-2) supply is limited represent ideal models to examine the mechanisms underlying tolerance to hypoxia. The repetitive, long dives of northern elephant seals (Mirounga angustirostris) have remained a physiological enigma as O-2 stores appear inadequate to maintain aerobic metabolism. We evaluated hypoxemic tolerance and blood O-2 depletion by 1) measuring arterial and venous O-2 partial pressure (PO2) during dives with a PO2/temperature recorder on elephant seals, 2) characterizing the O-2 hemoglobin (O-2-Hb) dissociation curve of this species, 3) applying the dissociation curve to PO2 profiles to obtain %Hb saturation (SO2), and 4) calculating blood O-2 store depletion during diving. Optimization of O-2 stores was achieved by high venous O-2 loading and almost complete depletion of blood O-2 stores during dives, with net O-2 content depletion values up to 91% (arterial) and 100% (venous). In routine dives (>10 min) Pv(O2) and Pa-O2 values reached 2-10 and 12-23 mmHg, respectively. This corresponds to SO2 of 1-26% and O-2 contents of 0.3 (venous) and 2.7 ml O-2/dl blood (arterial), demonstrating remarkable hypoxemic tolerance as PaO2 is nearly equivalent to the arterial hypoxemic threshold of seals. The contribution of the blood O-2 store alone to metabolic rate was nearly equivalent to resting metabolic rate, and mean temperature remained near 37 degrees C. These data suggest that elephant seals routinely tolerate extreme hypoxemia during dives to completely utilize the blood O-2 store and maximize aerobic dive duration.