Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review
Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review
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TY - JOUR
T1 - High blood oxygen affinity in the air-breathing swamp eel Monopterus albus
AU - Damsgaard, Christian
AU - Findorf, Inge
AU - Helbo, Signe
AU - Kocagoz, Yigit
AU - Buchanan, Rasmus
AU - Huong, Do Thi Thanh
AU - Weber, Roy E.
AU - Fago, Angela
AU - Bayley, Mark
AU - Wang, Tobias
N1 - Copyright © 2014 Elsevier Inc. All rights reserved.
PY - 2014/12
Y1 - 2014/12
N2 - The Asian swamp eel (Monopterus albus, Zuiew 1793) is a facultative air-breathing fish with reduced gills. Previous studies have shown that gas exchange seems to occur across the epithelium of the buccopharyngeal cavity, the esophagus and the integument, resulting in substantial diffusion limitations that must be compensated by adaptations in others steps of the O₂ transport system to secure adequate O₂ delivery to the respiring tissues. We therefore investigated O₂ binding properties of whole blood, stripped hemoglobin (Hb), two major isoHb components and the myoglobin (Mb) from M. albus. Whole blood was sampled using indwelling catheters for blood gas analysis and determination of O₂ equilibrium curves. Hb was purified to assess the effects of endogenous allosteric effectors, and Mb was isolated from heart and skeletal muscle to determine its O₂ binding properties. The blood of M. albus has a high O₂ carrying capacity [hematocrit (Hct) of 42.4±4.5%] and binds O₂ with an unusually high affinity (P₅₀=2.8±0.4mmHg at 27°C and pH7.7), correlating with insensitivity of the Hb to the anionic allosteric effectors that normally decrease Hb-O₂ affinity. In addition, Mb is present at high concentrations in both heart and muscle (5.16±0.99 and 1.08±0.19mg ∙ g wet tissue⁻¹, respectively). We suggest that the high Hct and high blood O₂ affinity serve to overcome the low diffusion capacity in the relatively inefficient respiratory surfaces, while high Hct and Mb concentration aid in increasing the O₂ flux from the blood to the muscles.
AB - The Asian swamp eel (Monopterus albus, Zuiew 1793) is a facultative air-breathing fish with reduced gills. Previous studies have shown that gas exchange seems to occur across the epithelium of the buccopharyngeal cavity, the esophagus and the integument, resulting in substantial diffusion limitations that must be compensated by adaptations in others steps of the O₂ transport system to secure adequate O₂ delivery to the respiring tissues. We therefore investigated O₂ binding properties of whole blood, stripped hemoglobin (Hb), two major isoHb components and the myoglobin (Mb) from M. albus. Whole blood was sampled using indwelling catheters for blood gas analysis and determination of O₂ equilibrium curves. Hb was purified to assess the effects of endogenous allosteric effectors, and Mb was isolated from heart and skeletal muscle to determine its O₂ binding properties. The blood of M. albus has a high O₂ carrying capacity [hematocrit (Hct) of 42.4±4.5%] and binds O₂ with an unusually high affinity (P₅₀=2.8±0.4mmHg at 27°C and pH7.7), correlating with insensitivity of the Hb to the anionic allosteric effectors that normally decrease Hb-O₂ affinity. In addition, Mb is present at high concentrations in both heart and muscle (5.16±0.99 and 1.08±0.19mg ∙ g wet tissue⁻¹, respectively). We suggest that the high Hct and high blood O₂ affinity serve to overcome the low diffusion capacity in the relatively inefficient respiratory surfaces, while high Hct and Mb concentration aid in increasing the O₂ flux from the blood to the muscles.
KW - Algorithms
KW - Allosteric Regulation
KW - Animals
KW - Aquaculture
KW - Biological Transport
KW - Fish Proteins
KW - Hematocrit
KW - Hemoglobins
KW - Hydrogen-Ion Concentration
KW - Kinetics
KW - Models, Biological
KW - Muscle, Skeletal
KW - Myocardium
KW - Myoglobin
KW - Oxygen
KW - Oxygen Consumption
KW - Protein Isoforms
KW - Respiratory Mucosa
KW - Smegmamorpha
KW - Vietnam
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
U2 - 10.1016/j.cbpa.2014.08.001
DO - 10.1016/j.cbpa.2014.08.001
M3 - Journal article
C2 - 25139401
VL - 178
SP - 102
EP - 108
JO - Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
JF - Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
SN - 1095-6433
ER -