Enhanced Oxygen Unloading by an Interdimerically Crosslinked Hemoglobin in an Isolated Perfused Rabbit Heart

Coronary perfusion has shown that an intramolecularly crosslinked hemoglobin (Hb) with a very low affinity for O2(Hb crosslinked covalently between the β chains with 2-nor-2-formylpyridoxal 5′-phosphate, HbXL) has several advantages over ordinary Hb. As predicted from in vitro oxygenation curves, mu...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 1984-05, Vol.81 (9), p.2941-2943
Main Authors: Benesch, Reinhold, Triner, Lubos, Benesch, Ruth E., Kwong, Suzanna, Verosky, Mariagnes
Format: Article
Language:English
Subjects:
Animals
Blood
Blood substitutes
Coronary Circulation
Cross-Linking Reagents
Extracorporeal Circulation
Heart
Heart rate
Hemoglobins
Humans
Lead
Organ Preservation
Oxygen
Oxygen - blood
Oxygen Consumption
Oxyhemoglobins - metabolism
Perfusion
Rabbits
Structure-Activity Relationship
Temperature
Tissue oxygenation
Ventricular pressure
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Summary:Coronary perfusion has shown that an intramolecularly crosslinked hemoglobin (Hb) with a very low affinity for O2(Hb crosslinked covalently between the β chains with 2-nor-2-formylpyridoxal 5′-phosphate, HbXL) has several advantages over ordinary Hb. As predicted from in vitro oxygenation curves, much more O2was unloaded to the heart at three different heart rates, at two perfusion rates, and when the perfusate was equilibrated with 25% as well as 95% O2. In all cases, the improved O2unloading occurred at higher tissue O2pressures than with normal Hb. The greater O2consumption with HbXL was accompanied by better mechanical performance because, after 90 min of perfusion, the HbXL-perfused hearts maintained two-thirds of their original contractility (dp / dt), while that of the Hb-perfused hearts had declined to one-fifth. A special advantage of HbXL is its ability to unload significant amounts of O2even at low temperature (10 degrees C), in contrast to whole blood. This should make it useful for supporting aerobic metabolism during low-temperature cardioplegia in cardiac surgery and for organ preservation.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.81.9.2941