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This Article Full Text Full Text (PDF) All Versions of this Article: 295/3/H1090    most recent 00303.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Irwin, D. C. Articles by Gotshall, R. W. PubMed PubMed Citation Articles by Irwin, D. C. Articles by Gotshall, R. W.

Polymerized bovine hemoglobin decreases oxygen delivery during normoxia and acute hypoxia in the rat

¹Cardiovascular Pulmonary Research Group, School of Medicine; ²Department of Anesthesiology, University of Colorado Health Science Center, Aurora, Colorado; ³Department of Health and Exercise Science; and ⁴Department of Biomedical Sciences School of Veterinary Medicine, James L. Voss Veterinary Teaching Hospital, Colorado State University, Fort Collins, Colorado

Submitted 20 March 2008 ; accepted in final form 17 June 2008

Hemoglobin-based oxygen carriers (HBOC) have been primarily studied for blood loss treatment. More recently infusions of HBOC in euvolemic subjects have been proposed for a wide variety of potential therapies in which increased tissue oxygenation would be beneficial. However, compared with the exchange transfusion models to study blood loss, less is known about HBOC oxygen delivery and vasoacitvity when it is infused in euvolemic subjects. We hypothesized that HBOC [polymerized bovine hemoglobin (PBvHb)] infusion creating hypervolemia would increase oxygen delivery to tissues during acute global hypoxia. Vascular oxygen content and hemodynamics were determined after euvolemic rats were infused with 3 ml of either lactated Ringer or PBvHb solution (13 g/dl, 1.3 g/kg) during acute hypoxia (FIO₂ = 10%, 4 h) or normoxia (FIO₂ = 21%) exposure. Our data demonstrated that compared with Ringer-infused animals, in hypoxia and normoxia, PBvHb treatment improved oxygen content but raised mean arterial pressure, lowered stroke volume, heart rate, and cardiac index, which resulted in a net reduction in blood flow and oxygen delivery to the tissues. The PBvHb vasoactive effect was similar in magnitude and direction as to the Ringer-infused animals treated with a nitric oxide synthase inhibitor nitro-L-arginine, suggesting the PBvHb effect is mediated via nitric oxide scavenging. We conclude that infusion of PBvHb is not likely to be useful in treating global hypoxia under these conditions.

hemoglobin-based oxygen carriers; Nitric oxide; Cardiac output