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Modulation of perfusion and oxygenation by red blood cell oxygen affinity during acute anemia.
- Source :
-
American journal of respiratory cell and molecular biology [Am J Respir Cell Mol Biol] 2008 Mar; Vol. 38 (3), pp. 354-61. Date of Electronic Publication: 2007 Sep 20. - Publication Year :
- 2008
-
Abstract
- Responses to exchange transfusion using red blood cells (RBCs) with modified hemoglobin (Hb) oxygen (O(2)) affinity were studied in the hamster window chamber model during acute anemia to determine its role on microvascular perfusion and tissue oxygenation. Allosteric effectors were introduced in the RBCs by electroporation. Inositol hexaphosphate (IHP) and 5-hydroxymethyl-2-furfural (5HMF) were used to decrease and increase Hb-O(2) affinity. In vitro P50s (partial pressure of O(2) at 50% Hb saturation) were modified to 10, 25, 45, and 50 mm Hg (normal P50 is 32 mm Hg). Allosteric effectors also decreased the Hill coefficient. Anemic condition was induced by isovolemic hemodilution exchanges using 6% dextran 70 kD to 18% hematocrit (Hct). Modified RBCs (at 18% Hct in 5% albumin solution) were infused by exchange transfusion of 35% of blood volume. Systemic parameters, microvascular perfusion, capillary perfusion (functional capillary density, FCD), and microvascular Po(2) levels were measured. RBcs with P50 of 45 mm Hg increased tissue Po(2) and decreased O(2) delivery (Do(2)) and extraction (Vo(2)) and RBCs with P50 of 60 mmHg reduced FCD, microvascular flow, tissue Po(2), Do(2) and Vo(2). Erythrocytes with increased Hb-O(2) affinity maintained hemodynamic conditions, Do(2) and decreased tissue Po(2). This study shows that in an anemic condition, maximal tissue Po(2) does not correspond to maximal Do(2) and Vo(2).
- Subjects :
- Acute Disease
Anemia blood
Anemia metabolism
Anemia physiopathology
Animals
Blood Flow Velocity
Blood Pressure
Cricetinae
Data Interpretation, Statistical
Dextrans administration & dosage
Dextrans chemistry
Erythrocytes drug effects
Heart Rate
Hematocrit
Hemodilution methods
Hemoglobins metabolism
Hemorheology
Male
Mesocricetus
Molecular Weight
Osmotic Pressure
Partial Pressure
Perfusion
Plasma Substitutes administration & dosage
Plasma Substitutes chemistry
Random Allocation
Viscosity
Anemia therapy
Erythrocyte Transfusion
Erythrocytes metabolism
Microcirculation physiology
Oxygen blood
Subjects
Details
- Language :
- English
- ISSN :
- 1535-4989
- Volume :
- 38
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- American journal of respiratory cell and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 17884988
- Full Text :
- https://doi.org/10.1165/rcmb.2007-0292OC