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In vivo polymerization of sickle-cell hemoglobin: a theoretical study
1Department of Mechanical Engineering, University of Rochester, New York.
Blood Cells
|January 1, 1994
Summary
Equilibrium studies overestimate sickle hemoglobin (HbS) polymer concentration and underestimate oxygen content in sickle red blood cells during oxygen unloading. Physiological conditions show longer polymerization delays than previously thought.
Area of Science:
- Hematology
- Biophysics
Background:
- Sickle red blood cell gelation and HbS polymerization are studied under equilibrium and fully deoxygenated conditions.
- The physiological relevance of these equilibrium-based studies in vivo remains unclear.
Purpose of the Study:
- To compare theoretical equilibrium predictions with values under physiological oxygen unloading conditions.
- To simulate HbS polymerization kinetics in sickle erythrocytes during dynamic oxygen unloading.
Main Methods:
- Utilized a validated theoretical model to analyze HbS polymer concentration and cellular oxygen content.
- Simulated polymerization in deoxygenated sickle erythrocytes and compared with published data.
Main Results:
- Equilibrium predictions significantly overestimate intracellular HbS polymer concentrations during oxygen unloading.
- Equilibrium predictions underestimate cellular oxygen content under physiological conditions.
- Physiological polymerization delay times are substantially longer than those in fully deoxygenated solutions.
Conclusions:
- In vivo HbS polymerization is significantly influenced by the rate of oxygen desaturation.
- Equilibrium estimates of HbS polymer content and kinetic data from deoxygenated solutions may be misleading for in vivo conditions.
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