Ligand kinetics of hemoglobin S containing erythrocytes

Oxygen uptake of fully deoxygenated sickle (SS) erythrocytes is slower than that of normal (AA) erythrocytes, as demonstrated by the half-times of the overall oxygenation reactions: at 25 degrees in an isotonic phosphate buffer the normal red cells have a t1/2 = 82 +/- 4.7 msec, as compared to sickle red cells where t1/2 = 135 +/- 17.6 msec. The effects of temperature, extracellular osmolality, and the presence of an antisickling agent (n-butylurea) on the rate of red cell oxygenation strongly suggest that the differences in oxygenation rates encountered with sickle red cells is directly related to the intracellular polymerization of deoxyhemoglobin S.