Kinetics of oxygenation and deoxygenation of erythrocytes containing hemoglobin S

The rates of oxygenation and deoxygenation of erythrocytes from normal individuals and patients with sickle cell anemia have been measured at physiologic pH and temperature. The oxygenation reaction velocity constant for the cells from the patients was half that for cells from normal controls (44.5±14.8 mM^-1 sec^-1 as compared to 89.4±23.1 mM^-1 sec^-1). However the deoxygenation velocity constant for cells from patients was almost twice that for cells from the normal controls (20.8±2.4 sec^-1 as compared to 11.0±1.6 sec^-1). These differences in kinetic constants apparently result from alterations in the internal cellular environment rather than from the differences in structure of hemoglobin A and S. The factors responsible for the observed changes are not apparent. The decreased rate of oxygen uptake by hemoglobin S cells may possibly produce an end-capillary oxygen difference between blood and alveolar gas in areas of the lung with low ratios of diffusing capacity to blood flow.