Oxygen-hemoglobin equilibrium of normal and glutathione-deficient sheep

The affinity of hemoglobin for oxygen did not differ significantly between normal and glutathione-deficient sheep. Although phlebotomy in sheep of both types did not significantly alter the partial pressure values at which hemoglobin is 50% saturated with oxygen, it did increase significantly the erythrocyte glutathione and 2,3-diphosphoglycerate (GSH) and (DPG) concentrations. Because DPG does not bind to sheep hemoglobin, its increase in hypoxic sheep must mean DPG is metabolically controlled in the absence of physiologic effect.