Improved oxygen release: an adaptation of mature red cells to hypoxia

cytosis secondary to arterial hypoxemia due either to congenital heart disease or to chronic obstruc-tive pulmonary disease was shown to have a de-creased affinity for oxygen; the average oxygen pressure required to produce 50 % saturation of hemoglobin with oxygen was 29.8 mm Hg (aver-age normal, 26.3 mm Hg). Such a displacement of the blood oxygen equilibrium curve promotes the release of oxygen from blood to the tissues. Studies were also performed upon blood from a man with complete erythrocyte aplasia who re-ceived all of his red cells by transfusion from presumably normal persons. With mild anemia (hematocrit, 28%), the affinity of his blood for oxygen was slightly diminished (an oxygen pres-sure of 27.0 mm Hg was required to produce 50%o saturation of hemoglobin with oxygen). With Dr. Miles J. Edwards is an Assistant Professor o