The 24‐Hour Posttransfusion Survival and Lifespan of Autologous Baboon Red Cells Treated with Inositol Hexaphosphate‐Polyethylene Glycol or Inositol Hexaphosphate‐Adenosine Triphosphate‐Polyethylene Glycol to Decrease Oxygen Affinity1

Abstract
Baboon red cells were treated to reduce oxygen affinity by an osmotic‐pulse procedure using dimethyl‐sulfoxide. Inositol hexaphosphate (IHP) alone or IHP and adenosine triphosphate (ATP) were incorporated into the red cells in the presence of polyethylene glycol (PEG). The procedure produced variable increases in the red cell P50value, i.e., the partial pressure of oxygen at which 50% of the hemoglobin was saturated. The effect of treatment of autologous baboon red cells on the 24‐hour posttransfusion survival value and lifespan T50value was measured using a double‐label procedure. The data demonstrate that the increase in the P50value of treated red cells was negatively correlated with the 24‐hour posttransfusion survival value; the higher the P50value, the poorer the 24‐hour posttransfusion survival value. The 24‐hour posttransfusion survival value for nontreated baboon red cells was 90% and the T50value was 14 days. The IHP‐ATP‐PEG‐treated red cells had significantly higher red cell ATP levels than did IHP‐PEG‐treated red cells. The 24‐hour posttransfusion survival value was 68% for the IHP‐ATP‐PEG treated red cells and 52% for the IHP‐PEG‐treated red cells when the increase in P50ranged from 10 to 20 mm Hg; the lifespan T50value for both the IHP‐ATP‐PEG‐treated red cells and the IHP‐PEG‐treated red cells was 15 days. Osmotic pulse treatment produced significant red cell injury manifested by the 24‐hour posttransfusion survival value. However, modification of the RBC with IHP‐PEG or IHP‐ATP‐PEG to decrease hemoglobin affinity for oxygen did not affect their lifespan.