Oxygen transport by pyridoxylated polyhemoglobin solution.
Pyrodoxylated Polyhemoglobin (PolyHb-PPa) with physiological oxygen affinity (P50 27 mm Hg) was used in vitro and in vivo. The oxygen binding coefficient was 1.1 ml O2/dl/g Hb, the oxygen capacity of 8.5% PolyHb-PPa solution 9.3 ml O2/dl, Hill coefficient 1.7, Met-Hb content below 2%. Exchange transfusion of whole blood with PolyHb-PPa results in a significant, linear increase in total oxygen capacity, in contrast to exchange transfusion with asanguineous solutions. In vitro analysis of oxygen equilibrium curves of mixtures of whole blood with PolyHb-PPa, however, shows a nonlinear release of the additional blood oxygen capacity. Significant amounts of PolyHb-PPa-bound oxygen are made available only when hemodilution exceeds 25%; only at 75% hemodilution does oxygen delivery by PolyHb-PPa account for 50% of the unloaded oxygen. In vivo results after therapy for hemorrhagic shock in minipigs clearly shows the efficacy of oxygen transport by PolyHb-PPa. At 70% hemodilution, PolyHb-PPa bound oxygen was twice that of erythrocytic oxygen. Availability of this additional oxygen capacity was demonstrated by an oxygen extraction ratio of 0.40%. The utility of PolyHb-PPa solution with "normal" P50 in the therapy of moderate anemia, however, remains to be proved.
Lenz
G
G
Dept. of Anesthesiology, University of Tübingen, Federal Republic of Germany.
Bissinger
U
U
Benzing
H
H
D000818:Animals; D001693:Biological Transport, Active; D001802:Blood Substitutes / Q000378:metabolism* / Q000627:therapeutic use; D004338:Drug Combinations; D005466:Fluorocarbons / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism / Q000627:therapeutic use; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives; D066298:In Vitro Techniques; D007700:Kinetics; D010100:Oxygen / Q000097:blood*; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use; D012771:Shock, Hemorrhagic / Q000097:blood / Q000188:drug therapy; D013552:Swine; D013556:Swine, Miniature
D001802:Blood Substitutes; D004338:Drug Combinations; D005466:Fluorocarbons; D006454:Hemoglobins; D006895:Hydroxyethyl Starch Derivatives; C030939:polyhemoglobin-pyridoxal-5-phosphate; D011732:Pyridoxal Phosphate; C017323:glucose, glycerol, hydroxyethyl starch, perfluorodecalin, perfluorotripropylamine, pluronic F-68, salts, yolk phospholipids drug combination; D010100:Oxygen