Oxygen affinity and Bohr coefficients of dog blood.
Complete dynamic oxygen equilibrium curves (O2EC) on dog whole blood were measured at 25 and 39 degrees C using a spectrophotometric micro blood film technique. O2EC were run at three CO2 levels (2, 4, and 8%) for each of three base excess levels (-10, 0, +10 meq/l). The standard curve (ph 7.4) was determined for saturations 0-0.98. At 39 degrees C the standard curve O2 pressure at half-saturation (P50) was 31.5 Torr; fixed-acid Bohr factor, -0.488; CO2 Bohr factor, -0.498; delta log P50/delta log PCO2, -0.0045. CO2 Bohr slope was linear over the pH range of 7-8. Bohr factors were not significantly saturation dependent. At 25 degrees C P50 was 15.4 Torr and CO2 Bohr factor, -0.647. The temperature coefficient (delta log P50/delta T) equaled 0.022. Dog O2EC were shown with curve-fitting techniques to be isomorphic with human blood O2EC. The absence of significant oxylabile carbamate formation in dog red blood cells (RBC) was attributed to high 2,3-diphosphoglycerate (DPG) concentrations, 6.23 mM/l RBC, equal to a DPG/Hb4 ratio of 1.12. A simple two-constant equation S = [(37,900)/(P3 + 205P) + 1]-1, where S is saturation and P is oxygen tension, was found to fit the dog 39 degrees C standard curve.
D019794:2,3-Diphosphoglycerate; D000818:Animals; D004163:Diphosphoglyceric Acids / Q000097:blood; D004285:Dogs / Q000097:blood*; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008297:Male; D010100:Oxygen / Q000097:blood*; D010108:Oxyhemoglobins / Q000378:metabolism*; D013696:Temperature
D004163:Diphosphoglyceric Acids; D006454:Hemoglobins; D010108:Oxyhemoglobins; D019794:2,3-Diphosphoglycerate; D010100:Oxygen