Partition of Carbon Monoxide and Oxygen Between Air and Whole Blood of Rats, Dogs and Men as Affected by Plasma pH

The competition between CO and O2 for intracellular hemoglobin of rat, dog and human blood at 37°C is influenced by the CO2 tension in aerotonometers. The peak M values occur at the normal range in plasma pH, being close to 225 for dogs and men and 192 for rats. These values are 30% lower at ph = 7.1 and up to 40% lower at ph = 7.6. At the higher ph the M values of the three hemoglobins are similar. Evidence is presented showing that CO is slowly oxidized by intracellular hemoglobin at a rate varying directly with the percentage of COHb. Submitted on June 15, 1956