Effect of iodoacetate and fluoride on the position of the haemoglobin oxygen dissociation curve of human whole blood.

Abstract

THE influence of various electrolytes on the position (haemoglobin–oxygen affinity) and on the slope (haem–haem interaction) of the oxygen dissociation curve (ODC) of pure haemoglobin solutions has been known for several years1–3. Recent investigations4–6 have revealed the unique role of organic phosphates, such as 2,3-di-phosphoglycerate (2,3-DPG), as determinants of the haemoglobin–oxygen affinity. Thus, with pure haemoglobin solutions, an increase in the concentration of 2,3-DPG in the medium decreases the affinity by competitive reaction with oxygen6, while a decreased concentration of 2,3-DPG is associated with an increased affinity for oxygen. The concentrations of 2,3-DPG used in these experiments are in the range which occurs in normal or abnormal physiological conditions in the intact erythrocyte. Because variations in concentrations of 2,3-DPG do not appear to influence the sigmoid shape of the ODC but only its position, these compounds presumably do not affect the haem–haem interaction6.