Effect of carbon monoxide on equilibrium between oxygen and hemoglobin.
Oxygen dissociation curves of partially CO-saturated human whole blood drawn freshly or preserved more than 3 wk were studied. With increasing CO-hemoglobin concentrations, oxygen affinity of the blood increased and the Hill coefficient, n, fell and gradually approached unity. The changes induced by CO-hemoglobin showed practically no difference in the presence or absence of 2,3-diphosphoglycerate. The Bohr coefficient, deltalog P50/deltapH, was determined as a function of oxygen saturation for various concentrations of CO-hemoglobin. The coefficient remained essentially unchanged in the presence of CO-hemoglobin. In the presence of less than 50% CO-hemoglobin, a good agreement was observed between the observed oxygen dissociation curves and the curves calculated according to Roughton and Darling (Am. J. Physiol. 141: 17-31, 1944). Based on these results, physiological implications of carboxyhemoglobinemia are discussed quantitatively in comparison with methemoglobinemia.
D002263:Carboxyhemoglobin / Q000494:pharmacology*; D006418:Heme / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism* / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D010100:Oxygen / Q000097:blood*
D006454:Hemoglobins; D006418:Heme; D002263:Carboxyhemoglobin; D010100:Oxygen