THE EQUILIBRIUM BETWEEN HEMOGLOBIN AND OXYGEN IN WHOLE AND HEMOLYZED BLOOD OF THE TAUTOG, WITH A THEORY OF THE HALDANE EFFECT

¹ From the College of the City of New York; Swarthmore College; and the Marine Biological Laboratory, Woods Hole

1. A detailed study has been made of the effect of CO₂ on the equilibrium between hemoglobin and oxygen in whole and hemolyzed blood of the tautog.

2. The study of the O₂-dissociation curves of whole blood has shown that the addition of CO₂ up to 100 mm. pressure changes the shape of the curves from sigmoid to rectangular hyperbolae with approximately 50 per cent of the hemoglobin inactivated. The intermediate stages in the transformation produce complex dissociation curves which can be described by assuming that fish hemoglobin is made up of different O₂-combining components acting independently of each other and combining with different amounts of oxygen at a time.

3. Hemolysis renders the hemoglobin less sensitive to CO₂ as evidenced by the fact that the O₂-dissociation curves move far to the left of those for whole blood; that the O₂-combining components which combine with more than one molecule of O₂ at a time show greater stability than they do in whole blood as the CO₂ tension is raised; and that there is no hemoglobin inactivation up to at least 100 mm. CO₂. There is still a prominent Bohr effect, however, and the O₂-combining components still gradually change their behavior as the CO₂ tension is raised.

4. Based primarily upon the characteristics of the equilibrium between hemoglobin and oxygen, a theory is offered to explain certain peculiarities of the effect of oxygenation on the CO₂-combining power of the blood (Haldane effect). The theory offered provides a common explanation for the anomalies in the effect of CO₂ on oxygenation of the hemoglobin and in the reciprocal effect of oxygenation on the CO₂-combining power of the blood.