The Effect of Temperature on the Acid-base- Protein Equilibrium and Its Influence on the Co2 Absorption Curve of Whole Blood, True and Separated Serum

The influence of change of temperature on the carbonic acidbase-protein equilibrium in blood or serum involves three factors: (1) Change in solubility of CO2 in serum or blood. (2) Change in the equilibrium constants of the buffer systems in the blood. (3) Change in the equilibrium constant for the dissociation of water. The fact that the solubility of CO2 changes with temperature has naturally been fully appreciated. On the other hand, the physiological significance of the change in the dissociation constant of water is more or less obscure but has been discussed in a recent paper by Austin and Cullen (1925). These topics will not be considered here. The relations of temperature to the equilibrium constants of the buffer systems of the blood were discussed by Stadie and Martin (1924) whose work was confined to whole blood. Further work from this laboratory by Cullen, Keeler, and Robinson (1925) together with that presented in this paper have enabled us to extend the equilibrium relations as affected by temperature so as to include true serum and separated serum as well as whole blood. In addition the relations developed lead to a theoretical expression for one of the factors in the C correction of Cullen used to convert [pH] of serum at 200C. to pH at 38° which shows the limitations of the C correction as a constant.