Effect of carbamination on the buffering power of purified human hemoglobin A solutions at two temperatures

Temperature independence of the alkaline Bohr effect in pig red cells and pig haemoglobin solutions

The influence of temperature on the oxygen affinity and the alkaline Bohr effect of pig red cells and pig hemoglobin solutions has been compared to that of human adult red cells and human adult hemoglobin. Pig red cells and pig Hb evidence a lower affinity for oxygen in various conditions of pH, temperature and salt concentration, in the presence as well as in the absence of organic phosphates. It has been observed that the alkaline Bohr effect of pig Hb was reduced by 20-25% compared to Hb A0 and independent of changes in temperature, contrary to human Hb A0. Titrations of pig Hb with C1- indicate a lower heterotropic effect of this anion at low concentration of the salt. It is concluded that this may be the origin of the temperature independence of the alkaline Bohr effect in pig Hb. Conversely, the temperature dependence of the alkaline Bohr effect of Hb A0 should be related to the oxygen-linked binding of C1- at the alpha 1-alpha 2 interface.

The apparent buffer value of human blood for CO2 as a function of temperature

The influence of temperature on the acid-base status of normal human deoxygenated whole blood was studied in open systems (variable total CO2 content). (1) When the temperature was raised from 26 degrees C to 42 degrees C, the apparent buffering value of deoxygenated whole blood for CO2 increased by 7% of its value at 26 degrees C; this increase was not statistically significant. (2) Comparing the present data with those obtained previously from oxygenated whole blood in the same temperature range (Castaing & Pocidalo, 1979) indicates that arterial and venous blood have slightly different buffering capacities for CO2 in the 26 to 42 degrees C temperature range. It also suggests that, at physiological SO2 levels (SO2 greater than or equal to 30%), the apparent buffering value of venous blood for CO2 would be increased by at least 10% of its value at 26 degrees C when the temperature is raised to 42 degrees C. (3) It is concluded that pH stability would be reduced upon CO2 uptake within tissues with a high metabolism and therefore a high temperature.