Human whole-blood oxygen affinity: effect of temperature

1984 ◽  
Vol 57 (2) ◽  
pp. 429-434 ◽  
Author(s):  
A. Zwart ◽  
G. Kwant ◽  
B. Oeseburg ◽  
W. G. Zijlstra

phe effect of temperature changes on human whole-blood O2 affinity was measured in the blood of six healthy donors over almost the entire O2 saturation (SO2) range (1–99%). The results showed that temperature has no influence on the shape of the O2 dissociation curve, implying that the temperature coefficient (delta log PO2/delta T) is independent of SO2. Simultaneous measurements of the total (proton) Haldane factor (delta[HbH]/[delta HbO2]) at the five temperatures under study (22, 27, 32, 37, and 42 degrees C) revealed that this factor depends on temperature. The liberation of protons from hemoglobin appeared to be linear with respect to changes in SO2. We therefore conclude that the (proton) Bohr factor (H+ factor) is dependent on temperature over the entire SO2 range in the same way as previously described for SO2 = 50%. The exothermic oxygenation reaction in whole blood was accompanied by a heat evolution (delta HO2) of 42.7 kJ/mol (monomeric) hemoglobin.

1984 ◽  
Vol 57 (1) ◽  
pp. 14-20 ◽  
Author(s):  
A. Zwart ◽  
G. Kwant ◽  
B. Oeseburg ◽  
W. G. Zijlstra

Oxygen dissociation curves (ODC) were recorded in the presence of carboxyhemoglobin fractions (FHbCO) up to 60%. The gradual shift to the left of the ODC at increasing amounts of HbCO was reflected in a gradual fall in the half-saturation pressure of the remaining Hb and was accompanied by a gradual change in the shape of the ODC to a hyperbolic one. The H+ factor (delta log PO2/delta pH) was determined over the entire oxygen saturation (SO2) range at three different FHbCO levels (14, 30, and 52%). At FHbCO = 14 and 30% and for the SO2 range 20–90%, the H+ factor vs. SO2 curve was not significantly different from that in the absence of HbCO. At FHbCO = 52%, however, the value found for the H+ factor (-0.55) was appreciably more negative than in the case of blood containing less than 1% HbCO (-0.44), and there was no dependence on SO2. Comparison of measured and calculated ODCs at varying HbCO fractions showed, for FHbCO less than or equal to 50%, that measured and calculated ODCs coincide over the greater part of the SO2 range. For FHbCO greater than 50%, the measured ODC was situated to the left of the calculated one over the entire SO2 range. We conclude that the heme-heme interaction for CO is appreciably larger than for O2 only for FHbCO greater than 50%, whereas for FHbCO less than 50% there is virtually no difference.


Blood ◽  
1972 ◽  
Vol 39 (3) ◽  
pp. 398-406 ◽  
Author(s):  
Frank G. de Furia ◽  
Denis R. Miller

Abstract Oxygen affinity studies in a splenectomized patient with sporadically occurring Hb Köln disease revealed high whole blood oxygen affinity (P50 O2 17.6 mm Hg) with increased 2, 3-diphosphoglycerate (DPG), low ATP, and normal RBC ΔpH. Isolated electrophoretically slow migrating Hb Köln had a high oxygen affinity, decreased Hill’s number, and normal DPG reactivity. Functional evidence for hybrid tetramers with normal mobility is presented. Partial deoxygenation may play a role in the denaturation of the Hb Köln molecule and thus account for a higher oxygen affinity (low P50 O2), measured by the mixing technique, than the actual values for P50 that exist in vivo. Increased oxygen affinity and decreased P50 O2 would result in increased erythropoiesis and account for a well-compensated hemolytic process in this patient with a normal red cell mass and normal values of hemoglobin.


1978 ◽  
Vol 19 (4) ◽  
pp. 688-692 ◽  
Author(s):  
S. Berglund ◽  
T. Almén ◽  
B. W. Johansson

1983 ◽  
Vol 103 (1) ◽  
pp. 95-108
Author(s):  
R. M. Wells ◽  
R. E. Weber

A typical whole blood O2-equilibrium curve from Squalus acanthias had a P50 of 13.2 mmHg and was slightly sigmoidal, having an n value of 1.6 at 15 degrees C, PCO2 = 2.2 mmHg (pH = 7.85). A small Bohr effect was present (phi = −0.28) together with a weak Haldane effect and no Root shift. The predominant trinucleotide, determined by thin layer chromatography, was ATP (0.44 +/− 0.13 S.D. mmol 1(−1) blood) with smaller amounts of GTP present (0.07 +/− 0.02) S.D. mmol 1(−1). Total nucleotide concentrations, determined enzymatically, were low by comparison with teleosts. Incubation of erythrocytes with or without oxygen, or in the presence of a metabolite-enriched ‘cocktail’ showed limited potential for phosphate cofactor regulation of blood oxygen affinity.


1993 ◽  
Vol 175 (1) ◽  
pp. 15-32 ◽  
Author(s):  
G. C. Grigg ◽  
R. M. G. Wells ◽  
L. A. Beard

The P50 of whole blood [30°C, PCO2=2.08 kPa (15.6 mmHg)] decreases during embryonic development from approximately 6.7 kPa (50 mmHg) at 15 days to about half this value at hatching (86 days), paralleling a decrease in ATP from 100 to 5–10 micromole g-1 Hb. There is also a progressive changeover from embryonic to adult haemoglobin (HbA). A pulse of 2,3- diphosphoglycerate (2,3-DPG) (18 micromole g-1 Hb) occurs late in embryonic life. It has no effect on whole-blood oxygen-affinity and falls rapidly at hatching to values typical of post-hatchling crocodilians in general (<1.0 micromole g-1 Hb). ATP has a marked effect on the oxygen affinity of embryonic haemoglobin (HbE) but not on HbA. 2,3-DPG has only very small effects on the oxygen affinities of HbE and HbA. CO2 has a small effect on the oxygen affinity of HbE but a marked effect on that of HbA. Values of PO2 measured in the chorio-allantoic artery [2.9 kPa (22 mmHg)] and vein [5.9 kPa (52 mmHg)] imply an increase in saturation from approximately 30 % to more than 80 %. Neither whole-blood oxygen-affinity nor ATP level was altered in response to an experimental 7-day exposure to low ambient oxygen levels [10.7 kPa (80 mmHg)]. The results do not lend themselves easily to the pan-selectionist paradigm in which all physiological traits are viewed as being adaptive.


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