Hypoxia and comparative physiology in humans: Diversity in haemoglobin and oxygen dissociation curve shifting

2020 ◽  
pp. 41-43
Author(s):  
Michael J Joyner ◽  
Paolo B Dominelli
Keyword(s):  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Comparative Physiology ◽  
Oxygen Dissociation

Red-cell 2,3-diphosphoglycerate in patients with hyperthyroidism

1980 ◽  
Vol 93 (4) ◽  
pp. 424-429 ◽  
Author(s):  
J. L. Alvarez-Sala ◽  
M. A. Urbán ◽  
J. J. Sicilia ◽  
A. J. Diaz Fdez ◽  
F. Fdez Mendieta ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Control Group ◽  
Red Cell ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Right ◽  
Serum Thyroid Hormones ◽  
Hyperthyroid Patients ◽  
2,3 Dpg

Abstract. In 21 hyperthyroid female patients studied on 29 occasions, high levels of red-cell 2,3-diphosphoglycerate (2,3-DPG) have been found (5.75 ± 0.7 mm) which, compared to a euthyroid control group (4.88 ± 0.4 mm), could not be accounted for by differences in haematocrit, haemoglobin or phosphataemia. A significant correlation was found (P < 0.05) between serum thyroid hormones and the 2,3-DPG concentration in the hyperthyroid patients. Eight of these patients were reexamined after treatment and normalization of thyroid function, showed a regression to normal 2,3-DPG values (4.81 ± 0.6 mm) which could not be attributed to variations in haematocrit, haemoglobin or phosphataemia either. We therefore deduce that the shift to the right in the haemoglobin oxygen dissociation curve observed in patients of this type may be due to an increase in the red-cell 2,3-DPG content.

scholarly journals Hemoglobin Non-equilibrium Oxygen Dissociation Curve

2020 ◽  
Author(s):  
Rosella Scrima ◽  
Sabino Fugetto ◽  
Nazzareno Capitanio ◽  
Domenico L. Gatti
Keyword(s):  
Partial Pressure ◽  
Correct Diagnosis ◽  
Oxygen Affinity ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
High Affinity ◽  
Oxygen Dissociation ◽  
Sequential Binding ◽  
Non Equilibrium

AbstractAbnormal hemoglobins can have major consequences for tissue delivery of oxygen. Correct diagnosis of hemoglobinopathies with altered oxygen affinity requires a determination of hemoglobin oxygen dissociation curve (ODC), which relates the hemoglobin oxygen saturation to the partial pressure of oxygen in the blood. Determination of the ODC of human hemoglobin is typically carried out under conditions in which hemoglobin is in equilibrium with O2 at each partial pressure. However, in the human body due to the fast transit of RBCs through tissues hemoglobin oxygen exchanges occur under non-equilibrium conditions. We describe the determination of non-equilibrium ODC, and show that under these conditions Hb cooperativity has two apparent components in the Adair, Perutz, and MWC models of Hb. The first component, which we call sequential cooperativity, accounts for ∼70% of Hb cooperativity, and emerges from the constraint of sequential binding that is shared by the three models. The second component, which we call conformational cooperativity, accounts for ∼30% of Hb cooperativity, and is due either to a conformational equilibrium between low affinity and high affinity tetramers (as in the MWC model), or to a conformational change from low to high affinity once two of the tetramer sites are occupied (Perutz model).

An electrolytic method for determining oxygen dissociation curves using small blood samples: the effect of temperature on trout and human blood

1976 ◽  
Vol 65 (1) ◽  
pp. 21-38
Author(s):  
G. M. Hughes ◽  
J. G. O'Neill ◽  
W.J. van Aardt
Keyword(s):  
Human Blood ◽  
Marked Effect ◽  
Effect Of Temperature ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
Fish Blood ◽  
Bohr Factor ◽  
Dissociation Curves ◽  
The Relationship

1. A detailed account is given of an electrolytic method for determining the oxygen dissociation curve of fish blood using a single sample of 50–100 mul for the whole curve. The accuracy and some of the problems arising from its uses are discussed. 2. Oxygen dissociation curves have been determined for trout blood and human blood at temperatures of 15 and 37 degrees C. The relationship between P50 and temperature is similar to that obtained using other methods. Absolute values of P50 are generally lower than those obtained by other methods, especially in the case of fish blood. 3. The effect of PCO2 and pH on the oxygen dissociation curve of trout blood is tested and it is shown that PCO2 has a more marked effect than pH when the other factor is maintained at a constant level. The Bohr factor (delta log P50/delta pH) appears to be approximately the same and independent of the PCO2. 4.The P50 of ray blood determined from fish during and after an operation showed an increased Bohr factor.

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