Effects of isotonic swelling on the intracellular Bohr factor and the oxygen affinity of trout and carp blood

1996 ◽  
Vol 15 (5) ◽  
pp. 371-375 ◽  
Author(s):  
Karin Holk
Keyword(s):  
Oxygen Affinity ◽  
Bohr Factor

scholarly journals The Bohr/Haldane effect: a model-based uncovering of the full extent of its impact on O2 delivery to and CO2 removal from tissues

2018 ◽  
Vol 125 (3) ◽  
pp. 916-922 ◽  
Author(s):  
Hans Malte ◽  
Gunnar Lykkeboe
Keyword(s):  
Oxygen Affinity ◽  
Model System ◽  
Bohr Effect ◽  
Co2 Removal ◽  
Acid Base ◽  
Oxygen Equilibrium ◽  
Hemoglobin Oxygen Affinity ◽  
Bohr Factor ◽  
O2 Delivery ◽  
Oxygen Equilibrium Curve

For a century, the influence of the Bohr effect on the utilization of blood-borne oxygen has been deemed secondary to its influence on the uptake of carbon dioxide by the blood. Here, we show that the opposite is the case. Using a simple two-ligand, two-state formulation, we modeled the simultaneous oxygen and proton binding to hemoglobin, as well as the resulting acid-base changes of the surrounding solution. Blocking of the Bohr effect in this model system results in a dramatic increase in the oxygen affinity, as expressed by the oxygen partial pressure at half saturation, the P50. It also becomes clear that the P50 and the Bohr factor (a measure of the size of the Bohr effect) are not independent but directly related. Thus, everything else being equal, varying the number of Bohr groups from 0 to 8 per tetramer results in an increase in the Bohr factor from 0 to −0.9 and an increase in P50 from 6 to 46 mmHg at a constant Pco2 of 40 mmHg. Therefore, changes in hemoglobin structure that lead to changes in the Bohr factor will inevitably also change hemoglobin oxygen affinity. NEW & NOTEWORTHY Using a mathematical model, we show that the Bohr effect has a more profound effect on gas exchange than is evident when comparing oxygen equilibrium curves measured in the laboratory at different constant values of Pco2 or pH. Protons preloaded on the Bohr groups, as well as the protons taken up during oxygen unloading, dramatically decrease oxygen affinity of the physiological oxygen equilibrium curve. Therefore, the Bohr effect is instrumental in setting the oxygen affinity.

Oxygen dissociation curve for chorioallantoic capillary blood of chicken embryo

1976 ◽  
Vol 40 (3) ◽  
pp. 393-398 ◽  
Author(s):  
H. Tazawa ◽  
T. Ono ◽  
M. Mochizuki
Keyword(s):  
Oxygen Affinity ◽  
Capillary Blood ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
Oxygen Capacity ◽  
Bohr Factor ◽  
Hill’S Equations ◽  
Dissociation Curves ◽  
Clear Relation

Oxygen dissociation curves for blood in the chorioallantoic capillary of chicken embryos were determined using a microphotometric apparatus made for measuring the reaction velocity of a red blood cell with oxygen and carbon monoxide. The modified Hill's equations expressing the dissociation curve during development were calculated by two methods. P50's at pH of 7.4 were found to be 60.0, 54.4, 46.2, 33.1, and 28.6 mmHg for 10, 12, 14, 16 and 18 days of incubation, respectively. Although the Bohr factor did not show a clear relation to age, the oxygen affinity and the oxygen capacity tended to increase with the lapse of days, and the power of heme-to-heme interaction, to decrease with age. The findings imply that there is a respiratory adaptation of embryos during development.

Influence of temperature on hemoglobin-ligand interaction in whole blood

1977 ◽  
Vol 43 (3) ◽  
pp. 545-550 ◽  
Author(s):  
M. P. Hlastala ◽  
R. D. Woodson ◽  
B. Wranne
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Affinity ◽  
Temperature Dependent ◽  
Ligand Interaction ◽  
Influence Of Temperature ◽  
Dependent Change ◽  
Lower Oxygen ◽  
Hemoglobin Oxygen Affinity ◽  
Influence Of Temperature On ◽  
Bohr Factor

Temperature-dependent change in hemoglobin-oxygen affinity was measured as a function of hemoglobin-oxygen saturation. In addition, the CO2 Bohr factor and fixed acid Bohr factor were measured as a function of saturation of temperatures of 23, 30, 37, and 44 degrees C. Measurements were made on normal blood and blood with reduced 2,3-diphosphoglycerate (DPG). The influence of temperature is greatest at low saturation and is enhanced slightly by DPG depletion. The CO2 Bohr factor is increased at high temperatures; this is primarily due to increased carbamino formation with rising temperature, especially at lower oxygen saturation. The effect of DPG on oxygen affinity is reduced at a high temperature and elevated at low temperature. These diverse effects of temperature on hemoglobin-ligand interaction require consideration in assessing oxygen delivery when temperature is increased or decreased.

Oxygen affinity and Bohr coefficients of dog blood

1982 ◽  
Vol 53 (1) ◽  
pp. 87-95 ◽  
Author(s):  
R. B. Reeves ◽  
J. S. Park ◽  
G. N. Lapennas ◽  
A. J. Olszowka
Keyword(s):  
Blood Cells ◽  
Base Excess ◽  
Oxygen Affinity ◽  
Blood Film ◽  
Standard Curve ◽  
Co2 Levels ◽  
Dog Blood ◽  
Bohr Factor ◽  
Ph Range ◽  
Fixed Acid

Complete dynamic oxygen equilibrium curves (O2EC) on dog whole blood were measured at 25 and 39 degrees C using a spectrophotometric micro blood film technique. O2EC were run at three CO2 levels (2, 4, and 8%) for each of three base excess levels (-10, 0, +10 meq/l). The standard curve (ph 7.4) was determined for saturations 013;0.98. At 39 degrees C the standard curve O2 pressure at half-saturation (P50) was 31.5 Torr; fixed-acid Bohr factor, -0.488; CO2 Bohr factor, -0.498; delta log P50/delta log PCO2, -0.0045. CO2 Bohr slope was linear over the pH range of 7–8. Bohr factors were not significantly saturation dependent. At 25 degrees C P50 was 15.4 Torr and CO2 Bohr factor, -0.647. The temperature coefficient (delta log P50/delta T) equaled 0.022. Dog O2EC were shown with curve-fitting techniques to be isomorphic with human blood O2EC. The absence of significant oxylabile carbamate formation in dog red blood cells (RBC) was attributed to high 2,3-diphosphoglycerate (DPG) concentrations, 6.23 mM/l RBC, equal to a DPG/Hb4 ratio of 1.12. A simple two-constant equation S = [(37,900)/(P3 + 205P) + 1]-1, where S is saturation and P is oxygen tension, was found to fit the dog 39 degrees C standard curve.

Determination of interdependent ligand effects on human red cell oxygen affinity

1982 ◽  
Vol 42 (4) ◽  
pp. 339-345
Author(s):  
W. G. Zijlstra ◽  
B. Oeseburg ◽  
G. Kwant ◽  
A. Zwart
Keyword(s):  
Oxygen Affinity ◽  
Red Cell ◽  
Ligand Effects

EFFECT OF BW12C ON OXYGEN AFFINITY OF HAEMOGLOBIN IN SICKLE-CELL DISEASE

The Lancet ◽  
1986 ◽  
Vol 327 (8485) ◽  
pp. 831-834 ◽  
Author(s):  
A.J. Keidan ◽  
R.D. White ◽  
E.R. Huehns ◽  
I.M. Franklin ◽  
M. Joy ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Oxygen Affinity ◽  
Cell Disease

scholarly journals Molecular Pathways Involved in the Development of Congenital Erythrocytosis

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1150
Author(s):  
Jana Tomc ◽  
Nataša Debeljak
Keyword(s):  
Signal Transduction ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Oxygen Affinity ◽  
Molecular Pathways ◽  
Disease Development ◽  
Post Translational Modifications ◽  
Hemoglobin Oxygen Affinity ◽  
Insight Into ◽  
Idiopathic Erythrocytosis

Patients with idiopathic erythrocytosis are directed to targeted genetic testing including nine genes involved in oxygen sensing pathway in kidneys, erythropoietin signal transduction in pre-erythrocytes and hemoglobin-oxygen affinity regulation in mature erythrocytes. However, in more than 60% of cases the genetic cause remains undiagnosed, suggesting that other genes and mechanisms must be involved in the disease development. This review aims to explore additional molecular mechanisms in recognized erythrocytosis pathways and propose new pathways associated with this rare hematological disorder. For this purpose, a comprehensive review of the literature was performed and different in silico tools were used. We identified genes involved in several mechanisms and molecular pathways, including mRNA transcriptional regulation, post-translational modifications, membrane transport, regulation of signal transduction, glucose metabolism and iron homeostasis, which have the potential to influence the main erythrocytosis-associated pathways. We provide valuable theoretical information for deeper insight into possible mechanisms of disease development. This information can be also helpful to improve the current diagnostic solutions for patients with idiopathic erythrocytosis.

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