Effect of carbon monoxide on equilibrium between oxygen and hemoglobin

1976 ◽  
Vol 230 (2) ◽  
pp. 471-475 ◽  
Author(s):  
Y Okada ◽  
I Tyuma ◽  
Y Ueda ◽  
T Sugimoto
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Saturation ◽  
Whole Blood ◽  
Oxygen Affinity ◽  
Hill Coefficient ◽  
Human Whole Blood ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
The Hill ◽  
Good Agreement

Oxygen dissociation curves of partially CO-saturated human whole blood drawn freshly or preserved more than 3 wk were studied. With increasing CO-hemoglobin concentrations, oxygen affinity of the blood increased and the Hill coefficient, n, fell and gradually approached unity. The changes induced by CO-hemoglobin showed practically no difference in the presence or absence of 2,3-diphosphoglycerate. The Bohr coefficient, deltalog P50/deltapH, was determined as a function of oxygen saturation for various concentrations of CO-hemoglobin. The coefficient remained essentially unchanged in the presence of CO-hemoglobin. In the presence of less than 50% CO-hemoglobin, a good agreement was observed between the observed oxygen dissociation curves and the curves calculated according to Roughton and Darling (Am. J. Physiol. 141: 17-31, 1944). Based on these results, physiological implications of carboxyhemoglobinemia are discussed quantitatively in comparison with methemoglobinemia.

Human whole-blood oxygen affinity: effect of carbon monoxide

1984 ◽  
Vol 57 (1) ◽  
pp. 14-20 ◽  
Author(s):  
A. Zwart ◽  
G. Kwant ◽  
B. Oeseburg ◽  
W. G. Zijlstra
Keyword(s):  
Carbon Monoxide ◽  
Whole Blood ◽  
Saturation Pressure ◽  
Oxygen Affinity ◽  
Gradual Change ◽  
Blood Oxygen ◽  
Human Whole Blood ◽  
Oxygen Dissociation ◽  
Blood Oxygen Affinity ◽  
Dissociation Curves

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.

scholarly journals Control of oxygen affinity of hemoglobin in K562 cells induced by hemin

Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1447-1452 ◽  
Author(s):  
Y Wu ◽  
A Dean ◽  
W Egan ◽  
AN Schechter
Keyword(s):  
Time Course ◽  
31P Nmr ◽  
Oxygen Affinity ◽  
K562 Cells ◽  
Hill Coefficient ◽  
Oxygen Dissociation ◽  
Oxygen Affinity Of Hemoglobin ◽  
Dissociation Curves ◽  
The Relationship ◽  
2,3 Dpg

Abstract The oxygen affinity of hemoglobin in K562 cells induced by hemin and the relationship between levels of 2,3-diphosphoglycerate (2,3-DPG) and hemoglobin have been investigated. Absorption spectra of induced cells indicate that the hemoglobin is oxygenated; oxygen dissociation curves are symmetric, with a P50 of 20 +/- 0.9 mm Hg, Hill coefficient of 2.5, and a normal temperature dependence. The intracellular pH measured by phosphorus 31 nuclear magnetic resonance (NMR) was 7.3. The amount of 2,3-DPG was determined by an enzymatic method and by 31P NMR. The level of 2,3-DPG in uninduced K562 cells, containing 0.5 pg of hemoglobin per cell, was low (5 +/- 0.5 mumole/10(8) cells), but increased to 64 +/- 5 mumole/10(8) cells upon induction of hemoglobin accumulation (to a final level of 20 pg hemoglobin/cell). For several experiments, there was a closely coordinated relationship between 2,3-DPG and hemoglobin levels, at about 1:1 stoichiometry of the two molecules. The time course of induction of hemoglobin, and of 2,3-DPG levels, are very similar; both processes are reversible. These data suggest that induction of hemoglobin synthesis in K562 cells by hemin results in hemoglobin-containing cells with normal oxygenation properties and that 2,3-DPG and hemoglobin levels are coordinately controlled in these cells. Elucidation of the mechanism of this effect should be of importance in understanding the erythroid-like differentiation of these cells.

Investigation of the Molecular Basis of High Oxygen Affinity Hemoglobin Brigham (α2Aβ2100 Pro→Leu) In a Subject with Familial Erythrocytosis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4806-4806
Author(s):  
Bindu Abraham ◽  
Yiping Jia ◽  
Francine Wood ◽  
Chad Reiter ◽  
Jay Nelson Lozier ◽  
...  
Keyword(s):  
Amino Acid ◽  
Whole Blood ◽  
Conflicts Of Interest ◽  
Ph Dependence ◽  
Oxygen Affinity ◽  
Blood Substitutes ◽  
High Oxygen ◽  
Hill Coefficient ◽  
Oxygen Dissociation ◽  
High Oxygen Affinity

Abstract Abstract 4806 A 40 year old female was seen at the NIH Clinical Center for polycythemia (Hb 16.3 g/dL) and recurrent pulmonary embolism. It was determined that she was a member of the original kindred with familial erythrocytosis due to the high oxygen affinity Hb Brigham first reported by Lokich et al (JCI, 1973;52:2060-7) where leucine replaces proline at amino acid 100 in the Hb beta globin chain. We sought to isolate and characterize the abnormal Hb in order to elucidate the mechanism by which the amino acid substitution causes a high affinity for oxygen. Fresh RBCs exhibited high oxygen affinity (P50 = 23.6 mmHg; a Hill coefficient of n=2.02) compared to that of fresh normal RBCs (P50 = 31.1 mmHg; n=2.1) in Hemox buffer, pH 7.4 at 37°C using the TCS automated Hemox analyzer. After 2, 3-diphosphoglycerate (DPG) depletion (24 hours incubation of RBCs at room temp) the RBCs exhibited a higher oxygen affinity, that decreased when inositol hexaphosphate (a 2, 3-DPG analogue) was electroporated into erythrocytes, indicating a normal allosteric response at the 2,3-DPG binding site. The Bohr effect (pH dependence of oxygen affinity) of stripped Hb Brigham was reduced by approximately 30% when compared to that of HbA0. Hb Brigham was separated from Hb A in this subject using strong cationic HPLC and the molecular composition of each protein was verified by tryptic peptide mapping and mass spectrometry of purified peptides. The purified fractions; F1 (HbA0) and FII (Hb Brigham) which represent approximately 60% and 40% of total Hb, respectively, were characterized using rapid mixing stopped-flow kinetics and compared to RBCs Brigham. The time course of the oxygen dissociation reaction from both (oxy) fractions in the presence of sodium dithionite were monophasic with apparent rate constants derived for FI (koff = 38 s-1) which is comparable to that of whole blood (koff = 37.9 s-1) and that of normal control HbAo (koff = 39.6 s-1). However, the rate constant for oxygen dissociation from FII was slightly reduced (koff = 33.9 s-1). To further characterize oxygen dissociation kinetics, carbon monoxide (CO) combination kinetics with the (deoxy) forms of each hemoglobin were also carried out. The kinetics of CO binding to deoxyHb were comparable between both purified fractions and whole blood (kon =0.22-0.23 mM-1 s-1). Unlike FI or control Hb A0, FII showed no change in its CO binding kinetics in the presence of increasing concentrations of IHP. We propose that the IHP-dependent difference in CO binding resulted from destabilization of the deoxy (tense) structure due to the β2 100 Pro→Leu substitution. Analysis of purified Hb Brigham, which was not previously possible, provides valuable insights into the contribution of this mutant to the overall oxygen affinity in this patient and may be useful in the design and evaluation of hemoglobin-based blood substitutes. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Reliability of the determination of whole-blood oxygen affinity by means of blood-gas analyzers and multi-wavelength oximeters.

1989 ◽  
Vol 35 (5) ◽  
pp. 773-777 ◽  
Author(s):  
G Kwant ◽  
B Oeseburg ◽  
W G Zijistra
Keyword(s):  
Whole Blood ◽  
Carbon Monoxide Poisoning ◽  
Oxygen Affinity ◽  
Reference Interval ◽  
Accurate Method ◽  
Blood Gas ◽  
Oxygen Dissociation ◽  
Multi Wavelength ◽  
Dissociation Curves

Abstract Determination of the oxygen affinity of human whole blood with the help of blood-gas analyzers and multi-wavelength oximeters is compared with an accurate method for recording hemoglobin oxygen dissociation curves (Clin Chem 1982;28:1287-92). P50 (oxygen tension at half saturation; So2 = 50%) and Hill's n (delta log [So2/(1-So2)]/delta log Po2) were determined in blood of 24 healthy donors. Three slightly different procedures were used for determination of P50 on the basis of Po2, pH, Pco2, and So2 measured with each of four different blood-gas analyzer/oximeter combinations. These methods were not able to discriminate between high and low values for P50 within the normal reference interval, but never failed to detect the high oxygen affinity of blood stored for 12 days, reflected in low values of P50. The methods thus proved suitable for detecting clinically significant deviations in oxygen affinity such as occur in patients with, e.g., abnormal hemoglobins, anemias, or carbon monoxide poisoning. Determination of Hill's n by these methods did not produce useful results.

scholarly journals Control of oxygen affinity of hemoglobin in K562 cells induced by hemin

Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1447-1452
Author(s):  
Y Wu ◽  
A Dean ◽  
W Egan ◽  
AN Schechter
Keyword(s):  
Time Course ◽  
31P Nmr ◽  
Oxygen Affinity ◽  
K562 Cells ◽  
Hill Coefficient ◽  
Oxygen Dissociation ◽  
Oxygen Affinity Of Hemoglobin ◽  
Dissociation Curves ◽  
The Relationship ◽  
2,3 Dpg

The oxygen affinity of hemoglobin in K562 cells induced by hemin and the relationship between levels of 2,3-diphosphoglycerate (2,3-DPG) and hemoglobin have been investigated. Absorption spectra of induced cells indicate that the hemoglobin is oxygenated; oxygen dissociation curves are symmetric, with a P50 of 20 +/- 0.9 mm Hg, Hill coefficient of 2.5, and a normal temperature dependence. The intracellular pH measured by phosphorus 31 nuclear magnetic resonance (NMR) was 7.3. The amount of 2,3-DPG was determined by an enzymatic method and by 31P NMR. The level of 2,3-DPG in uninduced K562 cells, containing 0.5 pg of hemoglobin per cell, was low (5 +/- 0.5 mumole/10(8) cells), but increased to 64 +/- 5 mumole/10(8) cells upon induction of hemoglobin accumulation (to a final level of 20 pg hemoglobin/cell). For several experiments, there was a closely coordinated relationship between 2,3-DPG and hemoglobin levels, at about 1:1 stoichiometry of the two molecules. The time course of induction of hemoglobin, and of 2,3-DPG levels, are very similar; both processes are reversible. These data suggest that induction of hemoglobin synthesis in K562 cells by hemin results in hemoglobin-containing cells with normal oxygenation properties and that 2,3-DPG and hemoglobin levels are coordinately controlled in these cells. Elucidation of the mechanism of this effect should be of importance in understanding the erythroid-like differentiation of these cells.

Influence of carbon monoxide on hemoglobin-oxygen binding

1976 ◽  
Vol 41 (6) ◽  
pp. 893-899 ◽  
Author(s):  
M. P. Hlastala ◽  
H. P. McKenna ◽  
R. L. Franada ◽  
J. C. Detter
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Affinity ◽  
Co2 Concentration ◽  
Bohr Effect ◽  
Oxygen Binding ◽  
Dissociation Curve ◽  
Low Oxygen ◽  
Oxygen Dissociation ◽  
Initial Binding ◽  
Fixed Acid

The oxygen dissociation curve and Bohr effect were measured in normal whole blood as a function of carboxyhemoglobin concentration [HbCO]. pH was changed by varying CO2 concentration (CO2 Bohr effect) or by addition of isotonic NaOH or HCl at constant PCO2 (fixed acid Bohr effect). As [HbCO] varied through the range of 2, 25, 50, and 75%, P50 was 26.3, 18.0, 11.6, and 6.5 mmHg, respectively. CO2 Bohr effect was highest at low oxygen saturations. This effect did not change as [HbCO] was increased. However, as [HbCO] was increased from 2 to 75%, the fixed acid Bohr factor increased in magnitude from -0.20 to -0.80 at very low oxygen saturations. The effect of molecular CO2 binding (carbamino) on oxygen affinity was eliminated at high [HbCO]. These results are consistent with the initial binding of O2 or CO to thealpha-chain of hemoglobin. The results also suggest that heme-heme interaction is different for oxygen than for carbon monoxide.

scholarly journals The effect of temperature on the oxygen dissociation curves of whole blood of larval and adult lampreys (Geotria australis)

1982 ◽  
Vol 97 (1) ◽  
pp. 253-261
Author(s):  
D. J. Macey ◽  
I. C. Potter
Keyword(s):  
Whole Blood ◽  
Life Cycle Stage ◽  
Effect Of Temperature ◽  
High Affinity ◽  
Oxygen Dissociation ◽  
Geotria Australis ◽  
Oxygen Tensions ◽  
Dissociation Curves ◽  
Hill Plots ◽  
Very High

1. Oxygen dissociation curves of the whole blood of larvae and adults of the Southern Hemisphere lamprey Geotria australis have been determined between pH 6.8 and 8.2 at 5, 15 and 25 degrees C. 2. The P50's at temperatures of 5, 15 and 25 degrees C and a pH of 7.75 were respectively 0.57, 0.92 and 1.19 mmHg in larvae and 6.9, 10.3 and 19.0 mmHg in adults. 3. The relatively very high affinity of larval blood for oxygen may reflect an adaptation to low environmental oxygen tensions. 4. The Bohr shift was not significantly affected by either temperature or life-cycle stage. 5. The slope (n) in Hill plots increased with temperature and oxygen saturation, and was greater in adults than in larvae.

Myoglobin oxygen dissociation by multiwavelength spectroscopy

1997 ◽  
Vol 82 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Kenneth A. Schenkman ◽  
David R. Marble ◽  
David H. Burns ◽  
Eric O. Feigl
Keyword(s):  
Least Squares ◽  
Hill Equation ◽  
Oxygen Binding ◽  
Dissociation Curve ◽  
Nitrogen Gas ◽  
Binding Characteristics ◽  
Oxygen Fraction ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
The Hill

Schenkman, Kenneth A., David R. Marble, David H. Burns, and Eric O. Feigl. Myoglobin oxygen dissociation by multiwavelength spectroscopy. J. Appl. Physiol. 82(1): 86–92, 1997.—Multiwavelength optical spectroscopy was used to determine the oxygen-binding characteristics for equine myoglobin. Oxygen-binding relationships as a function of oxygen tension were determined for temperatures of 10, 25, 35, 37, and 40°C, at pH 7.0. In addition, dissociation curves were determined at 37°C for pH 6.5, 7.0, and 7.5. Equilibration was achieved with a myoglobin solution, at the desired temperature and pH, and 16 oxygen-nitrogen gas mixtures of known oxygen fraction. Correction for the inevitable presence of metmyoglobin was made by using a three-component least squares analysis and by correcting the end point oxymyoglobin spectra for the presence of metmyoglobin. The[Formula: see text] at which myoglobin is half-saturated with O2(P50) was determined to be 2.39 Torr at pH 7.0 and 37°C. The myoglobin dissociation curve was well fit by the Hill equation [saturation =[Formula: see text]/([Formula: see text]+ P50)].

The in vitro respiratory and acid–base properties of blood and tissue from the Kemp's ridley sea turtle, Lepidochelys kempi

1994 ◽  
Vol 72 (8) ◽  
pp. 1403-1408 ◽  
Author(s):  
Erich K. Stabenau ◽  
Thomas A. Heming
Keyword(s):  
Temperature Sensitivity ◽  
Whole Blood ◽  
Sea Turtles ◽  
Hill Coefficient ◽  
Acid Base ◽  
Kemp's Ridley Sea Turtles ◽  
Dissociation Curves ◽  
Kemp's Ridley ◽  
Base Properties

We determined the in vitro respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles (Lepidochelys kempi). Blood O2 dissociation curves of ridley turtles were sigmoid, with a P50 of 31.2 ± 0.3 (mean ± SD) torr at 25 °C and pH 7.51. Increments in temperature or [Formula: see text] were associated with a shift of the O2 dissociation curves to the right and, hence, a reduction in haemoglobin–O2 binding affinity. The apparent heat of oxygenation, which is a measure of the temperature sensitivity of haemoglobin–O2 affinity, was −10.5 kcal/mol O2. The degree of cooperativity of O2 for hemoglobin binding sites, as measured by the Hill coefficient, increased at higher temperatures (20–30 °C at a [Formula: see text] of 37 torr), but was unaffected by changes in [Formula: see text] (37–52 torr at 25 °C). The CO2-Bohr effect was −0.34 torr/pH unit. The CO2 capacitance coefficient of whole blood and plasma declined as a function of increased [Formula: see text] (22 °C). Non-bicarbonate buffer capacities (22 °C) were 19.7, 18.5, and 6.4 slykes for whole blood, true plasma, and separated plasma, respectively. The skeletal muscle myoglobin content was 3.1 ± 0.84 mg∙g−1 of tissue. The respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles are consistent with those of species that utilize lung O2 stores during long-term aerobic dives. The enhanced haemoglobin–O2 temperature sensitivity exhibited by the ridley turtle could be a physiological adaptation for life in coastal environments that typically undergo substantial fluctuations in temperature.

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