scholarly journals ALLOSTERIC CONTROL OF OXYGEN BINDING BY HAEMOGLOBIN DURING EMBRYONIC DEVELOPMENT IN THE CROCODILE CROCODYLUS POROSUS: THE ROLE OF RED CELL ORGANIC PHOSPHATES AND CARBON DIOXIDE

1993 ◽  
Vol 175 (1) ◽  
pp. 15-32 ◽  
Author(s):  
G. C. Grigg ◽  
R. M. G. Wells ◽  
L. A. Beard
Keyword(s):  
Embryonic Development ◽  
Whole Blood ◽  
Marked Effect ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Embryonic Life ◽  
Crocodylus Porosus ◽  
Blood Oxygen Affinity ◽  
2,3 Dpg

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.

Regulation of Blood Oxygen Affinity in the Australian Blackfish Gadopsis Marmoratus: I. Correlations between Oxygen-binding Properties, Habitat and Swimming Behaviour

1982 ◽  
Vol 99 (1) ◽  
pp. 223-243
Author(s):  
G. P. DOBSON ◽  
J. BALDWIN
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Swimming Behaviour ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Low Oxygen ◽  
Binding Properties ◽  
Molar Ratios ◽  
Blood Oxygen Affinity ◽  
Low Oxygen Affinity

1. The regulation of whole blood oxygen affinity in the freshwater blackfish Gadopsis marmoratus Richardson has been examined, and correlations made between oxygen-binding properties and the habitat and swimming behaviour of the fish. 2. Blackfish whole blood has a low oxygen affinity relative to other fish bloods reported in the literature. This is not due to a low oxygen affinity of the stripped haemoglobins, but arises from interactions between haemoglobin and intraerythrocytic modulators. 3. The presence of high concentrations of ATP, and to a lesser extent GTP, in the erythrocyte, together with the effect of these nucleoside triphosphates on the oxygen affinity of haemoglobin solutions at physiological NTP: Hb4 molar ratios, demonstrates that this class of compounds is a major regulator of oxygen affinity in blackfish blood. 4. The oxygen affinities of whole blood and haemoglobin solutions are sensitive to pH, with haemoglobin solutions displaying a relatively large alkaline Bohr coefficient of - 1.05 over the physiologically relevant pH range of 6.5–7.0. 5. Although increasing Pco2, lowers the oxygen affinity of whole blood, it does so only through the effect on pH, as pH-buffered haemoglobin solutions show no oxygen-linked CO2 binding. This lack of oxygen-linked CO2 binding has not been reported for any other naturally occurring vertebrate haemoglobins. 6. Muscle morphology and biochemistry, and behavioural observations, indicate that the blackfish uses anaerobic energy metabolism during rapid swimming and in recovery. 7. It is concluded that the oxygen-binding properties of blackfish blood reflect adaptations for maintaining adequate tissue oxygenation for animals at rest and during slow sustained swimming in waters of high oxygen tensions.

scholarly journals Physiologic features of hemolysis axxociated with altered cation and 2,3-diphosphoglycerate content

Blood ◽  
1978 ◽  
Vol 52 (1) ◽  
pp. 135-141 ◽  
Author(s):  
MM Albala ◽  
NL Fortier ◽  
BE Glader
Keyword(s):  
Water Content ◽  
Whole Blood ◽  
Oxygen Affinity ◽  
Monovalent Cation ◽  
Laboratory Evaluation ◽  
Blood Oxygen ◽  
Cation Composition ◽  
Blood Oxygen Affinity ◽  
Osmotic Effects ◽  
2,3 Dpg

Abstract A hemolytic disorder characterized by altered RBC cation composition (increases Na, decreases K), reduced monovalent cation content (decreased Na + K/liter RBC), and decreased levels of 2,3- diphosphoglycerate (2,3-DPG) is described. The etiology of these RBC abnormalities was not elucidated following extensive laboratory evaluation, although two important physiologic principles were manifested by this case: (1) Hemolysis was relatively well compensated (41% hematocrit) despite a significantly decreased RBC survival (51 Cr t 1/2 = 10.5 days). This effect presumably was due to reduced 2,3-DPG content (1.9 mumol/ml RBC) and the associated increase in whole blood oxygen affinity (P50 = 19.6 mm hg). (2) RBC size and water content were normal in spite of marked cation depletion. This anomaly was thought to reflect the osmotic effects of reduced polyvalent anion (2,3-DPG) content.

scholarly journals Physiologic features of hemolysis axxociated with altered cation and 2,3-diphosphoglycerate content

Blood ◽  
1978 ◽  
Vol 52 (1) ◽  
pp. 135-141
Author(s):  
MM Albala ◽  
NL Fortier ◽  
BE Glader
Keyword(s):  
Water Content ◽  
Whole Blood ◽  
Oxygen Affinity ◽  
Monovalent Cation ◽  
Laboratory Evaluation ◽  
Blood Oxygen ◽  
Cation Composition ◽  
Blood Oxygen Affinity ◽  
Osmotic Effects ◽  
2,3 Dpg

A hemolytic disorder characterized by altered RBC cation composition (increases Na, decreases K), reduced monovalent cation content (decreased Na + K/liter RBC), and decreased levels of 2,3- diphosphoglycerate (2,3-DPG) is described. The etiology of these RBC abnormalities was not elucidated following extensive laboratory evaluation, although two important physiologic principles were manifested by this case: (1) Hemolysis was relatively well compensated (41% hematocrit) despite a significantly decreased RBC survival (51 Cr t 1/2 = 10.5 days). This effect presumably was due to reduced 2,3-DPG content (1.9 mumol/ml RBC) and the associated increase in whole blood oxygen affinity (P50 = 19.6 mm hg). (2) RBC size and water content were normal in spite of marked cation depletion. This anomaly was thought to reflect the osmotic effects of reduced polyvalent anion (2,3-DPG) content.

Postnatal regulation of canine oxygen delivery: erythrocyte components affecting Hb function

1980 ◽  
Vol 238 (1) ◽  
pp. H73-H79 ◽  
Author(s):  
P. A. Mueggler ◽  
G. Jones ◽  
J. S. Peterson ◽  
J. M. Bissonnette ◽  
R. D. Koler ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
Fetal Hemoglobin ◽  
Blood Oxygen ◽  
Oxygen Dissociation ◽  
Affinity Change ◽  
Blood Oxygen Affinity ◽  
Postnatal Change ◽  
2,3 Dpg

A rightward shift in the blood oxygen dissociation curve occurs during the 1st mo of canine life. A detailed peptide analysis indicated that dogs do not have a separate fetal hemoglobin. Other erythrocyte components such as ATP, K+, Na+, and H+ were excluded as significant mediators of the postnatal oxygen affinity change. Erythrocyte 2,3-DPG levels essentially zero in fetal dogs, increased rapidly during the 1st mo of canine life. There was a significant correlation between this postnatal 2,3-DPG increase and the postnatal decrease in blood oxygen affinity. Dialyzed hemolysates of fetal or adult canine blood have the same intrinsic oxygen affinity and the same response to normal adult levels of 2,3-DPG. Furthermore, the magnitude and direction of this 2,3-DPG-induced decrease in oxygen affinity in vitro are comparable to the in vivo postnatal change in oxygen affinity.

scholarly journals Oxygen Affinity in Hemoglobin Köln Disease

Blood ◽  
1972 ◽  
Vol 39 (3) ◽  
pp. 398-406 ◽  
Author(s):  
Frank G. de Furia ◽  
Denis R. Miller
Keyword(s):  
Whole Blood ◽  
Normal Values ◽  
Cell Mass ◽  
Oxygen Affinity ◽  
Red Cell ◽  
Blood Oxygen ◽  
Red Cell Mass ◽  
High Oxygen Affinity ◽  
Blood Oxygen Affinity

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.

Effect of Metrizamide on Whole Blood Oxygen Affinity

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