The Experts below are selected from a list of 1890 Experts worldwide ranked by ideXlab platform
Gunnar Lykkeboe - One of the best experts on this subject based on the ideXlab platform.
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the magnitude of the bohr Effect profoundly influences the shape and position of the blood oxygen equilibrium curve
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2021Co-Authors: Hans Malte, Gunnar Lykkeboe, Tobias WangAbstract:For the past century, the importance of the Bohr Effect for blood oxygen delivery has been deemed secondary to the influence of the uptake of carbon dioxide when the blood is deoxygenated (the Haldane Effect). This is, however, not the case. The simultaneous oxygen and proton binding to hemoglobin can be modelled by a two-ligand, two-state formulation, while the resulting changes in acid-base status of the surrounding solution can be assessed according to Stewart's model for strong ion difference. This approach shows that an abolishment of the Bohr Effect (by either equalizing pKa values of the Bohr groups of T and R states, or by removing the Bohr groups in the calculations) dramatically increases oxygen affinity, and that the Bohr Effect plays a crucial role in determining the overall position and shape of the oxygen equilibrium curve. Thus, the magnitude of the Bohr Effect (the Bohr factor) and oxygen affinity are directly related, and any change in hemoglobin structure that affects the Bohr factor will inevitably influence hemoglobin oxygen affinity. The modelling approach also emphasizes that pH, PCO2 and PO2 in capillaries are dependent variables, determined by arterial blood gases, the Bohr Effect, the respiratory quotient (RQ) of tissue metabolism and the buffer capacity of blood. Thus, the full extent of the Bohr Effect cannot be appreciated by comparing oxygen equilibrium curves made at constant PCO2 or pH, but only by comparing curves at constant proton saturation of the Bohr groups. This is because, it is the protons bound to the Bohr groups that directly influence hemoglobin‑oxygen binding.
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the bohr Haldane Effect a model based uncovering of the full extent of its impact on o2 delivery to and co2 removal from tissues
Journal of Applied Physiology, 2018Co-Authors: Hans Malte, Gunnar LykkeboeAbstract: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 ...
Hans Malte - One of the best experts on this subject based on the ideXlab platform.
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the magnitude of the bohr Effect profoundly influences the shape and position of the blood oxygen equilibrium curve
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2021Co-Authors: Hans Malte, Gunnar Lykkeboe, Tobias WangAbstract:For the past century, the importance of the Bohr Effect for blood oxygen delivery has been deemed secondary to the influence of the uptake of carbon dioxide when the blood is deoxygenated (the Haldane Effect). This is, however, not the case. The simultaneous oxygen and proton binding to hemoglobin can be modelled by a two-ligand, two-state formulation, while the resulting changes in acid-base status of the surrounding solution can be assessed according to Stewart's model for strong ion difference. This approach shows that an abolishment of the Bohr Effect (by either equalizing pKa values of the Bohr groups of T and R states, or by removing the Bohr groups in the calculations) dramatically increases oxygen affinity, and that the Bohr Effect plays a crucial role in determining the overall position and shape of the oxygen equilibrium curve. Thus, the magnitude of the Bohr Effect (the Bohr factor) and oxygen affinity are directly related, and any change in hemoglobin structure that affects the Bohr factor will inevitably influence hemoglobin oxygen affinity. The modelling approach also emphasizes that pH, PCO2 and PO2 in capillaries are dependent variables, determined by arterial blood gases, the Bohr Effect, the respiratory quotient (RQ) of tissue metabolism and the buffer capacity of blood. Thus, the full extent of the Bohr Effect cannot be appreciated by comparing oxygen equilibrium curves made at constant PCO2 or pH, but only by comparing curves at constant proton saturation of the Bohr groups. This is because, it is the protons bound to the Bohr groups that directly influence hemoglobin‑oxygen binding.
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the bohr Haldane Effect a model based uncovering of the full extent of its impact on o2 delivery to and co2 removal from tissues
Journal of Applied Physiology, 2018Co-Authors: Hans Malte, Gunnar LykkeboeAbstract: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 ...
Antonio R Delgadoalmeida - One of the best experts on this subject based on the ideXlab platform.
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from bohr Haldane Effect on hb o2 binding to electrical regeneration in chd
The FASEB Journal, 2012Co-Authors: Antonio R DelgadoalmeidaAbstract:Background: Despite extensive clinical and basic research, the precise mechanism for Hb-O2 binding remains to be determined. Since we have confirmed that RBC K rapidly reverses angina, ST-T alterations, and induces electrical regeneration of heart in CHD, we tested the hypothesis that RBC K transport is involved on Hb-O2 binding in human RBC. Methods/Subjects: Heparin venous sample from healthy subjects were analyzed before (4 ml) and after in Vitro oxygenation (4 ml +1ml 100% O2). In all pH, PO2/PCO2, HCO3 (Stat Profile pHOx), RBC/plasma electrolytes (Na, K, Atomic Emission Spectrophotometry), Cl (Lytek-Cl). Statistical using Student’s t-test, analysis of variance, p<0.05 as exponential values. Results: In Vitro blood oxygenation (O2 Sat 87±3 vs 47±6%) resulted in sharply decreased RBC K (Ki) )87.6± 2.3 vs 92.0±2.3 mmol/lcell, p<4.5E-09), RBC Nai (5.8±0.2 vs 6.3±0.2 mmol/lcell, p<6.5E-05) along with plasma K (3.3 ±0.3 vs 3.8±0.2 mmol/l, p<9.7E-05), Na (134±4 vs 139±2.2, p<1.3E-03) and Cl (91±1.6 vs 98.3±1.2 mmol/l, p<7.9E-11), uncovering a complex biochemical event in Hb-O2 binding and Bohr Effect, which excludes a simple gas diffusion. Conclusion: This observation strongly supports our novel therapeutic approach improving RBC K, and probably myocardial O2 transport in CHD. Second, it is proposed that RBC K exchange should be included in evaluation of Bohr-Haldane Effects in clinical and experimental human Hb-O2 exchanges.
Felix A H Sperling - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial dna variation and Haldane s rule in the papilio glaucus and p troilus species groups
Heredity, 1993Co-Authors: Felix A H SperlingAbstract:Variation in mitochondrial DNA (mtDNA) was surveyed, using restriction endonucleases, in all species of the Papilio glaucus and P. troilus groups (Lepidoptera: Papilionidae). Phylogenetic and distance relationships of mtDNA generally confirmed traditional species limits in the two species groups and compared favourably with a prior survey of their allozymes. The most notable exceptions were P. rutulus and P. eurymedon, which share their mtDNA, yet maintain numerous morphological and ecological distinctions in sympatry. In organisms with heterogametic females, like the Lepidoptera, the deficiencies of hybrid females that are expected on the basis of Haldane's rule should lead to congruence of mtDNA variants with species boundaries. In the P. glaucus group, the extent of mtDNA differences between species pairs generally coincided with the extent of the Haldane Effect, as well as with the presence of major species differences on sex chromosomes (X Effect).
Tobias Wang - One of the best experts on this subject based on the ideXlab platform.
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the magnitude of the bohr Effect profoundly influences the shape and position of the blood oxygen equilibrium curve
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2021Co-Authors: Hans Malte, Gunnar Lykkeboe, Tobias WangAbstract:For the past century, the importance of the Bohr Effect for blood oxygen delivery has been deemed secondary to the influence of the uptake of carbon dioxide when the blood is deoxygenated (the Haldane Effect). This is, however, not the case. The simultaneous oxygen and proton binding to hemoglobin can be modelled by a two-ligand, two-state formulation, while the resulting changes in acid-base status of the surrounding solution can be assessed according to Stewart's model for strong ion difference. This approach shows that an abolishment of the Bohr Effect (by either equalizing pKa values of the Bohr groups of T and R states, or by removing the Bohr groups in the calculations) dramatically increases oxygen affinity, and that the Bohr Effect plays a crucial role in determining the overall position and shape of the oxygen equilibrium curve. Thus, the magnitude of the Bohr Effect (the Bohr factor) and oxygen affinity are directly related, and any change in hemoglobin structure that affects the Bohr factor will inevitably influence hemoglobin oxygen affinity. The modelling approach also emphasizes that pH, PCO2 and PO2 in capillaries are dependent variables, determined by arterial blood gases, the Bohr Effect, the respiratory quotient (RQ) of tissue metabolism and the buffer capacity of blood. Thus, the full extent of the Bohr Effect cannot be appreciated by comparing oxygen equilibrium curves made at constant PCO2 or pH, but only by comparing curves at constant proton saturation of the Bohr groups. This is because, it is the protons bound to the Bohr groups that directly influence hemoglobin‑oxygen binding.
