A Mathematical Treatment of the Blood Dissociation Curve for Oxygen

1963 ◽  
Vol 9 (6) ◽  
pp. 745-762 ◽  
Author(s):  
Rodolfo Margaria
Keyword(s):  
Dissociation Constants ◽  
Quantitative Description ◽  
Mathematical Treatment ◽  
Physiological Effects ◽  
Functional Importance ◽  
Acidic Group ◽  
Oxygen Dissociation ◽  
Dissociation Curves

Abstract A quantitative description of Bohr's effect can be made from the oxygen dissociation curves of hemoglobin at different pHs, and the dissociation constants of the 02-linked acidic group of Hb (KR) and Hb02 (Ko) have been calculated as, respectively, 1.29 1O-8 and 3.42 10-7 at37°. On the assumption that the oxygenation of hemoglobin takes place in four successive steps, the constant for each equilibrium can easily be calculated, and the values given. It appears that the oxygenation takes place with the same affinity for the first three steps, while the affinity for the fourth oxygenation is 125 times greater. On the basis of these results a simplification of Adair's formula is given, containing only two constants, one (K) being representative of the affinity of the oxygen for the first three hemes, and the other (in)being the increase of affinity for the fourth oxygenation. This formula seems to fit most data in the literature of hemoglobin solutions and of blood in vivo and in vitro. The physiological effects and the functional importance of the increased affinity for the fourth oxygenation are described, and the possibility that disturbances of the Hb oxygenation process may be due to the lack of this process is considered.

Bohr effect and slope of the oxygen dissociation curve after physical training

1982 ◽  
Vol 52 (6) ◽  
pp. 1524-1529 ◽  
Author(s):  
K. M. Braumann ◽  
D. Boning ◽  
F. Trost
Keyword(s):  
Venous Blood ◽  
Training Period ◽  
Dissociation Curve ◽  
Period Increase ◽  
Oxygen Dissociation ◽  
Small Rise ◽  
Dissociation Curves ◽  
O2 Dissociation

Three O2 dissociation curves from venous blood [taken at rest (A), after in vitro acidification with lactic acid (B), and after exhaustive exercise (C)] were determined in eight athletes twice in a year in detrained and fully trained state. The steepness of the standard O2 dissociation curve becomes greater during the training period (increase in Hill's n from 2.68 +/- 0.10 to 2.96 +/- 0.15). There was a concomitant small rise in the intraerythrocytic organic phosphate concentrations. Bohr coefficients (BC) were calculated for blood O2 saturations ranging from 10 to 80% by comparing the dissociation curves A and B (“in vitro” BC) and curves A and C (“in vivo” BC). In detrained and trained state the in vivo BC show their maximal values at low saturation levels, in contrast the in vitro BC exhibit maximal values at middle saturations. During the training period there was an increase in the in vivo BC as well as in the in vitro BC at low saturations. These alterations may lead to augmented O2 extraction from a given volume of blood by up to 15% during heavy work in trained state. The reason for these observations could be an altered erythrocyte population.

The Lack of Effects of Phototherapy on Neonatal Oxygen Dissociation Curves and Hemoglobin Concentration in Vivo

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 1027-1031
Author(s):  
Barry D. Chandler ◽  
William J. Cashore ◽  
Pierre J. P. Monin ◽  
William Oh
Keyword(s):  
Serum Bilirubin ◽  
Hemoglobin Concentration ◽  
Control Group ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Right ◽  
Dissociation Curves ◽  
2,3 Dpg

Phototherapy has been shown to cause hemolysis of fetal red cells and a shift to the right in the neonatal oxygen dissociation curve (ΔP50) in vitro. To determine if these parameters act similarly in vivo, we have studied 16 icteric infants before and after phototherapy and compared them with eight control infants studied at birth and at 3 days of age, measuring the change in P50, 2,3-diphosphoglycerate (2,3-DPG), serum bilirubin, the percent of bilirubin/albumin saturation, and the hemoglobin concentration in the two groups. Following phototherapy, in the icteric infants there was a shift to the right in the O2 dissociation curve of + 1.7 mm Hg, a rise in 2,3-DPG of 2.26 µmol/gm Hb, a fall in serum bilirubin of 4.3 mg/100 ml, a decrease in percent bilirubin/albumin saturation of 12.4%, and a drop in hemoglobin of 1.1 gm/100 ml. The control group showed a ΔP50 of + 2.0 mm Hg, a rise in 2,3-DPG of 3.67 µmol/gm Hb, an increase in serum bilirubin of 3.2 mg/100 ml, an increase in percent bilirubin/albumin saturation of 9.3%, and a fall in hemoglobin of 0.3 gm/100 ml. Significant differences between the groups were seen only in the changes in bilirubin concentration and percent bilirubin/albunmin saturation. The magnitude of changes in P50, 2,3-DPG, and hemoglobin concentration was similar in the phototherapy and control groups and was related to the expected changes with reference to postnatal age. These results suggest that phototherapy in vivo neither affects fetal erythrocytic affinity for oxygen nor causes hemolysis.

scholarly journals Oxygen dissociation curves of rat blood in vitro and in vivo

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Timothy B. Bentley ◽  
Bozena Kowalska ◽  
Niluka Wickramaratne
Keyword(s):  
Rat Blood ◽  
Oxygen Dissociation ◽  
Dissociation Curves

Bioavailability in Vivo of Benzo[a]Pyrene Adsorbed to Diesel Particulate

1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio
Keyword(s):  
Health Risks ◽  
Quantitative Description ◽  
Intratracheal Instillation ◽  
Direct Analysis ◽  
Sprague Dawley ◽  
Reasonable Estimate ◽  
Diesel Particulate ◽  
Sprague Dawley Rats

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.

scholarly journals Oxygen and Carbon Dioxide Transport Characteristics of the Blood of the Nile Monitor Lizard (Varanus Niloticus)

1987 ◽  
Vol 130 (1) ◽  
pp. 27-38
Author(s):  
JAMES W. HICKS ◽  
ATSUSHI ISHIMATSU ◽  
NORBERT HEISLER
Keyword(s):  
Carbon Dioxide ◽  
Haemoglobin Concentration ◽  
Oxygen Affinity ◽  
Total Blood ◽  
Carbon Dioxide Transport ◽  
Monitor Lizard ◽  
The Right ◽  
Dissociation Curves

Oxygen and carbon dioxide dissociation curves were constructed for the blood of the Nile monitor lizard, Varanus niloticus, acclimated for 12h at 25 and 35°C. The oxygen affinity of Varanus blood was low when Pco2 w a s in the range of in vivo values (25°C: P50 = 34.3 at PCOCO2 = 21 mmHg; 35°C: P50 = 46.2 mmHg at PCOCO2 = 35 mmHg; 1 mmHg = 133.3 Pa), and the oxygen dissociation curves were highly sigmoidal (Hill's n = 2.97 at 25°C and 3.40 at 35°C). The position of the O2 curves was relatively insensitive to temperature change with an apparent enthalpy of oxygenation (ΔH) of −9.2kJ mol−1. The carbon dioxide dissociation curves were shifted to the right with increasing temperature by decreasing total CCOCO2 at fixed PCOCO2, whereas the state of oxygenation had little effect on total blood CO2 content. The in vitro buffer value of true plasma (Δ[HCO3−]pl/-ΔpHpl) rose from 12.0 mequiv pH−1−1 at 25°C to 17.5 mequiv pH−11−1 at 35°C, reflecting a reversible increase of about 30% in haemoglobin concentration and haematocrit levels during resting conditions in vivo.

2,5-disubstituted-4-thiazolidinones: Synthesis, anti-inflammatory, free radical scavenging potentials and structural insights through molecular docking

2021 ◽  
Vol 18 ◽  
Author(s):  
Jagseer Singh ◽  
Pooja A Chawla ◽  
Rohit Bhatia ◽  
Shamsher Singh
Keyword(s):  
Free Radicals ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Assay Method ◽  
Acidic Group ◽  
Active Compounds ◽  
Cox 2 ◽  
Anti Inflammatory

: The present work reports synthesis and screening of fifteen 2,5-disubstituted-4-thiazolidinones with different substitutions of varied arylidene groups at imino. The structures of the compounds were confirmed by spectral characterization. The compounds were subjected to in vivo anti-inflammatory and in vitro antioxidant activities. The derivatives possessed remarkable activities quite close to standard drugs used. Unlike conventional non-selective NSAIDs, the synthesized compounds did not contain any acidic group, thereby ensuring a complete cure from ulcers. To further substantiate the claim for safer derivatives, the active compounds were docked against the cyclooxygenase (COX)-2 enzyme. It was found that 4-fluorophenylimino substituent at 2- position and 3-nitro moiety on a 5-benzylidene nucleus of the 4-thiazolidinone derivative fitted in the COX-2 binding pocket. The compounds exhibited remarkable activity in scavenging free radicals, as depicted by the DPPH assay method. The structure-activity relationship was also established in the present work with respect to the nature and position of the substituents. The active compounds were evaluated for drug-like nature under Lipinski’s rule of five, and the toxicity behaviour of active compounds was predicted using ADMETlab software. The compounds have the potential to target degenerative disorders associated with inflammation and the generation of free radicals.

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.

Combining in vitro data and modelling to predict in vivo animal response

2006 ◽  
Vol 34 ◽  
pp. 135-144
Author(s):  
Jan Dijkstra ◽  
James France
Keyword(s):  
Quantitative Description ◽  
Gas Production ◽  
Biological Data ◽  
Mathematical Methods ◽  
Passage Rate ◽  
Fractional Rate ◽  
Microbial Efficiency ◽  
Definition Of

SummaryExisting feed evaluation systems for ruminants assess the feed value in a rather empirical way, with a limited ability to integrate metabolism in a meaningful framework. For the quantitative description of the mechanisms, appropriate biological data can be obtained using in vitro methods. The aim of this paper is to examine the use of modelling and in vitro data to predict digestion processes in vivo. Suitable mathematical methods are required to describe and interpret substrate disappearance profiles or gas production profiles. The derivation of such models is important since this allows a clear definition of the underlying assumptions made. Such assumptions are related to the change in fractional rate of degradation (kd) during incubation that will determine the shape of the profile. Furthermore, the value of the fractional passage rate (kp) is of crucial importance in the prediction of extent of degradation in the rumen. The development and application of models, based on classic microbial growth equations, clearly shows that observed variation in microbial efficiency in batch cultures (including the gas production technique) is not necessarily related to that in vivo. Rather, kp is again a major factor contributing to explanation of variation in microbial efficiency. Similarly, the end products of fermentation (VFA) and the VFA molar proportions can be estimated in vitro, but its direct applicability to the in vivo situation is limited. It is concluded that some potential uses of in vitro techniques are ultimately misleading. Mechanistic models indicate that mechanisms governing microbial efficiency and VFA molar proportions in vitro are not necessarily valid for the in vivo situation. Therefore, the in vitro data cannot be used directly for a uniform system of feed evaluation to predict animal responses. Rather, the in vitro data obtained for substrate degradation may be used in whole rumen models as a basal input value to indicate the degradation potential.

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