Oxyhemoglobin


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oxyhemoglobin

[¦äk·sē′hē·mə‚glō·bən]
(biochemistry)
The red crystalline pigment formed in blood by the combination of oxygen and hemoglobin, without the oxidation of iron.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Oxyhemoglobin

 

the oxygenated form of hemoglobin (HbO2) that results from the reversible combination of oxygen and reduced hemoglobin (Hb). Oxyhemoglobin carries O2 from the respiratory organs to the tissues and imparts a bright red color to arterial blood. The O2 molecule is bonded to Hb by the Fe2+ atom in heme; the valence of Fe2+ remains unchanged during this process, that is, no actual oxidation takes place. The combination of O2 with one of the four heme groups alters the three dimensional Hb structure and the affinity of the remaining heme groups for O2.

The formation and dissociation of oxyhemoglobin are influenced by several factors, including CO2 concentration and pH. The structure of heme in the Hb molecule is the same for all animals, but the protein fraction—globin—differs from species to species in size, amino-acid composition, and physical properties. The structure of globin is another factor that affects the affinity of Hb for O2. Species differences in globin structure are associated with natural habitat: in general, an increase in the supply of available O2 decreases the affinity of Hb for O2 and consequently increases the partial pressure of O2; this increase is necessary to effect Hb saturation and formation of HbO2. For example, the Hb of land animals exhibits a lower affinity for O2 than that of aquatic animals; fishes that inhabit running water have Hb with a lower O2 affinity than species dwelling in stagnant water. A given species may even have several Hb types, which replace each other during ontogenesis; for example, HbO2 forms more readily in the human fetus than in the adult.

REFERENCES

Prosser, L., and F. Brown. Sravnitel’naia fiziologiia zhivotnykh. Moscow, 1967. Pages 238–79. (Translated from English.)
Korzhuev, P. A. “Problema oksigenatsii gemoglobina.” Uspekhi fiziologicheskikh nauk, 1973, vol. 4, no. 3.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Second, time interval between symptom onset and radioexaminiation, hyperacute clot might not be show as hypointense signal on SWI, as the oxyhemoglobin remains the original status, instead of turning into deoxyhemoglobin or hemosiderin.
Tyuma, "Stoichiometry of the reaction of oxyhemoglobin with nitrite," BBA--Protein Structure, vol.
Caption: Figure 5: (a) Grand average time courses of changes in deoxyhemoglobin (A[HbRj) and oxyhemoglobin ([DELTA][HbO]).
Thus, the percentage of oxyhemoglobin in the blood was reduced by 21.8% and relative ability of hemoglobin to drop off ligands by 16.9% in comparison with the control group (p < 0.05).
Once synthesized, NO is rapidly oxidized to nitrite (N[O.sub.2.sup.-]) or by ceruloplasmin and the N[O.sub.2.sup.-] formed also can be oxidized or suffer action of oxyhemoglobin to generate N[O.sub.3.sup.-].
When you inhale, oxygen reaching your lungs combines with the hemoglobin in your red blood cells to form oxyhemoglobin. The oxygen is transported throughout your body by your arteries and capillaries and then disassociates from the blood to oxygenate the cells of your tissues and organs.
Within first few hours of its origin (0-24 hours), due to high content of intracellular oxyhemoglobin, hematoma appears bright on T2-weighted (T2-W) and isointense on T1-wighted (T1-W) images.
Decreases in PaO2 rarely exceed 10 mmHg, and the PaO2 values tend to be on the flat portion of the oxyhemoglobin curve, so that drops in arterial oxygen saturation (SaO2) are minimized.
(12) Since methylene blue has a peak light absorption that closely corresponds to the light absorption of deoxyhemoglobin, it is believed that the artifactual desaturation is due to the difference in light absorption between deoxyhemoglobin and oxyhemoglobin. Neither pseudocyanosis nor methemoglobinemia is associated with skin injury.
The oxyhemoglobin saturation reached 55-60% in mice at [FIO.sub.2] of 6-7%.
Oxyhemoglobin saturation, a measure of oxygen in the blood, was low (89 percent).
They come in two types: oxyhemoglobin (OH) carry oxygen and deoxyhemoglobin (DH) are those that have delivered their oxygen.