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.

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.
References in periodicals archive ?
In oximetry, the isobestic points of oxyhaemoglobin and deoxyhaemoglobin occur at 590 nm and 805 nm.
Oxyhaemoglobin and deoxyhaemoglobin absorb light in the 650 - 1 000 nm wavelength range, and attenuate measurements of light transmitted through tissue.
Oxidised low density lipoproteins convert oxyhaemoglobin from ruptured erythrocytes to reactive ferryl forms.
We observed that all children had an oxyhaemoglobin saturation of 98-100% (30-45) minutes after premedication; and there was no delayed recovery from anesthesia in any patient.
The latter includes detection of flow, measurement of oxyhaemoglobin saturation and detection of respiratory effort.
Standard monitors (electrocardiograph, non-invasive blood pressure and pulse oximetry for arterial oxyhaemoglobin saturation, Sp[O.
CO binds to haemoglobin 225 times more avidly than oxygen, and causes a left shift in the oxyhaemoglobin dissociation curve (decreased [P.
A hypopnoea is defined as a reduction in airflow (30-50%) that is followed by an arousal from sleep or a decrease in oxyhaemoglobin saturation (3-4%) (5,6).
In the operating room, non-invasive measurements of electrocardiogram, oxyhaemoglobin saturation (Sp[O.
2] and a very small decrease in oxygen-carrying capacity, as it is on the flat part of the oxyhaemoglobin dissociation curve.
These include total sleep time, wakefulness after sleep onset, number of awakenings, arousal index, average oxyhaemoglobin saturation during sleep, and the presence of daytime sleepiness, snoring, and loud snoring.