Respiratory Properties of Blood and Myoglobin in Hummingbirds

Johansen, Kjell; Berger, Martin; Bicudo, J. Eduardo P. W.; A, Ruschi; Almeida, P. J. de

doi:10.1086/physzool.60.2.30158651

Cited by 46 publications

(17 citation statements)

References 29 publications

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“…However, bats have the highest levels of hematocrit measured in mammals and may reach values above 70% in Tadarida brasiliensis and Miniopterus minor. Red blood cells are smaller (Figueroa et al, 2007) and hemoglobin has been found in higher concentrations (18-24 g/100ml blood), similar to that found in hummingbirds (Johansen et al, 1987). Consequently, bats have a transport capacity of oxygen in the blood of 25 to 30%.…”

Section: The Heartsupporting

confidence: 64%

Biomechanical, Respiratory and Cardiovascular Adaptations of Bats and the Case of the Small Community of Bats in Chile

Canals¹,

Iriarte-Díaz²,

Grossi³

2011

Biomechanics in Applications

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Section: The Heartsupporting

confidence: 64%

Biomechanical, Respiratory and Cardiovascular Adaptations of Bats and the Case of the Small Community of Bats in Chile

Canals¹,

Iriarte-Díaz²,

Grossi³

2011

Biomechanics in Applications

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“…The temperature coefficient of whole blood from bar-headed geese (0.028) corresponds to a shift of the P 50 of ~1.84mmHg°C -1 and is: (1) ~24-43% greater than that of other birds examined to date (Danzer and Cohn, 1967;Johansen et al, 1987;Maginniss et al, 1997;Pinshow et al, 1985), (2) 18-50% greater than that of mammals (Reeves et al, 1982;Smale and Butler, 1994;Willford et al, 1990), and (3) not dependent on pH (%CO 2 ) (Fig.1). The Bohr effect was slightly lower than previously reported for the barheaded goose (Black and Tenney, 1980), but similar to that of other birds and mammals Danzer and Cohn, 1967;Grispo et al, 2012;Lutz et al, 1973;Weber and Campbell, 2011), and was not temperature dependent.…”

Section: Discussionmentioning

confidence: 90%

“…Reductions in the thermal sensitivity of Hbs have been demonstrated in several vertebrate species, from active fishes (Rossi-Fanelli and Antonini, 1960) to ruminants (De Rosa et al, 2004), hummingbirds (Johansen et al, 1987) and even the woolly mammoth (Campbell et al, 2010). Though the specific mechanisms behind these reductions in the temperature dependence of O 2 binding affinity vary and indicate multiple evolutionary origins, their convergent physiological function protects O 2 delivery in these regionally heterothermic animals (Weber and Campbell, 2011).…”

Section: Introductionmentioning

confidence: 99%

High thermal sensitivity of blood enhances oxygen delivery in the high-flying bar-headed goose

Meir

Milsom

2013

Journal of Experimental Biology

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SUMMARYThe bar-headed goose (Anser indicus) crosses the Himalaya twice a year at altitudes where oxygen (O 2 ) levels are less than half those at sea level and temperatures are below −20°C. Although it has been known for over three decades that the major hemoglobin (Hb) component of bar-headed geese has an increased affinity for O 2 , enhancing O 2 uptake, the effects of temperature and interactions between temperature and pH on bar-headed goose Hb-O 2 affinity have not previously been determined. An increase in breathing of the hypoxic and extremely cold air experienced by a bar-headed goose at altitude (due to the enhanced hypoxic ventilatory response in this species) could result in both reduced temperature and reduced levels of CO 2 at the blood-gas interface in the lungs, enhancing O 2 loading. In addition, given the strenuous nature of flapping flight, particularly in thin air, blood leaving the exercising muscle should be warm and acidotic, facilitating O 2 unloading. To explore the possibility that features of blood biochemistry in this species could further enhance O 2 delivery, we determined the P 50 (the partial pressure of O 2 at which Hb is 50% saturated) of whole blood from bar-headed geese under conditions of varying temperature and [CO 2 ]. We found that blood-O 2 affinity was highly temperature sensitive in bar-headed geese compared with other birds and mammals. Based on our analysis, temperature and pH effects acting on blood-O 2 affinity (cold alkalotic lungs and warm acidotic muscle) could increase O 2 delivery by twofold during sustained flapping flight at high altitudes compared with what would be delivered by blood at constant temperature and pH.

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“…The mixing technique consisted of the volumetric mixing of 0% O 2 -saturated blood and 100% O 2 -saturated blood to achieve the desired S O2 at various points (i.e. 90, 70, 50, 40, 20, 10, 5% S O2 ) along the curve with subsequent measurement of the P O2 of the resulting mixture using an i-STAT blood gas analyzer (37°C; Abbott Point of Care, Princeton, NJ, USA) (Black and Tenney, 1980;Johansen et al, 1987;Nörgaard-Pedersen et al, 1972;Qvist et al, 1981). Use of the i-STAT analyzer also allowed verification of pH and P CO2 , and Tucker chamber analyses (Tucker, 1967) provided verification of blood O 2 content.…”

Section: O 2 -Hb Dissociation Curve Characterizationmentioning

confidence: 99%

High-affinity hemoglobin and blood oxygen saturation in diving emperor penguins

Meir

Ponganis

2009

Journal of Experimental Biology

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SUMMARYThe emperor penguin (Aptenodytes forsteri) thrives in the Antarctic underwater environment, diving to depths greater than 500 m and for durations longer than 23 min. To examine mechanisms underlying the exceptional diving ability of this species and further describe blood oxygen (O 2 ) transport and depletion while diving, we characterized the O 2 -hemoglobin (Hb) dissociation curve of the emperor penguin in whole blood. This allowed us to (1) investigate the biochemical adaptation of Hb in this species, and (2) address blood O 2 depletion during diving, by applying the dissociation curve to previously collected partial pressure of O 2 (P O2 ) profiles to estimate in vivo Hb saturation (S O2 ) changes during dives. This investigation revealed enhanced Hb-O 2 affinity (P 50 =28 mmHg, pH 7.5) in the emperor penguin, similar to high-altitude birds and other penguin species. This allows for increased O 2 at low blood P O2 levels during diving and more complete depletion of the respiratory O 2 store. S O2 profiles during diving demonstrated that arterial S O2 levels are maintained near 100% throughout much of the dive, not decreasing significantly until the final ascent phase. End-of-dive venous S O2 values were widely distributed and optimization of the venous blood O 2 store resulted from arterialization and near complete depletion of venous blood O 2 during longer dives. The estimated contribution of the blood O 2 store to diving metabolic rate was low and highly variable. This pattern is due, in part, to the influx of O 2 from the lungs into the blood during diving, and variable rates of tissue O 2 uptake.

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Respiratory Properties of Blood and Myoglobin in Hummingbirds

Cited by 46 publications

References 29 publications

Biomechanical, Respiratory and Cardiovascular Adaptations of Bats and the Case of the Small Community of Bats in Chile

Biomechanical, Respiratory and Cardiovascular Adaptations of Bats and the Case of the Small Community of Bats in Chile

High thermal sensitivity of blood enhances oxygen delivery in the high-flying bar-headed goose

High-affinity hemoglobin and blood oxygen saturation in diving emperor penguins

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