Temperature insensitive O2 in blood of the tree frogChiromantis petersi
Date
1980Author
Johansen, Kjell
Lykkeboe, Gunnar
Kornerup, Sonja
Maloiy, GMO
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Respiratory gas exchange and blood respiratory properties have been studied in the East-African tree frogChiromantis petersi. This frog is unusually xerophilous, occupies dry habitats and prefers body temperatures near 40°C and direct solar exposure. Total O2 uptake was low at 81 μl O2·g−1·h−1±19.0 (SD) at 25°C increasing to 253.5 μl O2·g−1·h−1±94.8 (SD) at 40°C giving aQ 10 value of 2.1. Skin O2 uptake at 25°C was 38.5% of total. The gas exchange ratio was 0.71 for whole body gas exchange, 0.61 for the lungs and 1.02 for the skin at 25°C.
Blood O2 affinity was low with aP 50 of 47.5 mmHg at 25°C and pH 7.65. Then H-value at 25°C increased from 2.7 aroundP 50 to 5.0 at O2 saturations exceeding 70–80%. Surprisingly, blood O2 affinity was nearly insensitive to temperature expressed by a ΔH value of ±1.0 kcal·mole between 25 and 40°C.
The adaptive significance of the low O2 affinity, the increase ofn H with O2 saturation and the temperature insensitive O2-Hb binding is discussed in relation to the high and fluctuating body temperatures ofChiromantis
URI
http://link.springer.com/article/10.1007/BF00688625http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/51054
Citation
Journal of comparative physiology 1980, Volume 136, Issue 1, pp 71-76Publisher
Springer-Verlag Department of Zoophysiology, University of Aarhus, DK-8000, Aarhus C., Denmark Comparative Animal Physiology Research Unit, University of Nairobi,