Comparative studies of the respiratory functions of mammalian blood. VII Armadillo (Dasypus novemcinctus)
1971; Elsevier BV; Volume: 13; Issue: 2 Linguagem: Inglês
10.1016/0034-5687(71)90090-9
ISSN1872-7611
AutoresDharam S. Dhindsa, A. S. Hoversland, James Metcalfe,
Tópico(s)High Altitude and Hypoxia
ResumoThe respiratory characteristics of blood from 4 nine-banded armadillos (Dasypus novemcinctus) were studied. One animal was anemic when studied initially (blood oxygen capacity 9.5 vol %); with treatment its blood oxygen capacity rose and the average blood oxygen capacity for all four animals (excluding the observations during anemia) was 14.8 ± 1.6 vol%. Oxygen dissociation curves for whole blood were constructed at 36°C and were corrected to a plasma pH of 7.40. The mean blood P50 for the animals without anemia was 23.3 ± 1.1 mm Hg. The blood P50 of the anemic armadillo (26.5 ± 0.9 mm Hg) was significantly higher (P < 0.01). The concentration of 2,3-diphosphoglycerate was higher in the blood of the anemic animal (4.33 μM/ml red cells) than in the others (2.83 μM/ml red cells). The Bohr factor (Δlog PO2/ΔpH) was −0.55 ± 0.06. In animals without anemia the red cell count averaged 5.26 million/mm3 and the hematocrit averaged 31%. Armadillo hemoglobin migrates as two bands. The major component migrates at the same rate as human A hemoglobin on starch gel electrophoresis at pH 8.6. Like other burrowing animals, the armadillo has blood with a higher affinity for oxygen than would be predicted for its size. This, and its low rate of oxygen consumption per kilogram, may be considered as adaptations to environmental hypoxia.
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