Dissociation curve of bird blood and effect of red cell oxygen consumption
1973; Elsevier BV; Volume: 17; Issue: 3 Linguagem: Inglês
10.1016/0034-5687(73)90001-7
ISSN1872-7611
AutoresPeter L. Lutz, I. S. Longmuir, Julia Tuttle, Knut Schmidt‐Nielsen,
Tópico(s)Hemoglobin structure and function
ResumoIn contrast to previously reported findings, pigeon blood was found to have oxygen dissociation curves similar in shape and position to those of mammals. At pH =7.5, pco2 = 35 mm Hg, and temperature = 41°C, the oxygen half saturation pressure (P50) was 29.46 mm Hg. This finding conflicts with the common belief that bird blood in general has a low affinity for oxygen. Erroneous results can be due to the high rate of oxygen consumption of bird blood (1.04× 10−3 ml O2 · min−1 · ml−1 for pigeon blood at 41°C), so that a time lapse between gas equilibration and analysis will result in an erroneous low oxygen content and consequently an assignment of the dissociation curve to the right. In our method, the measurements take place directly in the equilibration chamber, so that there is no time lag between sampling and analysis. The Bohr effect factor (Δlog P50/ΔpH) was −0.566, similar to that of a mammal of the same body size. The effects of hemolysis and of altering PCO2 and temperature are reported.
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