ISSN:
1432-2013
Keywords:
Carbon Dioxide
;
Diffusion
;
Hemoglobin
;
Erythrocytes
;
Membrane Permeability
;
Kohlendioxid
;
Diffusion
;
Hämoglobin
;
Erythrocyten
;
Membranpermeabilität
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The CO2 diffusion constant (Krogh's diffusion constant) has been estimated from the CO2 flux across layers with defined thickness under steady state conditions. At 22°C and in hemoglobin solutions with a concentration of 33 g% the diffusion constant for CO2 was found to be 3.3×10−4 cm2 min−1 atm−1. This value is about 40% of the diffusion constant for CO2 in water. The relationship between the diffusion constant and the hemoglobin concentration was approximately linear in a concentration range of 10–40 g%. The temperature coefficient of the diffusion constant was −0.5%/°C both in water and hemoglobin solutions. At 38°C and in a hemoglobin solution with a concentration of 33 g%, the diffusion constant for CO2 was therefore 3.0×10−4 cm2 min−1 atm−1, the diffusion coefficient 11×10−6 cm2 s−1. A general theory for the diffusion of CO2 in hemoglobin solutions has been derived. According to this theory the diminution of the CO2 diffusion in hemoglobin solutions in comparison to water can be explained quantitatively by a reduction of the water space by the hemoglobin molecules. The diffusion constant for CO2 in layers of erythrocytes was insignificantly (0–3%) smaller than in hemoglobin solutions with the same hemoglobin concentration. It is concluded that the erythrocyte membrane does not offer a considerable resistance for the CO2 diffusion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00586422
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