Comparative NMR studies of diffusional water permeability of red blood cells from different species: XVIII platypus (Ornithorhynchus anatinus) and saltwater crocodile (Crocodylus porosus).
Cell Biol Int
; 34(7): 703-8, 2010 Jul.
Article
em En
| MEDLINE
| ID: mdl-20187871
ABSTRACT
As part of a programme of comparative measurements of Pd (diffusional water permeability) the RBCs (red blood cells) from an aquatic monotreme, platypus (Ornithorhynchus anatinus), and an aquatic reptile, saltwater crocodile (Crocodylus porosus) were studied. The mean diameter of platypus RBCs was estimated by light microscopy and found to be approximately 6.3 microm. Pd was measured by using an Mn2+-doping 1H NMR (nuclear magnetic resonance) technique. The Pd (cm/s) values were relatively low approximately 2.1 x 10(-3) at 25 degrees C, 2.5 x 10(-3) at 30 degrees C, 3.4 x 10(-3) at 37 degrees C and 4.5 at 42 degrees C for the platypus RBCs and approximately 2.8 x 10(-3) at 25 degrees C, 3.2 x 10(-3) at 30 degrees C, 4.5 x 10(-3) at 37 degrees C and 5.7 x 10(-3) at 42 degrees C for the crocodile RBCs. In parallel with the low water permeability, the Ea,d (activation energy of water diffusion) was relatively high, approximately 35 kJ/mol. These results suggest that "conventional" WCPs (water channel proteins), or AQPs (aquaporins), are probably absent from the plasma membranes of RBCs from both the platypus and the saltwater crocodile.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ornitorrinco
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Água
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Espectroscopia de Ressonância Magnética
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Permeabilidade da Membrana Celular
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Jacarés e Crocodilos
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Membrana Eritrocítica
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Eritrócitos
Limite:
Animals
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Humans
Idioma:
En
Revista:
Cell Biol Int
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Romênia