Brought to you by Portland Press Ltd.
Published on behalf of the International Federation for Cell Biology
Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (2005) 29, 731–736 (Printed in Great Britain)
Osmotic and diffusive properties of intracellular water in camel erythrocytes: Effect of hemoglobin crowdedness
Peter Bognera*, Attila Misetab, Zoltan Berentec, Attila Schwarczd, Gyula Koteka and Imre Repaa
aInstitute of Diagnostic Imaging and Radiation Oncology, University of Kaposvár, 7400 Kaposvár, Guba S.u. 40, Hungary
bDepartment of Clinical Chemistry, University of Pécs, Faculty of Medicine, Hungary
cDepartment of Biochemistry and Medical Chemistry, University of Pécs, Faculty of Medicine, Hungary
dDepartment of Neurosurgery, University of Pécs, Faculty of Medicine, Hungary


Abstract

Camel erythrocytes have exceptional osmotic resistance and is believed to be due to augmented water-binding associated with the high hydrophilicity of camel hemoglobin. In practical terms this means that the proportion of osmotically non-removable water in camel erythrocytes is nearly 3-fold greater than that in human erythrocytes (&007E;65 vs &007E;20%). The relationship between water diffusion and the osmotic characteristics of intracellular water is the subject of this report.

The amount of osmotically inactive water is 2-fold greater in camel hemoglobin solution in vitro compared to that of human, but water diffusion does not differ in camel and human hemoglobin solutions. However, the evaluation of water diffusion by magnetic resonance measurements in camel erythrocytes revealed &007E;15% lower apparent diffusion coefficient (ADC) compared with human erythrocytes. When human erythrocytes were dehydrated to the level of camel erythrocytes, their osmotic and water diffusion properties were similar. These results show that a lower ADC is associated with a more pronounced increase in osmotically inactive water fraction. It is proposed that increased hemoglobin hydrophilicity allows not only augmented water-binding, but also a closer hemoglobin packaging in vivo, which in turn is associated with slower ADC and increased osmotic resistance.


Key words: Diffusion, Hydration water, Hemoglobin, Osmotic.

*Corresponding author. Tel.: +36 30 9949 907; fax: +36 82 502 020.


Received 17 April 2005/18 April 2005; accepted 18 April 2005

doi:10.1016/j.cellbi.2005.04.008


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)