Osmotic and diffusive properties of intracellular water in camel erythrocytes: effect of hemoglobin crowdedness.
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 (approximately 65 vs approximately 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 approximately 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.
Bogner
Peter
P
Institute of Diagnostic Imaging and Radiation Oncology, University of Kaposvár, 7400 Kaposvár, Guba S.u. 40, Hungary. peter.bogner@aok.pte.hu
Miseta
Attila
A
Berente
Zoltan
Z
Schwarcz
Attila
A
Kotek
Gyula
G
Repa
Imre
I
D000818:Animals; D001692:Biological Transport; D001834:Body Water / Q000378:metabolism*; D002162:Camelus / Q000097:blood*; D004058:Diffusion; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D009994:Osmolar Concentration; D009995:Osmosis; D012965:Sodium Chloride / Q000494:pharmacology; D013045:Species Specificity
D006454:Hemoglobins; D012965:Sodium Chloride