Cell age-related monovalent cations content and density changes in stored human erythrocytes.
Conversion of erythrocyte membrane protein 4.1b to 4.1a occurs through a non-enzymatic deamidation reaction in most mammalian erythrocytes, with an in vivo half-life of approximately 41 days, making the 4.1a/4.1b ratio a useful index of red cell age [Inaba and Maede, Biochim. Biophys. Acta 944 (1988) 256-264]. Normal human erythrocytes distribute into subpopulations of increasing cell density and cell age when centrifuged in polyarabinogalactan density gradients. We have observed that, when erythrocytes were stored at 4 degrees C under standard blood bank conditions, the deamidation was virtually undetectable, as cells maintained the 4.1a/4.1b ratio they displayed at the onset of storage. By measuring the 4.1a/4.1b values in subpopulations of cells of different density at various time points during storage, a modification of the normal 'cell age/cell density' relationship was observed, as erythrocytes were affected by changes in cell volume in an age-dependent manner. This may stem from a different impact of storage on the imbalance of monovalent cations, Na(+) and K(+), in young and old erythrocytes, related to their different complement of cation transporters.
Minetti
G
G
Dipartimento di Biochimica, Sezione di Scienze, Università di Pavia, Italy. minetti@unipv.it
Ciana
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Profumo
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Zappa
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Vercellati
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Zanella
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Arduini
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Brovelli
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D001771:Blood Banks; D002414:Cations, Monovalent / Q000032:analysis*; D002469:Cell Separation; D048429:Cell Size; D004905:Erythrocyte Aging; D004910:Erythrocyte Membrane / Q000737:chemistry; D004912:Erythrocytes / Q000737:chemistry* / Q000145:classification; D006801:Humans; D007773:Lactates / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D013997:Time Factors; D014021:Tissue Preservation
D002414:Cations, Monovalent; D007773:Lactates; D008565:Membrane Proteins