title: Blood bank conditions and RBCs: the progressive loss of metabolic modulation.
abstract: BACKGROUND
  Human RBC metabolism is modulated by the cell oxygenation state. Among other mechanisms, competition of deoxyhemoglobin and some glycolytic enzymes for the cytoplasmic domain of band 3 is probably involved in modulation. This metabolic modulation is connected to variations in intracellular NADPH and ATP levels as a function of the oxygenation state of the cell, and, consequently, it should have physiologic relevance. The present study investigates the effect of storage on this metabolic modulation and its relationship with the alteration of membrane protein composition.
  
  
  METHODS
  RBCs stored in CPD-saline-adenine-glucose-mannitol were assayed for glucose uptake and partition between glycolysis and the pentose phosphate pathway at high and low oxygen saturation by nuclear magnetic resonance spectroscopy after 1, 14, 21, 35, and 42 days of storage. Membrane protein composition was determined by SDS-PAGE on Days 1, 14, 35, and 42. Metabolic values and 2,3 DPG concentration were also measured after rejuvenation for 1 hour at 37 degrees C with pyruvate-inosine-phosphate-adenine solution on Day 21.
  
  
  RESULTS
  Metabolic differences between RBCs incubated at high and low oxygen saturation decreased during storage, and, on Day 35, the two groups did not have significant differences (p = 0.111). SDS-PAGE showed that membrane protein composition was concurrently modified. The percentage of unmodified band 3 decreased during storage, principally between Days 14 and 35. In rejuvenated RBCs, oxygen-dependent modulation was not restored.
  
  
  CONCLUSIONS
  RBCs stored in CPD-saline-adenine-glucose-mannitol do show a progressive loss of oxygen-dependent metabolic modulation, which is not restored after rejuvenation and which seems partly related to modifications in membrane proteins, mainly band 3.
authors.affiliation: Institute of Chemistry and Clinical Chemistry, Faculty of Medicine, Catholic University, Rome, Italy. i.messana@uniserv.ccr.rm.cnr.it
authors.forename: I
authors.initials: I
authors.lastname: Messana
authors.forename: L
authors.initials: L
authors.lastname: Ferroni
authors.forename: F
authors.initials: F
authors.lastname: Misiti
authors.forename: G
authors.initials: G
authors.lastname: Girelli
authors.forename: S
authors.initials: S
authors.lastname: Pupella
authors.forename: M
authors.initials: M
authors.lastname: Castagnola
authors.forename: B
authors.initials: B
authors.lastname: Zappacosta
authors.forename: B
authors.initials: B
authors.lastname: Giardina
mesh_terms: D000225:Adenine; D001771:Blood Banks; D001793:Blood Preservation; D002470:Cell Survival; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D005110:Extracellular Space / Q000737:chemistry; D005947:Glucose / Q000493:pharmacokinetics; D006801:Humans; D008353:Mannitol; D008565:Membrane Proteins / Q000302:isolation & purification; D010100:Oxygen / Q000494:pharmacology; D010427:Pentose Phosphate Pathway; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis; D012965:Sodium Chloride; D012967:Sodium Dodecyl Sulfate
chemical_list: C037839:ADSOL; D008565:Membrane Proteins; D012967:Sodium Dodecyl Sulfate; D008353:Mannitol; D012965:Sodium Chloride; D012964:Sodium; D005947:Glucose; D000225:Adenine; D011188:Potassium; D010100:Oxygen