Studies in red blood cell preservation: 9. The role of glutamine in red cell preservation.

Previous studies have demonstrated that an additive solution containing ammonium chloride (NH4+) and phosphate (Pi) in addition to adenine, glucose and mannitol would support red blood cell (RBC) in vitro characteristics and in vivo 24-hour viability after storage for 9 weeks. The purpose of the present study was to determine if NH4+ generated by the action of glutaminase on glutamine could be substituted for added NH4+ salts. Packed RBCs were stored with equal volumes of adenine, glucose, mannitol, and citrate containing additive solutions with 10 mM glutamine (EAS 31) or with 10 mM glutamine and either 10 (EAS 36) or 20 mM (EAS 37) Pi. One aliquot was stored with Adsol. The mean ATP levels of the RBCs stored in the glutamine plus phosphate EASs were 132 (10 mM Pi) and 144% (20 mM Pi) of the initial levels at 28 days, and at 84 days remained at 48 and 56%, respectively. The ATP levels of the RBC stored in Adsol were 105 and 25% at 28 and 84 days of storage, respectively. Percentage hemolysis and vesiculation was significantly lower (p < 0.01) for RBCs stored in glutamine and glutamine plus phosphate as compared to RBCs stored in Adsol. The levels of NH4+ were 22 to 34% higher in the EASs than in Adsol at the end of 84 days of storage, suggesting that glutamine is broken down by glutaminase to generate NH4+. The mean corpuscular volumes (MCVs) of RBCs in EASs 36 and 37 were substantially higher than in Adsol throughout the course of storage (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)