Regeneration of phosphorylated metabolites in stored erythrocytes in an open perfusion system: studies using ³¹P NMR spectroscopy

Summary. Human erythrocytes were maintained at high haematocrit in a metabolically functional state for several hours in a thermodynamically open perfusion apparatus. The concentrations of ATP and 2,3‐bisphosphoglycerate (2,3‐DPG) and pH were continuously monitored before and after metabolic perturbations by using ³¹P NMR; the monitoring was achieved with a ³¹P flow‐through probe. Methylphosphonate was added to plasma perfusion medium as a phosphorus concentration standard and as a ³¹P NMR pH probe molecule. The rates of decline of ATP and 2,3‐DPG levels in fresh cells in a glucose‐free medium were measured as were the rates of reformation in response to a ‘rejuvenation’ medium. Also, rates of ATP and 2,3‐DPG synthesis during perfusion with Krebs bicarbonate–0·5 mmol/l glucose and perfusion with pooled plasma were measured in cells that had been previously stored at 4°C for 5 weeks.