Senescent erythrocytes: isolation of in vivo aged cells and their biochemical characteristics.

Rabbit erythrocytes were covalently labeled with biotin and then infused into the donor animal. Up to 60 days after infusion, the biotinylated cells were selectively isolated by their affinity for avidin. These aged erythrocytes, which are within 10 days of death, were analyzed for several biochemical parameters. The 2,3-bisphosphoglycerate and glutathione levels of these cells were constant with age; however, the adenosine 5'-triphosphate concentrations increased approximately 75% as the cells approached the end of their life span. The activities of several glycolytic enzymes did not change with age.