Aged erythrocytes exhibit decreased anion exchange

The rate of transport of [ 32 P] phosphate into human and bovine erythrocytes and of a spin-label analogue of phosphate (Tempo-phosphate) into human erythrocytes was found to decrease with increasing erythrocyte age by 15–20% when comparing 20% most dense cells with 20% of lightest cells. The activation energy of Tempo-phosphate transport did not show significant changes upon erythrocyte aging.