EFFECTS OF LOST SURFACE-AREA ON RED-BLOOD-CELLS AND RED-BLOOD-CELL SURVIVAL IN MICE

The effects of removing area from mouse red blood cells on the fate of the cells after reinfusion were investigated. When cells were made ne arly spherical (by reducing cell area by similar to 35%) and then rein fused into the animal, most were cleared from the circulation within 1 -2 h, although similar to 20% of the cells survived for 4 h or longer. When only 20% of the area was removed (leaving a 15% excess), more th an 90% of the cells continued to circulate for 4 h. After reinfusion, the mean surface area of the surviving cells remained constant (73-75 mu m(2)), but the mean volume decreased, from 56.6 +/- 2.1 to 49.1 +/- 1.5 mu m(3) (+/-SD of 5 replicates) over 4 h. These changes did not o ccur in cells suspended in plasma but not reinfused into the animal. T hus a loss of surface area results in a decrease in cell volume, as if to maintain a requisite degree of deformability. The results support the hypothesis that the increase in cell density associated with incre asing cell age may be a consequence of surface area loss.