Physical Characteristics of Red Cells Collected from the Spleen

Abstract

Kinetics of cell washout, when isolated cat spleens are perfused with Ringer solution, have shown previously that the red cells stored in the spleen correspond to a system of three compartments (fast, intermediate, and slow); morphological studies, at different stages of the washout, have already identified these compartments as free cells in vascular channels, free cells within sinuses, and cells adhering to sinus walls, respectively. By collecting the venous outflow at three particular stages of the washout fairly pure samples (>85%) of the cells from each compartment have now been obtained. We have measured the density (phthalate method), volume, and osmotic changes (Celloscope) of these cells. Cells from the fast and intermediate compartments were not significantly different from those of arterial blood, but cells from the slow compartment were lighter (specific gravity difference was 0.0064; p < 0.01), larger in volume (5.0%; p < 0.01), and swelled 14% less in 200 mOsmol/l (p < 0.01). These differences indicated that cells from the slow compartment might be predominantly younger cells and this has been confirmed by finding reticulocyte counts of 58.0 ± 3.8 (S.E.) %. It is suggested that immature red cells, released from the bone marrow, may be sequestered in the spleen and matured.