An Erythrocyte Defect in Splenectomized X‐Irradiated Mice Restored with Spleen Colony Cells

Abstract

Summary The profound anaemia previously seen in splenectomized irradiated LAF1 mice injected with isogenic spleen nodule cells, has been confirmed in two other mouse strains. The anaemia does not invariably cause death, but a slow recovery to normal haematocrit levels occurs in about 80 days.By splenectomy at various times after irradiation, some modification of the severity of the anaemia was achieved, but recovery was not accelerated.Implantation of normal splenic tissues in Millipore filter chambers intraperitoneally failed to modify the severity of the anaemia, but an improvement in the rate of recovery was observed. 59Fe 5‐hour uptake data indicate that spleen nodule cells do not help in the re‐population of erythroid elements of bone marrow, though there is some acceleration of re‐population of spleen as a result of injection of these cells. Both bone marrow cells and normal spleen cells are seen to be more effective than spleen nodule cells in the re‐populating bone marrow.Spontaneous recovery of the bone marrow erythroid population occurs in mice irradiated and injected with spleen nodule cells but an anaemia persists unless the spleen is present.It is concluded that an erythrocyte defect occurs in splenectomized, irradiated, spleen nodule cell‐injected mice — a defect which only slowly recovers.