Erythropoietic Recovery Measured by Fe59 Uptake in Irradiated Mice Protected with Bone Marrow.

Abstract

The lethal effects of whole body irradiation of mice and other mammals is offset by intravenous grafting of nonirradiated bone marrow which may be isologous, homologous, or heterologous. Survival of animal after lethal doses of radiation depends largely on time of hemopoietic recovery. This has been measured in mice by recovery of the count of circulating lymphocytes and granulocytes and by recovery of hemoglobin concentration and platelet count. Recovery of hemoglobin concentration is not a satisfactory index of recovery because it is obscured by the slow downward trend of circulating survivor cells over a period of 12 to 16 days after radiation. Odell and Caldwell found donor type erythrocytes in irradiated rats in significant numbers only after 14 to 20 days. To examine quickly the recovery of erythropoiesis we have used the Fe59 uptake method and find that recovery begins after the third day post-radiation and is discernible by the sixth day when isologous cells are administered. Moreover, the responses elicited by homologous and heterologous cells are measurably different from one another and from the isologous case by the sixth day. The method appears to distinguish the 3 genetically different cell types by the induced Fe59 uptake.