Proliferation of Hemopoietic Colony-Forming Cells Transplanted into Irradiated Mice

Abstract

The kinetics of proliferation of spleen colony-forming cells derived from transplanted marrow cells were studied by 2 different methods. Results indicate that transplanted colony-forming cells did not proliferate in heavily irradiated recipient mice during the first day after transplantation. After this initial lag phase, they increased in an exponential fashion for at least the next 7 days, with a doubling time of 20 to 25 hours. A transient decrease in radiation sensitivity of transplanted cells derived from marrow was observed during the posttransplantation lag phase. This increase was maximal approximately one day after transplantation.