PRODUCTION OF STEM-CELL PROLIFERATION STIMULATORS AND INHIBITORS BY HEMATOPOIETIC CELL-SUSPENSIONS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 28  (3) , 156-160
Abstract
In mice treated with phenylhydrazine hemopoietic spleen colony forming cells (CFU-S) proliferate rapidly in the bone marrow but not in the spleen. Using such mice, the production of factors responsible for the control of CFU-S proliferation was studied. When irradiated spleen cells were incubated with non-irradiated bone marrow cells, there was a marked fall in the proportion of femoral CFU-S in DNA synthesis. In the converse experiments, rapid triggering of splenic CFU-S was achieved. These effects can be eliminated by washing the irradiated cells prior to incubation. They were retained in the supernatant media conditioned by these cells. When the washed cells were incubated in fresh medium at 37.degree. C, stimulatory and inhibitory activities reappeared but after different incubation periods. Proliferation stimulatory and inhibitory factors acting on CFU-S can apparently be produced by the same hemopoietic cell suspension.