| Abstract: | Colony formation and growth in vitro by C57B1 mouse bone marrow cells were analysed following stimulation by a standard dose of serum colony stimulating factor. Under restricted conditions, colony crowding was observed to potentiate colony growth rates. The addition of thymic or lymph node lymphoid cells or nonviable bone marrow cells also potentiated colony growth. Extensive reutilisation of nuclear material by bone marrow colony cells was observed when labeled lymphoid and bone marrow cells were added to the culture system. The results provide evidence that lymphocytes can exert trephocytic effects on proliferating hematopoietic cells. |
