Hemopoietic effects of purified bacterially synthesized multi-CSF in normal and marrow-transplanted mice.

Normal adult mice and irradiated, marrow-transplanted mice were injected three times daily for 6 days with 200 ng purified bacterially synthesized recombinant Multi-CSF. Normal mice responded with increased peritoneal macrophages, eosinophils and neutrophils, spleen weight increases and major increases in spleen mast cells and hemopoietic progenitor cells. Irradiated, marrow-transplanted mice failed to develop large increases in peritoneal cell numbers but did show rises in spleen weight, marrow cellularity and spleen and marrow progenitor cell levels. The results confirm data indicating a regulatory role for Multi-CSF in vivo and suggest that Multi-CSF may be of some value in accelerating hemopoietic regeneration following marrow transplantation.