Tissue localization and fate in mice of injected multipotential colony-stimulating factor

Abstract

The hemopoietic regulator multipotential colony-stimulating factor [Multi-CSF (interleukin 3)] has proliferative effects on a wide range of hemopoietic cells in vitro and in vivo. Native or recombinant Multi-CSF injected intravenously into adult mice had an initial half-life of 3-5 min and a second phase of 50 min. Clear labeling of hemopoietic cells was observed in the bone marrow and spleen of mice injected intravenously with recombinant 125I-labeled Multi-CSF showing that injected Multi-CSF can obtain access to such cells in situ. A high proportion of injected 125I-labeled Multi-CSF of both types became localized in the liver and in the kidney (in cells of the Bowman's capsule and proxima..