Population sizes of granulocyte-macrophage and monocyte-macrophage colony-forming cells in Sl/Sld.

The sizes of granulocyte-macrophage (CFU-c) and monocyte-macrophage (CFC) progenitor cell populations were measured and compared in Sl/Sld and +/+ mice. In the marrow, the CFU-c and CFC population sizes were 40% and 67%, respectively, of the +/+ marrow CFU-c and CFC population sizes. There was no difference in the size of these two-cell populations in the spleens or thymi of Sl/Sld mice as compared with +/+ mice. Furthermore, the marrow CFC population was found to be heterogeneous by velocity sedimentation. One of the marrow CFC subpopulations is characterized by a velocity sedimentation value of 5.05 mm/h while the other has a value of 6.30 mm/h.