title: Factors affecting the proliferation and differentiation of clonogenic hematopoietic stem cells in vitro.
abstract: The characteristics of hematopoietic factors modulating the growth of clonogenic pluripotent stem cells (PSC) in culture (i.e., CFU-GEMM) are examined. The chemical and biologic properties of "burst-promoting activity" (BPA) are compared with those of the lymphokine interleukin-3 (Il-3). The preponderance of the data available suggests that the active moiety of each of these growth factors may be chemically identical since both BPA and purified Il-3 are capable of supporting the growth of PSC in vitro. The effects of hemin on the growth of CFU-GEMM are also examined experimentally. The results show conclusively that, in the absence of exogenous (BPA), hemin is also capable of supporting the growth of CFU-GEMM in culture and to a level that is consistently higher than that of BPA alone. It is therefore suggested that hemin is capable of augmenting the growth of GEMM colonies in vitro in conjunction with BPA/Il-3. However, the in situ role of each of these "candidate" regulators of hemopoiesis remains largely unknown.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002999:Clone Cells; D005260:Female; D006133:Growth Substances / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006418:Heme / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D007377:Interleukin-3; D008222:Lymphokines / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000166:cytology
chemical_list: D006133:Growth Substances; D007377:Interleukin-3; D008222:Lymphokines; D006418:Heme