title: Production of a colony-inhibitory factor by ethylamine in continuous, long-term marrow culture.
abstract: The effect of ethylamine (EA), a simple alkylamine, on continuous, long-term marrow culture was studied in the mouse. EA reduced the granulocyte-monocyte progenitor cell (CFU-c) activity in the supernatant of these cultures in a dose-dependent fashion. This inhibitory effect persisted even after the EA was completely removed from the culture. Moreover, the cell-free supernatant showed inhibitory activity on the growth of CFU-c using freshly isolated target cell. This inhibitory effect also persisted after the EA was completely removed from the culture. Thus, EA appeared to induce changes in these cultures not only by interfering with their potential to maintain the CFU-c but also by releasing a factor in the supernatant that was inhibitory to the CFU-c growth derived from fresh bone marrow. Electron microscopy indicated profound alterations in lysosomal structures. The selective accumulation of this weakly basic substance in the lysosomes may lead to elaboration and release of a colony-inhibitory factor in the supernatant. This effect of EA appears to be independent of its effect on receptor-mediated endocytosis.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects*; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003034:Coated Pits, Cell-Membrane / Q000648:ultrastructure; D003114:Colony-Forming Units Assay; D004305:Dose-Response Relationship, Drug; D005021:Ethylamines / Q000494:pharmacology*; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008074:Lipoproteins / Q000378:metabolism*; D008247:Lysosomes / Q000648:ultrastructure; D051379:Mice; D008811:Mice, Inbred DBA; D009000:Monocytes / Q000166:cytology; D011506:Proteins
chemical_list: D005021:Ethylamines; D008074:Lipoproteins; D011506:Proteins; C016313:colony inhibiting factor