title: In vitro production of lymphocyte and granulocyte proliferation inhibitors (chalones?) from living cells.
abstract: Media conditioned with viable rat and calf spleen lymphocytes were seen to be able to inhibit 3H-thymidine uptake by rat thymocytes and the mitogenic response of human lymphocytes to PHA but not bone marrow cells proliferation. The inhibitor appeared to have a molecular weight greater than 50,000 daltons, as determined by Amicon Diaflo ultrafiltration. Media conditioned with rat granulocytes had a similar tissue specific but species non-specific inhibitory action. Also human leukemic cells appeared able to produce in vitro an inhibitor of cell proliferation when a certain degree of differentiation was present.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002417:Cattle; D002478:Cells, Cultured; D003470:Culture Media; D006131:Growth Inhibitors / Q000096:biosynthesis* / Q000302:isolation & purification; D006801:Humans; D007938:Leukemia / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism*; D008938:Mitosis; D008970:Molecular Weight; D051381:Rats; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology; D014462:Ultrafiltration
chemical_list: D003470:Culture Media; D006131:Growth Inhibitors