title: The isolation and activity of growth-stimulating factors from human platelets.
abstract: Optimal conditions for determining the mitogenic activity of platelet growth factor in a homologous system (human palmar fascia fibroblasts/human platelet growth factor) were established. With the aid of this system it was possible to test the active fraction from crude platelet extract following affinity chromatography on heparin-Sepharose, chromatofocusing and molecular sieve filtration. This fraction has an isoelectric point of pH greater than 9 with a molecular mass of about 12000 daltons and reacts with beta-thromboglobulin antiserum. The addition of protease inhibitors proved essential for the isolation of the active growth factor, in order to prevent proteolytic degradation to a biologically inactive substance that is immunologically identical to beta-thromboglobulin. In addition to stimulation of DNA synthesis, the isolated growth factor induces enhanced synthesis of collagen and glycosaminoglycans in fibroblasts in vitro.
mesh_terms: D002452:Cell Count; D002455:Cell Division; D003094:Collagen / Q000096:biosynthesis; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D007525:Isoelectric Focusing; D010447:Peptide Hydrolases; D010982:Platelet-Derived Growth Factor / Q000302:isolation & purification / Q000494:pharmacology*; D011392:Proline / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D001620:beta-Thromboglobulin / Q000032:analysis
chemical_list: D006025:Glycosaminoglycans; D010982:Platelet-Derived Growth Factor; D013431:Sulfates; D001620:beta-Thromboglobulin; D003094:Collagen; D011392:Proline; D010447:Peptide Hydrolases; D006909:Hydroxyproline