title: Release of somatomedin-like activity by cultured WI-38 human fibroblasts.
abstract: Confluent cultures of normal diploid WI-38 human embryonic lung fibroblasts released somatomedin (SM)-like activity into their incubation medium during culture in serum-free medium. This postculture medium (conditioned medium) stimulated cell division in these same cultured WI-38 fibroblasts and 35SO4 uptake by hypophysectomized rat cartilage in vitro. The conditioned medium also contained immunoreactive SM (IRSM) activity which yielded parallel dose-response curves to human serum in a RIA for SM. The IRSM activity measured in conditioned medium was not the artifactual result of effects of possible SM-binding proteins or proteolytic enzymes in conditioned medium. These studies suggest that cultured WI-38 fibroblasts produce and release SM-like activity which has SM-like biological activity and is immunoreactive with a basic SM purified from human plasma Cohn fraction and having similarity with SM-C and insulin-like growth factor-I. Human GH appears to stimulate production and release of IRSM activity by these cells.
mesh_terms: D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D001681:Biological Assay; D002356:Cartilage / Q000187:drug effects; D002460:Cell Line; D004622:Embryo, Mammalian; D006801:Humans; D008168:Lung; D008934:Mitogens; D008970:Molecular Weight; D010447:Peptide Hydrolases; D011863:Radioimmunoassay; D051381:Rats; D013002:Somatomedins / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D008934:Mitogens; D013002:Somatomedins; D007611:Aprotinin; D010447:Peptide Hydrolases