title: The modulation of growth of normal rat liver epithelial cells in calcium-poor medium by epidermal growth factor, phenobarbital, phorbol ester, and retinoic acid.
abstract: The ability of a normal rat liver epithelial cell line with phenotypic characteristics of "oval" cells to grow in calcium-poor medium has been investigated. The growth of these cells could be arrested in medium containing 0.03 mM Ca2+, a concentration below which cell necrosis began to occur 24 h postexposure. With increasing calcium concentration, progressive cell proliferation was observed. Epithelial growth factor (EGF) (10 ng/ml) increased the survival and proliferation of cells in calcium-poor medium and the response was inversely correlated with the extracellular calcium concentration. In contrast, phenobarbital (0.2 to 2 mM), 12-O-tetradecanoylphorbol-13-acetate (0.01 to 1 microgram/ml), or retinoic acid (0.001 to 0.1 microgram/ml) depressed growth of cells in calcium-poor medium. The results confirm the ability of EGF to lower the calcium requirement for proliferation of normal cells, but such an effect does not seem to be a universal property of tumor promoters.
mesh_terms: D000818:Animals; D002118:Calcium; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D008099:Liver / Q000166:cytology* / Q000187:drug effects; D010634:Phenobarbital / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D010704:Phorbols; D014212:Tretinoin; D004815:Epidermal Growth Factor; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D010634:Phenobarbital