title: Growth hormone dependent stimulation of osteoblast-like cells in serum-free cultures via local synthesis of insulin-like growth factor I.
abstract: Gene-recombinant human growth hormone (rhGH) elicited a dose-dependent stimulation of the proliferation of osteoblast-like cells (OB), when grown in strictly serum-free longterm cultures. A half-maximal effect was observed at concentrations of 15-20 ng/ml and the maximal stimulation was 160% of hormone-free controls. The rhGH-induced effect on proliferation could be inhibited dose-dependently by the addition of an insulin-like growth factor (IGF) I-antiserum to the medium. Moreover, IGF I and rhGH had additive effects only when the exogenous IGF I concentration exceeded that of endogenously produced IGF I by a large margin. Thus, direct stimulation of OB proliferation by rhGH is, at least in part, mediated by IGF I-like immunoreactivity.
authors.affiliation: Department of Medicine, University Hospital of Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Ernst
authors.forename: E R
authors.initials: ER
authors.lastname: Froesch
mesh_terms: D000818:Animals; D001846:Bone Development / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000276:immunology / Q000494:pharmacology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013002:Somatomedins / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D003094:Collagen