Production of carrier proteins for insulin-like growth factors (IGFs) by rat osteoblastic cells. Regulation by IGF I and cortisol.
A bone-derived rat cell line, PyMS, releases IGF I and IGF carrier proteins which are similar to those found in rat serum. Western blot analysis of culture media conditioned by hormone-treated cells shows that growth hormone and IGF I stimulate and cortisol inhibits production of IGF carrier proteins in vitro. A glycosylated carrier protein species of 49-42 kDa is closely related to the subunits of the growth hormone-dependent carrier protein complex found in rat serum. In addition, rhIGF I rapidly induces a 32 kDa, non-glycosylated IGF-binding protein whose accumulation is markedly increased by cortisol.
Schmid
C
C
Metabolic Unit, CL, University Hospital, Zurich, Switzerland.
Zapf
J
J
Froesch
E R
ER
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D006854:Hydrocortisone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D011347:Procollagen / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000096:biosynthesis* / Q000494:pharmacology*
D011347:Procollagen; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D000469:Alkaline Phosphatase; D006854:Hydrocortisone