title: (Thr-59)-insulin-like growth factor I stimulates 2-deoxyglucose transport in BC3H1 myocytes through the insulin-like growth factor receptor, not the insulin receptor.
abstract: The murine non-fusing muscle cell line contains distinct receptors for insulin and insulin-like growth factors. Pretreatment of myocytes with insulin for 20 h at 37 degrees C inhibits the binding of [125I]iodoinsulin by 60% without affecting the binding of [125I]iodoinsulin-like growth factor I. The ED50 values for down-regulation of the insulin and insulin-like growth factor receptor by their respective ligands are 1 nM and 3 nM, respectively. Insulin, (Thr-59)-insulin-like growth factor I and multiplication-stimulating activity stimulate 2-[3H]deoxyglucose transport in myocytes with ED50 values of 5 nM, 5.6 nM and 33 nM, respectively. In order to determine whether (Thr-59)-insulin-like growth factor I stimulates 2-[3H]deoxyglucose transport in myocytes via its own receptor or the insulin receptor, we determined the activity of these peptides after down-regulation of the insulin receptor. The rate of 2-[3H]deoxyglucose transport in myocytes pretreated with insulin (5 nM) is elevated but returns to control levels by 1 h after the washout of insulin. The dose-response curve for insulin-stimulated 2-[3H]deoxyglucose transport is shifted to the right (ED50 greater than 100 nM) immediately after insulin washout but is normal by 1 h after insulin washout. In contrast, the dose-response curve for (Thr-59)-insulin-like growth factor I is unchanged in insulin-pretreated cells immediately after insulin washout. These data show that (Thr-59)-insulin-like growth factor I stimulates 2-[3H]deoxyglucose transport in myocytes by acting through an insulin-like growth factor receptor and not through the insulin receptor. Since multiplication-stimulating activity is 6-fold less active than (Thr-59)-insulin-like growth factor, they both may be acting through a type 1 insulin-like growth factor receptor.
mesh_terms: D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D007328:Insulin / Q000031:analogs & derivatives / Q000378:metabolism; D007333:Insulin Resistance; D007334:Insulin-Like Growth Factor I / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology; D051379:Mice; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D011972:Receptor, Insulin / Q000187:drug effects / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D017451:Receptors, Somatomedin; D013002:Somatomedins; D013268:Stimulation, Chemical
chemical_list: D003837:Deoxy Sugars; D007328:Insulin; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D013002:Somatomedins; C008147:insulin, iodo-; D007334:Insulin-Like Growth Factor I; C048675:insulin-like growth factor I, Thr(59)-; D003847:Deoxyglucose; D011972:Receptor, Insulin