Effect of insulin on the hepatic production of insulin-like growth factor-binding protein-1 (IGFBP-1), IGFBP-3, and IGF-I in insulin-dependent diabetes

摘要: Insulin-like growth factors (IGFs) circulate attached to binding proteins (IGFBPs). Only the unbound form of IGF is suggested be biological active. The main source circulating IGF-I and IGFBP-1 considered liver, but that IGFBP-3 not known. are GH dependent, whereas insulin regulated. aim present study was examine effect on hepatic secretion IGFBP-1, IGFBP-3, IGF-I. Seven insulin-dependent diabetic patients in whom withheld for 12 h were studied overnight fasted state. Blood sampled simultaneously from vein, a peripheral an artery before during infusion 3 h. basal levels vein several-fold elevated (249 +/- 44 micrograms/L) compared those healthy subjects (37 2 micrograms/L). Fasting concentrations inversely correlated (r = -0.918; P < 0.001). mean concentration (175 17 micrograms/L; -1.62 0.38 SD score) decreased with age-matched subjects. (4.50 0.33 mg/L) within normal range. There significant correlation between fasting 0.928; Basal splanchnic production 18 7 micrograms/min, no net exchanges or observed across area. Insulin inhibited 120 min glucose output 20 min. Serum IGF-I, increased significantly infusion. In summary, this demonstrates existence considerable liver insulinopenia complete blocking increases serum by despite levels. Thus, may play role determining bioavailability