Nutritional regulation of the growth hormone and insulin-like growth factor-binding proteins.
Both growth hormone (GH) and insulin-like growth factors (IGFs) associate with specific binding proteins. Besides control by hormones, these binding proteins are nutritionally regulated. The GH-binding protein (GHBP) is the extracellular portion of the GH receptor. Its concentrations in circulation are decreased in severe malnutrition, reflecting a decrease in tissue GH receptor abundance. IGFs are bound to 6 different binding proteins (IGFBPs). IGFBP-3 is relatively stable and is only depressed after prolonged periods of severe malnutrition. In contrast, IGFBP-1 is regulated acutely by nutrient intake, showing major elevations after overnight fasting and rapid postprandial decreases. IGFBP-2 is highly dependent on dietary protein intake. Nutritional factors may regulate the tissue availability and the biological actions of IGFs by their actions on IGFBPs.
Ketelslegers
J M
JM
Department of Internal Medicine, School of Medicine, Catholic University of Louvain, Brussels, Belgium.
Maiter
D
D
Maes
M
M
Underwood
L E
LE
Thissen
J P
JP
D000818:Animals; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D009747:Nutritional Physiological Phenomena; D013002:Somatomedins / Q000378:metabolism
D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D013006:Growth Hormone