Plasma levels of insulin-like growth factor binding protein-1, and growth hormone binding protein activity from birth to the third month of life.
Serum levels of insulin-like growth factors (IGF-1 and IGF-2), insulin, insulin-like growth factor binding protein-1 (IGFBP-1), growth hormone (GH) and growth hormone-binding protein (GH-BP) activity were assessed in a group of healthy newborns and reevaluated at one and three months of life in six of them. A significant decrease in IGFBP-1 plasma levels was observed at one month (p < 0.002) and three months (p < 0.02) of life compared to cord blood values. IGF-1 plasma levels did not change during the first three months of life. In contrast, IGF-2 plasma levels increased significantly at three months of life compared to cord blood values (p < 0.002). GH plasma levels showed a significant decrease at three months of life (p < 0.03). GH-BP activity was low at birth and did not change significantly during the first three months of life. The low GH-BP activity may reflect the GH receptor status, indicating that GH receptors are poorly expressed in early infancy. The high IGFBP-1 plasma levels in newborns could be important in protecting them from hypoglycemia.
D000375:Aging / Q000097:blood; D002352:Carrier Proteins / Q000097:blood*; D005312:Fetal Blood; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D009994:Osmolar Concentration; D013002:Somatomedins / Q000032:analysis
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; C051815:somatotropin-binding protein