English
General description
Insulin-like growth factor I (IGF-I) is localized on human chromosome 12q23.2.[1]
Application
Insulin-like Growth Factor-I human has been used:
in modified Dulbecco minimal essential medium for in vitro culture of testicular cells[2][3]
in culture media, to study its effect on steroidogenesis during testicular development[4]
in culture media for in vitro assay of splenic pro-erythroid cell growth and differentiation[5]
Biochem/physiol Actions
IGF-I also known as somatomedin C, is secreted from the liver into circulation in a process regulated by pituitary growth hormone (GH) and so it mediates the growth-promoting activity of GH. In the developing embryo IGF-I is expressed primarily by mesenchymal-derived cells. After birth IGF-I expression in most extrahepatic tissues declines and hepatic expression of IGF-I becomes GH-regulated. Expression of IGF-I outside the liver is regulated differently, depending on the specific tissues. For example, gonadotropins and sex steroids regulate IGF-I expression within the reproductive system, while parathyroid hormone and sex steroids regulate IGF-I expression in bone. IGF-I is produced in several human tumors. IGF-I is mitogenic for a variety of cells including fibroblasts, osteoblasts, smooth muscle cells, fetal brain cells, neuroglial cells, and erythroid progenitor cells. IGF-I exerts its actions exclusively through the IGF-I receptor (IGF-IR). IGF-I induces endothelial cell migration and is involved in the regulation of angiogenesis.
IGF-I, also known as somatomedin C, mediates the growth-promoting activity of GH (growth hormone). IGF-I induces endothelial cell migration and is involved in the regulation of angiogenesis. IGF-I exerts its actions through the IGF-I receptor.
Insulin-like growth factor I (IGF-I) plays a critical role in cellular energy metabolism and growth and development, especially prenatal growth.[6]
Physical form
Lyophilized from 0.2 μm filtered solution in 50 mM acetic acid.
Preparation Note
Reconstitute in water
Analysis Note
The biological activiy is calculated by the dose-dependent proliferation of murine BALBC/3T3 cells. ED50 corresponds to a specific activity of at least 1 x 105 units/mg.
