61912-98-9

Insulin-like Growth Factor-I human has been used:

• in modified Dulbecco minimal essential medium for in vitro culture of testicular cells
• in culture media, to study its effect on steroidogenesis during testicular development
• in culture media for in vitro assay of splenic pro-erythroid cell growth and differentiation

IGF-I also known as somatomedin Cis 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 differentlydepending on the specific tissues. For examplegonadotropins and sex steroids regulate IGF-I expression within the reproductive systemwhile 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 fibroblastsosteoblastssmooth muscle cellsfetal brain cellsneuroglial cellsand erythroid progenitor cells. IGF-I exerts its actions exclusively through the IGF-I receptor (IGF-IR). IGF-I induces endothelial cell mig