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.

Application

Insulin-like Growth Factor-I human has been used:in modified Dulbecco minimal essential medium for in vitro culture of testicular cellsin culture media, to study its effect on steroidogenesis during testicular developmentin culture media for in vitro assay of splenic pro-erythroid cell growth and differentiation

Biochem/physiol Actions

Insulin-like growth factor I (IGF-I) plays a critical role in cellular energy metabolism and growth and development, especially prenatal growth.

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.

General description

Insulin-like growth factor I (IGF-I) is localized on human chromosome 12q23.2.

Physical form

Lyophilized from 0.2 µm filtered solution in 50 mM acetic acid.

Reconstitution

Reconstitute in water