Overview
rat IGF-I is fully biologically active when compared to standards. The ED50 shown in literature was calculated in two different methods: 1. Stimulation of protein synthesis in rat L6 myoblasts ED50 was found to be less than 30 ng/ml. 2. Type 1 IGF receptor binding assay ED50 was found to be less than 10 ng/ml.
Evidence indicates that IGF-I promotes cell survival by inhibiting apoptosis both in vivo and in vitro. IGF-I is also involved in the regulation of the migration of certain cell types1.
Alomone Labs Recombinant rat IGF-I protein promotes survival of PC12 cells.Dose-response curve of Recombinant rat IGF-I protein (#I-200) facilitation of survival of serum-deprived PC12 cells. Cell viability was determined by the XTT method and normalized to serum-supplemented control. EC50 was calculated at 12.5 ng/ml.
Insulin-like growth factor-I (IGF-I) belongs to the insulin family which is divided in two groups of peptides: 1- insulin and IGFs and 2- relaxin and insulin-like hormones. The structure of mature IGF-I is composed of a single polypeptide chain of 70 amino acids with 57 amino acids being identical across different organisms1,2.
IGF-I is a pleiotropic factor responsible for the regulation of several cellular processes depending on its concentration, cell type and the developmental stage of the organism.
IGF-I binds to IGF-I receptor and triggers the auto phosphorylation of the receptor and the activation of the insulin receptor substrates1.
In the embryonic brain IGF-I expression is relatively high and drops sharply in the adult brain except in the hippocampus and the subventricular zone-olfactory bulb. In adults IGF-I is mainly synthesized in the liver though a process regulated by the growth hormone (GH). IGF-I can cross the blood-brain-barrier by binding to the IGF-I receptor present on endothelial cells and is later picked up by astrocytes to be transferred to neurons or directly by neurons1,2.
Studies show that IGF-I influences neural stem cell proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. IGF-I also promotes adult neurogenesis by regulating neural stem cell number and differentiation1.
