Insulin-like growth factor 1 and hair growth

The document reviewed the role of Insulin-like Growth Factor 1 (IGF-1) in hair growth, emphasizing its function as a mitogen and morphogen in hair follicle development. IGF-1 was shown to stimulate hair follicle cell proliferation and play an anti-apoptotic role, potentially extending the anagen phase of the hair cycle. While in vitro studies indicated that IGF-1 increased hair follicle growth, in vivo studies did not show significant effects on hair or wool growth with systemic or local IGF-1 administration. Transgenic animal studies suggested that overexpression of IGF-1 could enhance fiber growth, but these effects were not sustained. The document highlighted the importance of IGF-1 receptors and binding proteins in mediating these effects and suggested that future research should focus on these interactions to better understand hair growth regulation.