IGF-1 LR3 exerts its effects primarily through activation of the IGF-1 receptor (IGF-1R), a tyrosine kinase receptor.
- Receptor binding: It binds with high affinity to IGF-1R, but with low affinity to IGFBPs, prolonging its action.
- Signaling pathway activation: Binding to IGF-1R activates the PI3K/Akt and MAPK/ERK pathways.
- Anabolic effects: The PI3K/Akt pathway promotes muscle protein synthesis, hypertrophy, and inhibition of muscle atrophy.
- Metabolic effects: It stimulates glucose and amino acid uptake into cells, promoting an anabolic state.
- Differences from natural IGF-1: Its low binding to IGFBPs allows for a higher free and active concentration in tissues.