IGF-1 Axis
Definition
The IGF-1 Axis (Insulin-like Growth Factor 1 Axis) is a signalling cascade that links growth hormone secretion to tissue-level growth, repair, and metabolic regulation. It represents one of the most important endocrine pathways in mammalian biology and is a primary target of numerous research peptides.
Components of the Axis
The axis consists of several interconnected components:
- Growth Hormone (GH) — Released from the pituitary in response to GHRH and ghrelin stimulation
- Hepatic IGF-1 production — GH binding to liver receptors triggers IGF-1 synthesis and secretion
- IGF-1 Receptors (IGF-1R) — Tyrosine kinase receptors on target tissues that mediate IGF-1 effects
- IGF Binding Proteins (IGFBPs) — Six binding proteins that regulate IGF-1 bioavailability and half-life
- Negative feedback — IGF-1 inhibits GH release at both hypothalamic and pituitary levels
Downstream Signalling
IGF-1R activation triggers PI3K/Akt/mTOR and RAS/MAPK/ERK cascades, promoting protein synthesis, cell proliferation, and anti-apoptotic signalling. The mTOR pathway is particularly relevant as it integrates nutrient availability with growth factor signalling.
Relevance to Peptide Research
The IGF-1 axis is the convergence point for most GH-related peptide research. GHRH analogues, ghrelin mimetics, and GH secretagogues all ultimately work by elevating IGF-1 levels. Serum IGF-1 is the standard biomarker for assessing GH-axis peptide activity in preclinical and clinical studies.
Related Peptides
Peptide profiles that reference “IGF-1 Axis” in their research content.