What is the Origin of IGF-I Concentration?

The term IGF-I originates from the discovery of its insulin-like metabolic effects and its role as a key factor in mediating the effects of growth hormone, leading to its classification as a somatomedin. The concentration is a crucial biomarker in endocrinology for diagnosing growth disorders, monitoring GH replacement therapy, and assessing nutritional status. Its stability, compared to the pulsatile nature of GH, makes it an invaluable diagnostic tool.

What is the Mechanism of IGF-I Concentration?

The primary mechanism involves Growth Hormone (GH) binding to its receptors in the liver, stimulating the hepatocyte to synthesize and release IGF-I into the bloodstream. Once released, IGF-I binds to IGF-I receptors on target cells, activating intracellular signaling cascades, notably the PI3K/Akt pathway, which promotes cell proliferation, differentiation, and survival. The majority of circulating IGF-I is bound to binding proteins, which modulate its half-life and bioavailability at the tissue level.

IGF-I Concentration ∞ Area

IGF-I Concentration

Meaning

IGF-I Concentration refers to the measurable level of Insulin-like Growth Factor-I, a polypeptide hormone primarily synthesized and secreted by the liver in response to growth hormone (GH) stimulation, circulating in the serum. IGF-I acts as the main mediator of GH’s anabolic and growth-promoting effects on bone, muscle, and other tissues. Clinical assessment of its concentration provides a stable, integrated measure of overall growth hormone status and somatotropic axis function.