What is the Origin of GH-IGF-I Axis?

The axis was scientifically elucidated through decades of endocrinological research focused on pituitary function and its systemic effects. The understanding of GH as the primary regulator and IGF-I as the main effector molecule established the functional relationship that defines the axis. This knowledge forms the basis for diagnosing and treating conditions related to growth hormone deficiency or excess.

What is the Mechanism of GH-IGF-I Axis?

Growth Hormone is released in a pulsatile manner, binding to GH receptors on target cells, most notably hepatocytes in the liver. This binding triggers the JAK-STAT signaling pathway, leading to the synthesis and secretion of IGF-I. Circulating IGF-I then acts on its own receptors in peripheral tissues, mediating most of the anabolic and mitogenic effects of GH, including protein synthesis and tissue repair, thereby completing the feedback loop.

GH-IGF-I Axis

Meaning

The GH-IGF-I Axis is a central neuroendocrine cascade responsible for regulating somatic growth, metabolism, and cellular proliferation throughout the lifespan. The axis comprises Growth Hormone (GH) secreted by the pituitary gland, which stimulates the liver and other tissues to produce Insulin-like Growth Factor-I (IGF-I). This tightly regulated system acts as a key anabolic pathway, influencing bone density, muscle mass, and body composition. Clinically, its function is monitored to assess growth disorders and age-related decline in tissue maintenance.