US-REGISTERED COMPANY
GH and IGF-1 are often mentioned as a single unit, but they represent two different levels of the same endocrine network. GH is a pituitary hormone, while IGF-1 is a separate growth factor acting through the IGF-1 receptor.
GH: a signal from the pituitary
Growth hormone is secreted by the anterior pituitary. Its release is regulated by GHRH, somatostatin, the ghrelin/GHS system and physiological rhythms. GH acts via its own GH receptor and can stimulate peripheral IGF-1 expression, including in the liver.
IGF-1: a separate receptor and intracellular pathways
IGF-1 binds the IGF-1 receptor, a receptor tyrosine kinase. IGF-1R activation involves signalling networks such as IRS-1/PI3K/AKT and Ras/MAPK, with effects that depend on cell type and experimental model.
PubMed: the IGF-1 signalling landscape
GH and IGF-1 are not interchangeable terms
| GH | IGF-1 | |
|---|---|---|
| Main source | Anterior pituitary | Several tissues, including the liver |
| Primary receptor | GH receptor | IGF-1 receptor |
| Position in the axis | Upstream endocrine signal | Peripheral growth factor and signalling mediator |
Broader overview of the GH axis
For the full map read How the GH axis works: GHRH → pituitary → GH → IGF-1. For specific profiles see Somatropin and IGF-1 LR3.
This content is educational and intended for understanding the scientific literature. It does not constitute medical advice or instructions for use.