Somatropin

Why Researchers Study Somatropin

Somatropin is recombinant human growth hormone (rHGH), a 191-amino-acid polypeptide identical in sequence to endogenous pituitary GH, produced via rDNA expression. It is the reference compound for growth-hormone research, used to study growth hormone receptor signalling and the GH/IGF-1 axis in controlled models.

Unlike GH secretagogues, which act on the pituitary receptors GHS-R1a or the GHRH receptor, somatropin is the hormone itself and binds the growth hormone receptor directly.

Mechanism of Action

Somatropin binds the transmembrane growth-hormone receptor (GHR) on target tissues. Receptor dimerisation activates the associated JAK2 tyrosine kinase, which phosphorylates STAT5; the pathway drives transcription of GH-responsive genes and, in hepatocytes, hepatic secretion of insulin-like growth factor 1 (IGF-1). IGF-1 mediates much of the downstream signalling attributed to GH, while GH also signals directly through the GHR in peripheral tissues.

Research Context

Investigational literature uses somatropin as a reference ligand in GH receptor signalling, IGF-1 expression and metabolic signalling studies. Its well-characterised pharmacology makes it a common positive control when benchmarking novel secretagogues and GHRH analogues.

Storage

Supplied as a lyophilised powder. Store lyophilised vials refrigerated.

For research purposes only. Not for human consumption.