Growth hormone (GH1) binds GHR to activate an intracellular signal transduction pathway that leads to the synthesis and secretion of IGF1. The GHR gene also encodes a soluble form called growth hormone binding protein (GHBP) that binds GH1 and likely serves as a reservoir of GH1 in the plasma.
Disruption of GHR causes dwarfism in mice, enhances insulin (INS) sensitivity, and significantly extends longevity [3]. Mice with disrupted GHR do not live longer when subjected to calorie restriction, which suggests a role for GHR and possibly the associated GH1/IGF1 signalling in caloric restriction [1773]. Humans with mutations in GHR suffer from Laron syndrome, which is characterized by short stature. Whether the ageing process is modified in patients with Laron syndrome remains unclear [1345]. One study found evidence of cancer protection In individuals with GHR deficiency, but a normal lifespan [2035].