To conduct a detailed study of the influence of GH signalling on AgRP neurons, the scientists bred genetically modified mice with AgRP-specific
GH receptor ablation (called AgRP GHR knockout mice).
He then talked about dopamine agonist's therapy,
GH Receptor agonists, medical treatment of prolactinomas and Cushing's syndrome.
identified a new longevity-associated allele consisting of a splice isoform of the
GH receptor (GHR) lacking exon 3 (d3-GHR).
In mice with liver
GH receptor (GH-R) knockout, metabolic syndrome (MetS), steatohepatitis, increased inflammation, liver fibrosis, and hepatic tumor develop [4].
It is caused by homozygous mutation of the
GH receptor (GHR) gene; the literature describes about 300-500 patients with different mutations [5-7].
Indeed, stimulated JAK2 adds a phosphate group to specific tyrosine residues on the cytoplasmic domain of the
GH receptor. Therefore, using its Src homology 2 (SH2) domain, STAT5 binds to these phosphorylated tyrosine residues [84].
It has also been demonstrated that androgens can increase periosteal bone growth even in the absence of the
GH receptor and with no increase in IGF-I.
For production of circulatory IGF 1, actions of GH are started by its binding to
GH receptor (GHR) on the surface of liver cells [9].
However, the effect of GH therapy on the final height is substantially variable depending on several clinical and genetic factors such as polymorphisms related with
GH receptor and/or IGFBP3 gene, young age, and bone age delay at the start of GH treatment.
Fewer DNA breaks and increased apoptosis were found in cell cultures exposed to oxidant agents added with serum obtained from subjects with
GH receptor deficiency [128].
After GH binding to growth hormone receptor (GHR), tyrosine kinase janus kinase 2 (JAK2) is activated, which in turn phosphorylates multiple tyrosines within both itself and the
GH receptor, as well as multiple signalling pathways.
Additionally, increased affinity of GH binding proteins (GHBP) and
GH receptor desensitization further displays the complexity of the hypothalamic-pituitary axis.