Human growth hormone (hGH) is a member of the somatotropin/prolactin family of hormones which play an important role in growth control. The growth hormone locus of chromosome 17 contains the GH1 and 4 related genes. These five genes have a remarkable level of sequence identity. Alternate splicing produces five isoforms, ranging in size from 19 kDa up to 24 kDa.
The human growth hormone ELISA equipment measures GH levels in serum, plasma and cell culture media. This assay can only recognize natural and recombinant Hu GH. The Human GH solid phase sandwich ELISA (enzyme linked immunosorbent assay), measures the amount of target bound between a matched pair of antibodies.
The pituitary's somatotroph cells produce HGH. It works by binding to membrane receptors belonging to the cytokine-receptor subfamily. It is responsible for stimulating body growth by activating the liver and other tissues that secrete IGF-1. It stimulates myoblast differentiation and proliferation. It stimulates protein synthesis and amino acid uptake in muscle, and other tissues.
Short stature and growth hormone deficiency can be caused by mutations or deletions of the gene. The pituitary gland produces growth hormone to support childhood growth and maintain tissues and organs through life. HGH is a 22,000-dalton protein that contains 191 amino acids.
HGH initiates many growth-promoting pathways, including the MAPK/ERK pathway which stimulates and outgrows cartilage chondrocytes. The JAK/STAT pathway promotes IGF-1 production. HGH has been shown to increase calcium retention, increase muscle volume, promote lipolysis and increase protein synthesis. It also stimulates the growth of all organs, glucose availability, and the immune system.