Rat Growth Hormone

Growth hormone (GH) is a single-chain polypeptide hormone which is synthesized, stored and secreted by the somatotroph cells of the anterior pituitary gland. It stimulates growth, cell division and regeneration and controls metabolism both directly and through the generation of IGF-I. For example, GH acts by interacting with specific receptors on the cell surface where it activates the MAPK/ERK pathway and directly stimulates division and multiplication of chondrocytes. GH also activates the JAK-STAT signalling pathway and the production of IGF-I. The liver is a major target organ and along with adipocytes, is the principal site of IGF-I production which mediates some of the effects of GH.