Growth hormone (or somatotropin)

A polypeptide or glycoprotein hormone produced by the anterior pituitary gland.  It decreases the rate of carbohydrate uptake, enhances the mobilization of lipids from adipose tissue, and stimulates the production of insulin-like growth factors by the liver to enhance growth of muscle and bone, particularly through the engendering the release of somatomedin that influences the metabolism of carbohydrates, lipids, and proteins.  When deficient, the growth hormone can give rise to pituitary dwarfism in which height can vary from 3 feet (92 cm) to 4 feet (122 cm).  In contrast, an excess of the hormone can lead to gigantism, with heights measuring up to 7 feet (213 cm), but with little effect after puberty, and to acromegaly (thickening of bones of jaw, fingers and toes). 

See Arcuate nucleus, Gamma amino butyric acid (GABA), Glycoproteins, Hormones, Lipids, Peptides, Pituitary gland, Polypeptides, Proteins