Growth Hormone Endocrine Index Glossary Growth Hormone Growth hormone, also known as somatotropin , is a protein hormone of about 190 amino acids that is synthesized and secreted by cells called somatotrophs in the anterior pituitary. It is a major participant in control of several complex physiologic processes, including growth and metabolism.
Growth hormone is also of considerable interest as a drug used in both humans and animals.
A majority of the growth promoting effects of growth hormone is actually due to IGF-1 acting on its target cells. Keeping this distinction in mind, we can discuss two major roles of growth hormone and its minion IGF-1 in physiology. Effects on Growth Growth is a very complex process, and requires the coordinated action of several hormones. The major role of growth hormone in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. Growth hormone does seem to have a direct effect on bone growth in stimulating differentiation of chondrocytes.