noun, plural: somatostatins
A peptide hormone that occurs in two major forms: one that is involved in inhibiting gastric secretion and motility and the other in the inhibition of somatotropin release from the posterior pituitary
Somatostatin is one of the many hormones of vertebrates that are naturally produced. It interacts with the G protein-coupled somatostatin receptors.
Somatostatin, also referred to as the growth hormone-inhibiting hormone, is a peptide hormone. In humans, the precursor of somatostatin is encoded by SST gene. There are two active forms of somatostatin – one that is comprised of 14 amino acids and the other, 28 amino acids.
Based on the function, somatostatin may be described as: (1) gastrointestinal and (2) hypothalamic. The gastrointestinal somatostatin is secreted by the delta cells of in the pyloric antrum, the duodenum, and the pancreatic islets of the digestive system. Its function is to inhibit gastric secretion and motility. It also inhibits insulin and glucagon secretion.
The hypothalamic somatostatin is produced by the neuroendocrine cells of the ventromedial nucleus of the hypothalamus and released from the hypothalamohypophysial system. In this regard, somatostatin belongs to the group of hypothalamic hormones. In the anterior pituitary, somatostatin inhibits somatotropin release by the somatotropic cells.
- growth hormone-inhibiting hormone (GHIH)
- growth hormone release-inhibiting hormone (GHRIH)
- somatotropin release-inhibiting factor (SRIF)
- somatotropin release-inhibiting hormone (SRIH)