page_title: Somatostatin
section_title: Brain
hierarchical_section_title: Somatostatin / Production / Brain
caption_attribution_description: ISH image showing somatostatin gene expression in the adult mouse.
context_page_description: Somatostatin, also known as growth hormone-inhibiting hormone or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones. Somatostatin inhibits insulin and glucagon secretion.
  Somatostatin has two active forms produced by the alternative cleavage of a single preproprotein: one consisting of 14 amino acids, the other consisting of 28 amino acids.
  Among the vertebrates, there exist six different somatostatin genes that have been named SS1, SS2, SS3, SS4, SS5 and SS6. Zebrafish have all six. The six different genes, along with the five different somatostatin receptors, allow somatostatin to possess a large range of functions.
  Humans have only one somatostatin gene, SST.
context_section_description: Somatostatin is produced by neuroendocrine neurons of the ventromedial nucleus of the hypothalamus. These neurons project to the median eminence, where somatostatin is released from neurosecretory nerve endings into the hypothalamohypophysial system through neuron axons. Somatostatin is then carried to the anterior pituitary gland, where it inhibits the secretion of growth hormone from somatotrope cells. The somatostatin neurons in the periventricular nucleus mediate negative feedback effects of growth hormone on its own release; the somatostatin neurons respond to high circulating concentrations of growth hormone and somatomedins by increasing the release of somatostatin, so reducing the rate of secretion of growth hormone.
  Somatostatin is also produced by several other populations that project centrally, i.e., to other areas of the brain, and somatostatin receptors are expressed at many different sites in the brain. In particular, populations of somatostatin neurons occur in the arcuate nucleus, the hippocampus, and the brainstem nucleus of the solitary tract.
caption: Sst expression in the adult mouse.  Allen Brain Atlases
exif: {}