Somatostatin, is a peptidehormone which is secreted endocrine by the pancreas during digestion.
Somatostatin occurs mainly in the gastrointestinal tract, in the hypothalamus and in the nerve endings. It inhibits the secretion of gastrin, gastric acid and pepsin, slows down the endocrine and exocrine secretion of the pancreas and reduces the secretion of growth hormone (hence the name). Figuratively speaking, somatostatin prevents both hypo- and hyperglycaemia under physiological conditions.
https://de.wikipedia.org/wiki/Somatostatin (Wikipedia CC-by-sa-3.0)