(growth-hormone-release inhibiting hormone) a hormone produced by the hypothalamus and some extraneural tissues, including the gastrointestinal tract and pancreas (see islets of Langerhans), that acts to inhibit the secretion of many hormones. For example, in the pituitary gland it inhibits the release of *growth hormone (somatotrophin) and in the pancreas it suppresses secretion of insulin and glucagon. Somatostatin analogues are used to treat *acromegaly (caused by overproduction of growth hormone) and to relieve the symptoms caused by hormone-secreting neuroendocrine tumours, including *carcinoid tumours. They include lanreotide (also licensed for the treatment of thyroid tumours) and octreotide (also used to reduce vomiting in palliative care and to treat *oesophageal varices); gastrointestinal upsets (e.g. nausea, loss of appetite, abdominal pain, diarrhoea) are the most common side-effects.... somatostatin