Somatostatin is a hormone that regulates a number of biological activities by inhibiting the release of other hormones, gastrointestinal activity, and cell reproduction.
It's also known as growth hormone inhibiting hormone, and it's generated in a variety of places, including the GI tract, pancreas, hypothalamus, and central nervous system (CNS).
It is also released by the brain and inhibits pituitary gland growth hormone secretion.