In pancreas, endocrine portion is Islets of Langerhans which contains 3 kind of cells namely alpha cells (15−25%) , beta cells (70−80%) and delta cells. Alpha cells secrete glucagon hormone, beta cells secrete insulin hormone and delta cells secrete small amount of gastrin and somatostatin. Somatostatin also secreted by hypothalamus and some cells of digestive tract. The major action of pancreatic somatostatin is to inhibit the secretion of both insulin and glucagon.