Somatostatin secretion in pancreas islets

A photomicrograph of a stained section through a normal human pancreas, showing delta cells producing somatostatin (red) in the islets of Langerhans. Somatostatin inhibits the secretion of many other hormones, including growth hormone, thyroid-stimulating hormone, insulin and glucagon. Certain pancreatic tumours cause enhanced somatostatin secretion, leading to mild diabetes. Somatostatin also reduces the rate of nutrient absorption by suppressing secretion of gastric acid, pepsin and gall bladder secretions, lowers the rate of gastric emptying and reduces smooth muscle contractions and blood flow in the intestine. It also has various effects on neural transmission and activity patterns.