Somatostatin

What is somatostatin?

Somatostatin is a hormone that regulates a variety of bodily functions by hindering the release of other hormones, the activity of your gastrointestinal tract and the rapid reproduction of cells.

Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, skin, muscles and other tissues. These signals tell your body what to do — or stop doing — and when to do it.

Many different tissues produce somatostatin, including tissues in your:

• Gastrointestinal (GI) tract: The GI tract is a series of hollow organs joined in a long, twisting tube from your mouth to your anus. These organs make up most of your digestive system.
• Pancreas: Your pancreas is a glandular organ in your abdomen that secretes several enzymes to aid in digestion and several hormones, including glucagon and insulin. It’s surrounded by your stomach, intestines and other organs.
• Hypothalamus: The hypothalamus is a part of your brain that maintains your body’s internal balance, which is known as homeostasis. It plays a significant role in directing your pituitary gland, an endocrine gland below it, to release certain hormones.
• Central nervous system (CNS): Your brain and spinal cord make up your CNS. Your brain uses your nerves to send messages to the rest of your body.

Other names for somatostatin include:

• SS, SST or SOM.
• Growth hormone inhibitory hormone (GHIH).
• Somatotropin release-inhibiting factor (SRIF).
• Somatotropin release-inhibiting hormone (SRIH).

Somatostatin medication

Healthcare providers use a synthetic form of somatostatin to treat certain health conditions, including:

• Certain gastrointestinal diseases.
• Acromegaly (a rare condition in which your body produces too much growth hormone).
• Neuroendocrine tumors (NETs).
• Other endocrine conditions.

What is the function of somatostatin?

The primary function of somatostatin is to prevent the production of other hormones in your endocrine system and certain secretions in your exocrine system. Your endocrine system consists of glands that release hormones directly into your bloodstream. Endocrine glands include your thyroid, pituitary gland and adrenal glands. Your exocrine system consists of glands that release substances through a duct. Exocrine glands include salivary glands, sweat glands and glands within the gastrointestinal tract.

Basically, somatostatin works to turn off the faucet and the flow of certain hormones and secretions when your body doesn’t need them (temporarily) anymore.

Somatostatin also stops the unnatural rapid reproduction of cells such as those that may form tumors. In addition, somatostatin acts as a neurotransmitter in your central nervous system. A neurotransmitter is a signaling molecule that a neuron releases to affect another cell.

Somatostatin affects several different areas of your body:

• In your hypothalamus, somatostatin stops the release of hormones your pituitary gland makes, including growth hormone, thyroid-stimulating hormone and prolactin.
• In your pancreas, somatostatin prevents (inhibits) the release of pancreatic hormones, including insulin, glucagon and gastrin, and pancreatic enzymes that aid in digestion.
• In your gastrointestinal (GI) tract, somatostatin reduces gastric secretion, which is stimulated by the act of eating. It also limits the release of gastrointestinal hormones, including secretin and gastrin.
• In your central nervous system (CNS), somatostatin modifies neurotransmission and memory formation.

What causes somatostatin release?

Scientists don’t yet fully understand how our bodies regulate the release of somatostatin and what causes tissues to release it. So far, they do know that several different cells and substances, such as proteins, play a role in causing somatostatin release.

One study on somatostatin revealed that glucose (sugar), the main form of energy your body uses, not only regulates somatostatin release but also plays a role in the production of somatostatin. The scientists behind the study detected insulin-stimulated somatostatin (insulin-inhibiting somatostatin) release only when there were low blood glucose levels and glucagon-stimulated somatostatin (glucagon-inhibiting somatostatin) when there were high blood glucose levels.

In other words, since insulin decreases blood glucose levels, your body releases somatostatin to stop insulin release when you have low blood glucose to prevent your levels from dropping further.

What conditions are related to somatostatin issues?

The main condition related to somatostatin issues is a very rare endocrine tumor called somatostatinoma. The tumor originates in your pancreas or gastrointestinal tract and produces excess amounts of somatostatin.

Somatostatinoma can occur randomly or in association with certain genetic syndromes, including:

• Multiple endocrine neoplasia (MEN) type 1: This is a rare genetic condition in which multiple tumors affect different aspects of your endocrine system.
• Neurofibromatosis type 1 (NF1): This is an inherited condition that causes cafe-au-lait spots (flat patches of light brown or coffee-colored skin) and benign tumors.
• Von Hippel-Lindau disease: This is a rare inherited condition that can cause benign or malignant tumors in your brain, spinal cord, eyes, kidneys, pancreas and adrenal glands.

Excess somatostatin results in an extreme reduction of the release of many other endocrine hormones. Symptoms can be similar to symptoms of many other conditions, so somatostatinoma can be difficult to diagnose.

There are very few reports of someone having lower-than-normal levels of somatostatin.

What tests can check my somatostatin levels?

Since somatostatin issues are rare, healthcare providers typically only use a blood test called somatostatin-like-immunoreactivity (SLI) to check somatostatin levels to diagnose somatostatinoma, a very rare tumor that produces excess somatostatin.

When should I see my healthcare provider about my somatostatin levels?

Issues with somatostatin levels are rare, so you likely won’t need to have your somatostatin levels checked. However, if you have a first-degree relative (parent or sibling) that has been diagnosed with multiple endocrine neoplasia type 1, neurofibromatosis type 1 or Von Hippel-Lindau disease, it’s important to tell your healthcare provider. These inherited (passed through the family) conditions can put you at risk of developing somatostatinoma.

A note from Cleveland Clinic

Somatostatin is an important hormone that affects many aspects of your body. Luckily, somatostatin usually works as it should, as issues with somatostatin and somatostatinomas are rare. If a member of your family has been diagnosed with an inherited condition that puts them at risk for developing a somatostatinoma, let your healthcare provider know. They can run some tests to see if you could also have the condition.