Glucagon is a hormone produced in the liver that increases blood sugar. It stimulates hepatic glucose production, counteracting the effects of insulin, thus raising blood sugar. Glucagon breaks down glycogen and synthesizes new glucose. It is secreted by the alpha cells in the islets of Langerhans in the pancreas and is produced in response to low blood sugar, fasting, exercise, and protein-rich meals.

The synthetic form of glucagon is used to treat low blood sugar, particularly in people with type 1 diabetes. Glucagon corrects a condition called hypoglycemia by raising blood sugar.

It also increases glucose production in the body, playing a role in the production of amino acids. It also has the ability to convert fat into fuel by breaking down triglycerides, thus balancing blood sugar levels and providing energy.

Where is Glucagon Hormone Produced?

Glucagon is a hormone responsible for raising blood sugar levels. It is produced by alpha cells, specialized cells located in the islets of Langerhans in the pancreas, and is secreted into the bloodstream. Glucagon's primary function is to raise blood sugar levels. This function differs from insulin in that it raises blood sugar levels when they drop.

Normal Values ​​of Glucagon Hormone

Normal glucagon levels in the body can vary depending on blood sugar levels or the laboratory doing the testing, but a typical reference range is 50 to 100 picograms per milliliter (pg/mL).

Basic Function and Effects of Glucagon

The main function of the glucagon hormone in the body is to regulate blood sugar levels and raise blood sugar in cases of hypoglycemia.

Normally, the body regulates blood sugar levels through the hormones glucagon and insulin. When blood sugar levels begin to drop or hypoglycemia develops, the pancreas secretes more glucagon. Glucagon secretion raises blood sugar levels.

To increase blood sugar levels, follow these steps:

• Glycogenolysis: Promotes glycogenolysis to convert glucose (glycogen) stored in the liver into a usable form, thereby releasing glucose into the bloodstream.
• Gluconeogenesis: Prevents the liver from taking up and storing glucose, allowing more glucose to remain in the blood. It also helps the body produce glucose from other sources, such as amino acids.

Low blood sugar levels in the setting of hypoglycemia can cause symptoms such as fainting, especially in people with type 1 diabetes. Glucagon may be needed to prevent these symptoms and raise blood sugar levels. While naturally produced in the body, glucagon supplements may also be necessary in cases of sudden low blood sugar. Using glucagon supplements in injection or powder form can help bring blood sugar levels back to normal.

Also, when blood sugar levels reach the level of hypoglycemia and glucagon hormone tends to rise excessively, the pancreas tries to bring blood sugar levels back into the normal range by secreting insulin.

Glucagon and Insulin: Functions and Differences

The main difference between glucagon and insulin is that they function oppositely: insulin lowers blood sugar, while glucagon raises it.

Glucagon and insulin are hormones that play important roles in regulating blood sugar in the body. Both are produced by different types of cells in the pancreas. Alpha cells in the pancreas produce and secrete glucagon, while beta cells produce insulin.

It has a blood sugar-increasing effect. Glucagon is secreted particularly when blood sugar levels begin to drop or in cases of hypoglycemia. Its primary effect is to break down glycogen stored in the liver, releasing glucose into the bloodstream.

Insulin, on the other hand, has a blood sugar-lowering effect. When blood sugar levels rise, especially after a meal, pancreatic beta cells secrete insulin. Insulin allows cells to take in and use glucose. It also reduces glucose production in the liver and promotes glucose storage in body cells.

Therefore, the mutual effects of glucagon and insulin play an important role in keeping blood sugar levels balanced.

Glucagon and Glycogen: Functions and Differences

Glycogen is a stored sugar in the body, the storage form of glucose. The body typically stores glycogen in the liver and muscles. Glucagon is a hormone that promotes the conversion of glycogen in the liver into glucose, which then enters the bloodstream and takes a form the body can use as energy. This allows the body to release glucose to meet its energy needs.

Which Organ Does Glucagon Hormone Affect?

It acts specifically on the liver. In the liver, glucagon stimulates the conversion of glycogen to glucose, thereby increasing the release of glucose into the bloodstream. This releases the glucose needed to meet the body's energy needs.

What Happens If Glucagon Hormone Is Low?

When glucagon levels are low, the body may have difficulty maintaining normal glucose metabolism. A decrease in glucagon can cause the following effects:

• Hypoglycemia (low blood sugar): A lack of glucagon can lead to lower-than-normal blood sugar levels. This condition is called hypoglycemia and can cause symptoms such as dizziness, shakiness, sweating, hunger, weakness, and even loss of consciousness.
• Energy deficiency: It triggers the conversion of glycogen to glucose in the liver, increasing the release of glucose into the bloodstream. When glucagon levels are low, the body may have a reduced ability to produce energy, leading to symptoms like weakness and fatigue.
• Impaired liver function: The liver produces glucose using glycogen stores. A drop in glucagon levels can prevent the liver from performing this function, leading to disruptions in metabolism and energy balance.

As a result, decreased glucagon can often lead to problems such as hypoglycemia and lack of energy, which can affect the body's normal functioning.

Does Glucagon Lower Blood Sugar?

No, glucagon doesn't lower blood sugar; on the contrary, it increases it. It triggers the conversion of glycogen stored in the liver to glucose, which is then released into the bloodstream. This process helps raise blood sugar levels and prevent hypoglycemia. Therefore, by increasing blood sugar, glucagon helps the body meet its energy needs.

Why is a Glucagon Test Done?

It is typically performed to evaluate the following situations:

• Determining the type of diabetes: This test may be performed to determine if a person has a rare pancreatic tumor such as an insulinoma. An insulinoma is a tumor that secretes excessive amounts of insulin, causing hypoglycemia. A glucagon test may be performed to rule out or diagnose conditions such as an insulinoma.
• Evaluation of hypoglycemia: The glucagon test can be used to investigate the causes of hypoglycemia in individuals with recurrent hypoglycemia episodes, especially when these episodes are unexplained. The test can help identify the underlying cause of hypoglycemia.
• Diagnosing pancreatic tumors such as glucagonoma: A glucagon test can be used to diagnose pancreatic tumors such as glucagonoma, which arise from the glucagon-producing cells of the pancreas. Glucagonomas can secrete excessive amounts of glucagon, leading to hyperglycemia (high blood sugar) and other symptoms.

For these reasons, the glucagon test can be an important tool for evaluating hormonal disorders and metabolic conditions. However, the specific use of this test may vary depending on a particular patient's condition and symptoms. Therefore, a doctor will evaluate a particular patient's clinical history and symptoms before ordering a glucagon test.