What is secretin (a hormone)

From the Guidelines

Secretin is a hormone that plays a crucial role in digestion by stimulating the pancreas to produce bicarbonate-rich pancreatic juice, thereby neutralizing stomach acid in the duodenum. It is released when acidic chyme from the stomach enters the duodenum, triggering secretin to enter the bloodstream 1. Once released, secretin primarily stimulates the pancreas to produce bicarbonate-rich pancreatic juice, which helps neutralize stomach acid in the duodenum, creating the optimal pH environment for digestive enzymes to work. Additionally, secretin decreases gastric acid secretion, stimulates bile production from the liver, and increases water and bicarbonate secretion from the pancreatic and biliary ducts. Medically, synthetic secretin is sometimes used as a diagnostic tool in pancreatic function tests and in certain imaging procedures to assess pancreatic duct abnormalities. It can also be used in the diagnosis of gastrinomas (tumors that secrete gastrin) through the secretin stimulation test, as mentioned in the guidelines for the management of gastroenteropancreatic neuroendocrine tumors 1. The use of secretin in the diagnosis of gastrinomas is particularly important, as it can help differentiate gastrinoma from atrophic gastritis, and guide treatment decisions 1. In the context of gastroenteropancreatic neuroendocrine tumors, secretin is a valuable tool for diagnosis and management, and its use is supported by the guidelines for the management of these tumors 1.

Some key points to consider when using secretin in clinical practice include:

• Secretin stimulation test can be used to diagnose gastrinomas and other neuroendocrine tumors 1
• Synthetic secretin can be used as a diagnostic tool in pancreatic function tests and imaging procedures 1
• Secretin plays a crucial role in digestion by stimulating the pancreas to produce bicarbonate-rich pancreatic juice 1
• The use of secretin in clinical practice should be guided by the guidelines for the management of gastroenteropancreatic neuroendocrine tumors 1

From the FDA Drug Label

When injected intravenously, sincalide stimulates gallbladder contraction and reduction in size. The evacuation of bile that results is similar to that which occurs physiologically in response to endogenous cholecystokinin. Sincalide also stimulates pancreatic secretion and intestinal motility causing pyloric contraction and slows gastric emptying Concurrent administration of sincalide with secretin increases both the volume of pancreatic secretion and the out-put of bicarbonate and enzymes.

Secretin is not defined in the provided text, however, it is mentioned that concurrent administration of sincalide with secretin increases both the volume of pancreatic secretion and the output of bicarbonate and enzymes. 2

• The text does not provide a definition of secretin.
• Secretin is used in combination with sincalide to stimulate pancreatic secretion. 2
• The mechanism of action of sincalide is described, but not the mechanism of action of secretin. 2

From the Research

Definition of Secretin

• Secretin is a hormone that stimulates the pancreas to secrete bicarbonate-rich fluid to help neutralize the acidity of the stomach contents 3.
• It is also used as a diagnostic tool to stimulate gastrin release in patients with suspected Zollinger-Ellison syndrome (ZES) 4.

Role of Secretin in Zollinger-Ellison Syndrome

• Secretin stimulation tests are used to diagnose ZES by measuring the increase in gastrin levels after secretin infusion 5, 4.
• The test is based on the principle that secretin stimulates gastrinoma cells to secrete gastrin, while inhibiting normal G cells 4.
• The rapid intravenous infusion of secretin is followed by gastrin level evaluation at specific intervals post-infusion to aid in differentiating ZES cases from other hypergastrinemic states 4.

Clinical Use of Secretin

• Secretin is used in the diagnosis of ZES, particularly in differentiating it from other causes of hypergastrinemia 4.
• It is also used to localize the primary tumor and its metastases in patients with ZES 4.
• However, the use of secretin is not directly related to the treatment of ZES, which typically involves proton pump inhibitors and other medical therapies 6, 7.