Secretin: a hormone and a diagnostic agent
Clinical review pending
Secretin stimulates the pancreas and is used in diagnostic tests. An overview of its function, uses and side effects.
What is secretin?
Secretin is a hormone made of 27 amino acids. It is normally released in the small intestine and prompts the pancreas to secrete a bicarbonate-rich fluid that neutralizes stomach acid. The FDA-approved product ChiRhoStim contains synthetic human secretin. It is used for diagnosis, not treatment: it triggers a measurable response from the pancreas or a measurable release of gastrin. An earlier product containing synthetic porcine secretin was discontinued in favor of the human form. Source
The discovery of secretin
Secretin was the first hormone ever identified. In 1902, the physiologists William Bayliss and Ernest Starling showed that a substance from the intestinal lining travels through the blood to the pancreas and stimulates it. Starling later coined the term “hormone” for chemical messengers of this kind. The discovery is regarded as the beginning of endocrinology. Today, though, secretin’s clinical use is diagnostic, not therapeutic.
How does secretin work?
Secretin binds to receptors on the duct cells and acinar cells of the pancreas and promotes the release of a watery, bicarbonate-rich fluid. In a diagnostic test, the secretion is collected after the dose, or the response is captured with imaging. This shows how well the gland responds, for example when a disorder of its exocrine function is suspected. Secretin also stimulates gastrin release from the abnormal cells of a gastrinoma. The characteristic paradoxical rise in gastrin helps diagnose this tumor.
Because the measured response is what matters, secretin is given as a single intravenous dose under controlled conditions. In clinical studies, secretin-enhanced imaging detected changes in the pancreatic ducts with higher sensitivity than imaging without stimulation 1.
Is secretin FDA-approved?
Yes. Synthetic human secretin, sold as ChiRhoStim, was approved by the FDA in 2004 2. Its diagnostic uses are summarized in the table.
What is secretin used for?
Secretin serves as a diagnostic aid in three tests: assessing exocrine pancreatic function, triggering a gastrin response when a gastrinoma is suspected, and improving visualization of the ducts during an ERCP. It is given by a doctor as part of a specific examination and is not taken on an ongoing basis.
What side effects have been reported?
According to the prescribing information, the most common side effects after a single diagnostic dose include:
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Nausea.
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Vomiting.
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Temporary flushing of the skin with a feeling of warmth.
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Stomach discomfort.
Studies at a glance
| Diagnostic use | What secretin does |
|---|---|
| Diagnosing exocrine pancreatic insufficiency | Stimulates secretion by the pancreas. |
| Diagnosing a gastrinoma | Stimulates gastrin release. |
| Endoscopic retrograde cholangiopancreatography (ERCP) | Helps identify the pancreatic ducts. |
Sources cited in the original article
Sources: FDA prescribing information for ChiRhoStim; a study of secretin-stimulated pancreatic imaging (Sherman et al., Gastroenterology, 2014, DOI: 10.1053/j.gastro.2014.05.035 1 ), indexed on PubMed; historical accounts of the Bayliss and Starling discovery of secretin.
Origin and editorial review status
Adapted for Nutrient Desk from the original article. The statements and source attributions of the original still require clinical review. This draft has not been cleared for indexing.