Human Secretin

Pancreas. Source: Grey's Anatomy, 1918.

Human secretin is an injectible synthetic hormone used to diagnose disease and locate structures in the pancreas. Secretin is normally produced by cells in the duodenum (small intestine) and signals the pancreas to regulate the pH of the small intestine.

Other Names

• ChiRhoStim (US)
• Secreflo (US)

Uses

Human secretin is a synthesized hormone that is similar to the secretin made in the small intestine. Human secretin is used to:

• Stimulate the pancreas to release secretions, including bicarbonate, to aid in the diagnosis of pancreatic exocrine dysfunction (an inability to digest food properly due to mucus obstructing the release of enzymes that break down food)

• Help the stomach release the hormone gastrin to aid in the diagnosis of a tumor in the pancreas or small intestine

• Help the pancreas release secretions to help show certain areas of the intestine during a special x-ray test called an endoscopic retrograde cholangiopancreatography (ERCP)

How Human Secretin Is Taken

Each vial of human secretin contains 16 mcg of purified human secretin, 1.5 mg of L-cysteine hydrochloride, 20 mg of mannitol and 0.9 mg of sodium chloride. When reconstituted with 8 mL sodium chloride for injection, the concentration of human secretin is 2 mcg/ml.

Dosages are:

• 0.2 mcg/kg of body weight for the diagnosis of exocrine pancrease dysfunction
• 0.2 mcg/kg of body weight for identification of the ampulla of vater and accessory papilla during ERCP
• 0.4 mcg/kg of body weight for the stimulation of gastric secretin to aid in the diagnosis of gastroma.

A test dose of 0.2 mcg is indicated prior to giving the indicated dose of human secretin. The test dose will rule out any allergic reaction or hypersensitivity to the drug.

How It Works

The main function of human secretin is to increase the volume and bicarbonate concentration of pancreatic secretions. These secretions are normally released when secretin (manufactured in the small intestine) sends a signal to the pancreas. This signal is sent when the pH of the small intestine decreases because of acidic stomach contents passing through the digestive system.

Injected secretin stimulates the exocrine pancreas (the secreting part of the pancreas). The amount of bicarbonate released by the pancreas after human secretin administration can indicate the level of functioning of the exocrine pancreas.

In addition, the amount of gastrin (a hormone that stimulates the secretion of gastric acid (HCl) in the stomach) produced by the pancreas can be measured after human secretin injection. An increase in gastrin production may indicate the presence of a gastrinoma (gastrin secreting tumor in the pancreas or small intestine).

Finally, the pancreatic secretions resulting from administration of human secretin can be visualized during ERCP. The visualization of the excretion can localize the ampulla of Vater and accessory papilla of the pancreas. These structures may otherwise be difficult to visualize.

Benefits

Human secretin is a useful tool for diagnosing pancreatic disease.

Side Effects

Some common side effects with human secretin include:

• Nausea
• Flushing (skin turns red and warm)
• Stomach or abdominal pain
• Vomiting

Risks

Human secretin may cause an allergic reaction. A person should receive a test dose of Human secretin to check for an allergic reaction before the full dose is given. A test dose is especially important if the person has allergies or asthma.

Precautions

Human secretin may be less effective:

• After an operation called a vagotomy (done to lower the amount of acid in the stomach)
• With certain anticholinergic medications
• In patients with inflammatory bowel disease.

People who have alcoholic or other liver disease may have a stronger reaction than others to human secretin.

Human secretin should not be used in someone with acute pancreatitis.

The drug should also be avoided in anyone who:

• Is trying to become pregnant, are already pregnant, or are breast-feeding
• Has allergies or asthma
• Is taking other medicines, including prescription and non-prescription medicines, vitamins, and herbal supplements. Some medicines may affect how human secretin works and the combination should be discussed with the prescribing physician or pharmacist.

History

Discovery

Human secretin received FDA approval on April 5, 2002.

Manufacturer

Human secretin is manufactured in the United States as Secreflo by the RepliGen Corporation.

It is also manufactured as ChiRhoStim by ChiRhoClin, Inc.

Controversy

After reports that children autism showed marked improved in symptoms after receiving secretin, more than 100 children with autistic disorders may have received secretin injections. Studies have failed to show an improvement in autism with the administration of human secretin. ^[1] The National Institutes of Health (NIH) released a news alert in October of 1998 regarding the use of secretin to treat autism. ^[2]

Research

Recent discoveries

• A recent study from Ireland showed that CT scanning of the pelvis after the administration of human secretin led to greater enhancement of the pancreas with greater tumor conspicuity, than imaging without secretin. ^[3]

Future research

• The use of secretin to aid in MRCP (Magnetic Resonance Pancreatography) in children is being studied. ^[4]
• The use of human secretin and MRCP to evaluate known or suspected intraductal papillary mucinous neoplasms of the pancreas is being studied. ^[5]
• Human secretin is being used with Multidetector Computed Tomography (MDCT) of the pancreas. The combination is being used to evaluate chronic pancreatitis. The study is looking at whether the secretin enhances the resolution of the MDCT. ^[6]
• A study is underway to evaluate whether secretin-enhanced CT is a worthwhile screening test for pancreatic cancer. ^[7]

Clinical Trials

• Check here for Human Secretin Clinical Trials

• There is one ongoing clinical trial available at ClinicalTrials.gov: Cancer of the Pancreas Screening Study (CAPS 3)

References

1. ↑ Owley T, McMahon W, Cook EH, et al. Multisite, double-blind, placebo-controlled trial of porcine secretin in autism. J Am Acad Child Adolesc Psychiatry. 2001 Nov;40(11):1293-9. Abstract
2. ↑ National Institutes of Health. The Use of Secretin To Treat Autism
3. ↑ O'Connell AM, Lyon SM, O'Sullivan P, et al. Secretin-assisted CT of the pancreas: improved pancreatic enhancement and tumour conspicuity. Clin Radiol. 2008 Apr;63(4):401-6. Epub 2008 Jan 31. Abstract
4. ↑ ClinicalTrials.gov. Secretin Enhanced MRCP for Evaluation of Pancreatic Duct in Pediatric Population
5. ↑ ClinicalTrials.gov. Secretin Enhanced MRCP for Evaluation of the Known or Suspected Intraductal Papillary Mucinous Neoplasms of the Pancreas
6. ↑ ClinicalTrials.gov. Secretin Enhanced Multidetector CT Pancreatography for Evaluation of Known or Suspected Chronic Pancreatitis
7. ↑ ClinicalTrials.gov. Secretin (ChiRhoStim) Pancreas Perfusion for Pancreatic Adenocarcinoma

External Links

FDA.gov: Human Secretin