Gastrin

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Formal name: Gastrin
Related tests: Helicobacter pylori, gastric acid

At a Glance

Why Get Tested?

To detect an overproduction of gastrin, to help diagnose Zollinger-Ellison syndrome (ZE syndrome), to help diagnose multiple endocrine neoplasia type 1 (MEN-1) and to monitor for recurrence of a gastrin-producing tumour (gastrinoma)

When to Get Tested?

When you have peptic ulcers and/or diarrhoea and abdominal pain that your doctor suspects is caused by excess gastrin; periodically to monitor for a gastrinoma recurrence

Sample Required?

A blood sample taken from a vein in your arm.

Test Preparation Needed?

You should fast for 12 hours and avoid alcohol for 24 hours before the test. Your doctor may also ask you to stop taking certain stomach medications for several days before the test.

The Test Sample

What is being tested?

This test measures the amount of gastrin in the blood. Gastrin is a hormone that regulates the production of acid in the stomach. It is produced by special cells called G-cells in the stomach during the digestive process. When food is eaten, the stomach becomes less acidic, promoting gastrin production. Gastrin in turn stimulates parietal cells to produce stomach acid. As acidity increases in the stomach, food is broken down and gastrin production falls. This feedback system normally results in low to moderate levels of gastrin in the blood. Rare conditions such as G-cell hyperplasia and Zollinger-Ellison (ZE) syndrome can cause an overproduction of gastrin and stomach acid. These conditions can lead to peptic ulcers that can be difficult to treat.

ZE syndrome is characterised by high gastrin levels, greatly increased stomach acid production, and by peptic ulcers due to gastrin-producing tumours called gastrinomas. Gastrinomas can form in the pancreas, the duodenum and rarely in other parts of the body. More than half of these tumours are malignant - causing cancer that can spread to other parts of the body, such as the liver. Even tiny tumours can produce large quantities of gastrin.

How is the sample collected for testing?

A blood sample is taken by inserting a needle into a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

You should fast for 12 hours and avoid alcohol for 24 hours prior to the test. Your doctor may also ask you to stop taking certain stomach medicines for several days before the test.

The Test

Common Questions

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.