- Last Update On : 2013-02-02
This test is used to help diagnose a gastrinoma in patients with with fasting gastrin levels that are below the diagnostic level of 1000 pg/mL. The test is performed as follows:
- A baseline gastrin level is drawn
- An intravenous bolus of 2 to 3 U secretin per kilogram of body weight is administered over 30 seconds.
- Serum gastrin levels are then measured at 2, 5, 10, 15, and 20 minutes.
Normally, no change or a slight suppression of gastrin concentration will be seen. Patients with gastrinoma demonstrate a paradoxical increase of 100 to 200 pg/mL in serum gastrin at 5 minutes with maximum levels reaching several thousand pg/mL. Approximately 90% of patients with gastrinoma will have a positive secretin test.
See gastrin for specimen requirements.