Specimen Information

Type

Gold, SST

Volume

2.0 ml

Transport Info

Centrifuge and immediately transfer serum to separate plastic tube
Frozen

Fasting Required?

True

Clinical Significance

Gastrin is a major gastrointestinal hormone. It serves to stimulate gastric acid secretion and exists in a number of molecular forms, differing from on another in the length of the polypeptide backbone and in derivatizations of individual amino acids. The three principal forms, G-17, G-34 and G-14, are named for the number of amino acids, which they contain.
Immunoassays for gastrin play an essential role in the identification of Zollinger-Ellison tumors (gastrinomas). These tumors are typically, but not invariably, associated with elevated gastrin levels, gastric acid hypersecretion and peptic ulcer disease.
In fasting subjects, gastrin normally circulates at levels of less than 100 pg/mL with some day to day variability. Fasting gastrin levels in patients with Zollinger-Ellison syndrome are typically very high, well above the reference range for healthy individuals.
Elevated values are also encountered in other conditions. Where gastric acid secretion is impaired, for example in pernicious anemia, gastrin levels are characteristically (and appropriately) increased. Hypergastrinemia and hypersecretion of gastric acid are also encountered in the absence of pancreatic or duodenal tumors. Thus, hypergastrinemia without gastrinoma may be found in pyloric obstruction with antrum distension, after vagotomy, in the “retained antrum” syndrome, and in some patients with ordinary peptic ulcer disease.