Gastrin (serum) | Laboratory research

General Information

Gastrin is a hormone produced by G cells in the antral part of the stomach. Gastrin stimulates gastric juice secretion of hydrochloric acid (HCl), pepsin and intrinsic factor and motility of the antral part of the stomach.
There are several molecular forms of gastrin in the bloodstream: G-34 ("large gastrin") and G-14 ("minigastrin"). Gastrin concentration depends on circadian rhythms and is related to feeding.

Determination of gastrin is important in the diagnostics of gastrinomas (Zollinger-Ellison syndrome). (Gastrinoma is a gastrin-producing tumor localized in the pancreas or duodenal wall).

In healthy people, the amount of fasting gastrin does not exceed 100 pg/ml, while in Zollinger-Ellison syndrome it is significantly higher than the upper limit of normal.
Neuroendocrine tumors associated with Zollinger-Ellison syndrome are characterized by increased gastric acidity and gastroduodenal ulcer disease, often associated with diarrhea and steatorrhea (excretion of undigested fat in the stool). A gastrin level of 500-600 pg/ml in a patient with hyperacid gastritis often indicates a gastrinoma. 15-20% of Zollinger-Ellison syndrome patients also have other endocrine tumors: parathyroid adenomas, insulinomas, pituitary and adrenal tumors (Cushing's syndrome), Werner's syndrome (multiple endocrine tumors type I).
In 62% of cases, gastrinomas are malignant, and 44% of patients develop metastases. Gastrinomas are mostly localized in the pancreas, sometimes in the wall of the duodenum. Rarely it is located in the stomach.
An increase in the gastrin index is also observed in other conditions, such as: pernicious anemia (the level of gastrin increases in proportion to the decrease in gastric acidity), obstruction of the pyloric part of the stomach, post-vagotomy condition, gastric ulcer disease, and others.
Preparation of the patient: the study is performed on an empty stomach. It is necessary that 12-14 hours have passed since the last meal.
Study material: Venous blood

Reference norms:

0 – 12 days: 69 – 190 ng/l
From 13 days to 10 months: 55 - 186 ng/L
> 1 year and above: 13 – 115 ng/l

Interpretation of results

A basal gastrin level >1000 pg/mL in patients with gastroduodenal ulcer with increased gastric acidity is suggestive of Zollinger-Ellison syndrome.

Increased serum gastrin

It is noted in the following situations:
Stomach carcinoma
Stomach and duodenal ulcer disease
Pernicious anemia
Gastric antral G cell hyperplasia
Vagotomy – without gastric resection
Hyperparathyroidism
Pyloric obstruction
Chronic, end-stage renal failure

Decreased serum gastrin

It is observed in the following pathologies:
Antrectomy with vagotomy
Hypothyroidism

Important information:

A false increase in serum gastrin may be observed if the study was performed after a meal (not fasting), if the patient is elderly, as well as in the case of insulin resistance and post-gastroscopy. H2 receptor blockers, steroids, calcium preparations also cause a false increase in gastrin levels.