Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. Gastrin levels can be used for investigation of patients suspected of achlorhydria or pernicious anemia.
Intraluminal stomach pH is the main factor regulating gastrin production and secretion. Rising gastric pH levels result in increasing serum gastrin levels. Other weaker factors that stimulate gastrin secretion are gastric distention, protein-rich foods and elevated serum calcium levels.
Achlorhydria is the most common cause of elevated serum gastrin levels. The most common cause for achlorhydria is treatment of gastroduodenal ulcers, nonulcer dyspepsia or gastroesophageal reflux with proton pump inhibitors (eg. omeprazole). Other causes of hypo- and achlorhydria include chronic atrophic gastritis with or without pernicious anemia, gastric ulcer and gastric carcinoma.
If serum B12 levels are significantly low, a serum gastrin level above the reference range makes it more likely a patient is suffering from pernicious anemia. Gastrin levels can also be used for investigation of patients suspected of having Zollinger-Ellison syndrome.
- Pernicious anaemia
- Gastric ulcer
- Zollinger-Ellison syndrome