Gastrin is an important gastrointestinal hormone that is secreted primarily by G cells. G cells are typical open cells with the most antrums, followed by the fundus, duodenum and jejunum. D cells of human islets can also secrete gastrin. Hypergastrinemia, which is divided into two types: high gastric acid hypergastrinemia and low gastric acidity or no acid hypergastrinemia. In patients with gastrinoma, serum gastrin levels are high, and more often accompanied by gastric mucosal hyperplasia, hypertrophy.
High gastric acid hypergastrinemia: seen in gastrinoma, excessive formation of gastric antral mucosa, residual sinus antrum, chronic renal failure. After the recovery of renal function, most of the gastrin levels returned to normal. If it could not be recovered, it often suggested the possibility of atrophic gastritis.
Low gastric acidity or no acid hypergastrinemia: seen in gastric ulcer, type A atrophic gastritis, after vagus nerve resection, hyperthyroidism.Hypogastrinemia: seen in type A atrophic gastritis, gastroesophageal reflux.
Gastrin reactivity is enhanced: seen in achalasia and duodenal ulcer disease.
Decayin reactivity is weakened: seen in cutaneous sclerosis.
In gastric cancer, the change of gastrin is related to the lesion site. Serum gastrin is significantly elevated in gastric cancer, while gastrin secretion is decreased in gastric sinus cancer.
Gastrointestinal CT examination blood test
Laboratory examinations must be summarized and analyzed based on objective materials and medical examinations, and several possible diagnostics are proposed, and then further examinations are performed to confirm the diagnosis. Such as basic gastric acid secretion rate, digestive tract X-ray, radioimmunoassay method for determination of gastrin, gastrointestinal endoscopic ultrasonography.
(1) Primary hypergastrinemia: CT cells proliferate due to genetic or chronic inflammation and Helicobacter pylori infection, which in turn increases secretion of gastrin and is absorbed into the blood, resulting in hypergastrinemia.
(2) secondary hypergastrinemia: due to chronic atrophic gastritis, the number of parietal cells is reduced, the acid-carrying capacity is weakened, and the gastric acid content of gastric juice is decreased (pH>4). Through the feedback mechanism, gastric G cells secrete a large amount of gastric secretion. It produces high gastrinemia.