Gastrin:
Why Gastrin Test?
CLINICAL INFORMATION
G-Cells secrete Gastrin and other gastric (acids) contents. As the food enters the stomach, the G-Cells are triggered and hence it releases its secretions into the gastric contents. The function of the gastric hormone is to promote digestion, enhance gastric motility, gastric mucosal growth, secretion of HCl into the stomach, reduce the gastric emptying rate etc. Gastrin also has minor effects on the liver, pancreas and intestines. The levels of gastrin hormone are counterbalanced by certain factors such as -high levels of acidity in the stomach (that gives feedback to reduce gastrin release), secretion of the hormone – Somatostatin - released by the pancreas (as the gastric contents empty the stomach). The gastrin test is primarily used to help screen, detect the excess production of gastrin (hyper-gastrinemia). This test also aids in the diagnosis of gastrin-producing tumors such as Gastrinomas, Zollinger-Ellison Syndrome (with secretions of very high levels of gastrin) Hyperplasia of G-Cells etc. During the Gastrin Test, the gastrin level is measured, during the fasting period and thus is more preferred for screening tests as it gives an accurate assessment (that helps in the diagnosis of the existing pathology pertained to its cause). Other gastrin tests include the “GST–Gastrin Stimulation Test” where gastrin hormone secretion is induced after ingestion of high-protein or protein-rich test meal and/or an alternative method of gastrin test triggered by injecting secretin into the vein called “intravenous secretin test”. Clinical manifestations of high gastrin levels include signs and symptoms of peptic ulcers in the stomach like abdominal pain, abdominal bloating, acid reflux, heartburn, burping, bleeding in GIT, decreased appetite, unintended weight loss etc. Risk factors for increased gastrin secretion are snacking just before bedtime, sleeping immediately after a heavy meal, intake of spicy and fatty foods, drinking carbonated drinks, intake of alcohol, tea, coffee with the food, people with intolerance and sensitivity to lactose and gluten, insulin etc. Causes of abnormal gastrin levels leading to gastritis are due to Zollinger-Ellison Syndrome, somatostatin (associated tumours), conditions related to MEN1 (Multiple Endocrine Neoplasia – Type 1), chronic atrophic gastritis (a condition resulting from long-term inflammation of the stomach lining that leads to the loss of acid-producing cells), pyloric obstruction (blockage at the junction between stomach and pancreas), tumours of the parathyroid gland, pituitary gland, bile reflux (backflow of bile into the stomach from the bile tract), infections like H pylori, chronic kidney failure, constant use of NSAIDs, stress etc. Some factors that may affect the gastrin test results are intake of a high protein diet, caffeine, medications such as antacids, H2 blockers, Proton Pump Inhibitors, calcium supplements, anti-depressants, stress etc. Complications of long-standing, untreated gastritis can lead to a severe loss of blood, increase the risk of developing stomach cancers, pernicious anaemia etc. Other additional tests include Immuno-Chemi-Luminometric Assay (ICMA), gastric function test, X-rays (look for gas under the diaphragm in case of perforation in the second part of duodenum etc), endoscopic ultrasound, Ga-DOTATATE PET – CT Scanning, upper endoscopy, blood tests for H pylori, stool test for fecal occult bleeding – black tarry stools etc.
General Instructions:
Sample Requirement: Specimen - Blood sample collected from the vein. Test Preparation: 12 hours Fasting Required (avoid coffee, caffeine drinks, alcohol, medications such as antacids, H2 blockers, proton pump inhibitors, aspirin etc, - for 24 hours prior to the test)
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
