Gastrin

Introduction

As a Nurse Practitioner with autonomous practice in Florida, it’s essential to keep patients informed about the various biomarkers that can influence their health. One such biomarker, Gastrin, plays a significant role in the digestive system. Understanding its function, the implications of its levels, and how it interacts with other bodily processes is crucial for maintaining optimal health.

What is Gastrin?

Gastrin is a hormone produced by G cells located in the pyloric antrum of the stomach. Its primary role is to stimulate the release of Hydrochloric Acid (HCL) from the parietal cells of the stomach. This acid plays a vital role in the digestion of food and the absorption of nutrients. Gastrin also stimulates the Chief Cells to secrete pepsinogen, the inactive form of the digestive enzyme pepsin, and induces the release of enzymes from the pancreas. Additionally, it plays a role in the release of bile from the gallbladder, which is essential for fat digestion.

How is Gastrin Released?

Gastrin release is stimulated by several factors, including:

• Presence of Partially Digested Proteins: When proteins, polypeptides, and individual amino acids are present in the stomach, they stimulate Gastrin release.
  
• Stomach Distension: The stretching of the stomach’s antrum by food also triggers the release of Gastrin.
  
• Hypercalcemia: Elevated calcium levels can stimulate Gastrin secretion.
  
• Alkaline Environment: An alkaline environment in the stomach can also promote the release of this hormone.

   

Conversely, Gastrin release is inhibited by:

• Acid Presence: The presence of Hydrochloric Acid (HCL) in the stomach creates a negative feedback loop that inhibits Gastrin release.
  
• Certain Hormones: Hormones such as Somatostatin, Secretin, Gastroinhibitory Peptide (GIP), Vasoactive Intestinal Peptide (VIP), Glucagon, and Calcitonin can inhibit Gastrin secretion.

   

Clinical Implications of Gastrin Levels

Low Gastrin Levels

Low levels of Gastrin can indicate several conditions, including:

• Hypochlorhydria: Characterized by decreased production of stomach acid, hypochlorhydria can lead to digestive issues and nutrient malabsorption. Associated lab findings may include increased globulin levels, altered protein levels, and changes in MCV and MCH.
  
• Biliary Insufficiency: This condition involves a decreased output of bile from the gallbladder, often associated with elevated bilirubin and alkaline phosphatase levels.
  
• Pancreatic Insufficiency: Reduced pancreatic enzyme output leads to digestive problems. Lab findings may reveal decreased WBC count, albumin, and increased GGT.

   

High Gastrin Levels

Elevated Gastrin levels are associated with:

• Gastric Inflammation: Similar to hypochlorhydria, but with the possibility of decreased globulin unless inflammation is severe. Supportive therapy may be needed before initiating HCL therapy.
  
• Gastric and Peptic Ulcers: These conditions exhibit increased Gastrin levels, and lab results may show elevated AST, changes in iron levels, and alterations in MCV and MCH.
  
• Zollinger-Ellison Syndrome (ZE): A serious condition where excessive Gastrin is produced, usually by a tumor (gastrinoma). Gastrin levels can exceed 200 pg/ml, requiring immediate medical intervention.

   

Interfering Factors

Certain factors can interfere with Gastrin levels, leading to false readings:

• Falsely Decreased Levels: Currently, no known factors cause falsely decreased Gastrin levels.
  
• Falsely Increased Levels: No known factors have been identified to cause falsely increased levels.

   

Drug Associations

Medications can affect Gastrin levels:

• Decreased Levels: Anticholinergics, Tricyclic antidepressants, H2 blockers (e.g., Zantac, Tagamet), and Proton Pump Inhibitors (e.g., Prilosec) can lower Gastrin levels.
  
• Increased Levels: Antacids and coffee consumption can elevate Gastrin levels.

   

When to Consider Gastrin Testing?

Testing for Gastrin levels may be appropriate if you suspect any of the following dysfunctions or diseases:

• Hypochlorhydria
  
• Pancreatic Insufficiency
  
• Biliary Insufficiency
  
• Gastric Inflammation
  
• Gastric or Peptic Ulcer
  
• Zollinger-Ellison Syndrome

   

Conclusion

In conclusion, a comprehensive evaluation by a functional medicine telehealth in Florida facilitates identification of cellular and molecular imbalances underlying digestive and hormonal dysfunction. By integrating evidence-based allopathic therapies with IV Therapy medical care services—where nutrient absorption and GI health are prioritized—we offer a holistic framework to rebuild resilience and optimize wellness. Call (904) 799-2531 or schedule online to request your personalized digestive health assessment.

Further Reading

• Jensen, R. T. (2020). Gastrinoma. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK441842/1

• Ito, T., Jensen, R. T. (2016). Consensus guidelines update for the management of functional pancreatic neuroendocrine tumors, including gastrinomas. Pancreas, 45(6), 744-752. https://pmc.ncbi.nlm.nih.gov/articles/PMC4849884/2

• Sato, Y., et al. (2023). Diagnostic performance of the normal range of gastrin calculated from pathological evaluation of the stomach. BMC Gastroenterology, 23, 123. https://pmc.ncbi.nlm.nih.gov/articles/PMC10199508/3

• Norton, J. A., et al. (2006). Assessment and prediction of long-term cure in patients with Zollinger-Ellison syndrome after gastrinoma resection. Annals of Surgery, 244(6), 866-874. https://pubmed.ncbi.nlm.nih.gov/17108779/