Gastrin: Physiology and What Research Reports

What gastrin is

Gastrin is a peptide hormone of the gastrointestinal tract. A 2022 review covering gastrin from physiology to gastrointestinal malignancies described it as a hormone released from specialised endocrine cells of the stomach that regulates gastric acid secretion and exerts growth-promoting (trophic) effects on the gastric mucosa (PMID 35330921). Because it is a short, biologically active amino-acid chain, gastrin is often encountered in reading lists about gut peptides alongside cholecystokinin (CCK), ghrelin and secretin.

This page is for educational purposes only and is not medical advice; consult a licensed physician for any question about health, symptoms, laboratory results or medication. Gastrin is not described here as something a reader would use — the literature summarised below is laboratory, animal and clinical-chemistry research.

Where it is produced

The 2022 review placed gastrin production in the endocrine G cells of the gastric antrum, with release into the circulation and downstream stimulation of acid output through histamine-releasing and parietal-cell pathways (PMID 35330921). A 2016 review of gastrin and upper gastrointestinal cancers similarly described gastrin as the principal hormonal driver of gastric acid secretion and noted that sustained elevation of circulating gastrin (hypergastrinaemia) has been a recurring theme in upper GI research (PMID 27591354).

Molecular forms: G-17, G-34 and glycine-extended gastrin

Gastrin does not circulate as a single molecule. A 2009 review of gastrin-17 and gastrin-17-glycine reported that progastrin is processed into several products, including amidated gastrin-17 and the incompletely processed glycine-extended form, and that both amidated and glycine-extended peptides have been studied for biological activity in gastrointestinal cancers (PMID 20001914). This heterogeneity matters for interpretation: papers using the word "gastrin" may refer to different processed forms.

Gastrin is not the same as gastrin-releasing peptide

A common point of confusion is that gastrin-releasing peptide is a distinct bombesin-family neuropeptide rather than a form of gastrin. Researchers reported that GRP promoted migration in lung adenocarcinoma cells through a PI3K- and reactive-oxygen-species-dependent mechanism (PMID 28351312), work that belongs to a different receptor system from the gastrin/CCK-B literature.

What gastrin does in the body

Two functional themes dominate the reviews. The first is secretory: gastrin regulates gastric acid production, a role the 2022 review treated as its defining physiological action (PMID 35330921). The second is trophic: the same review and a 2016 upper-GI review both described gastrin as influencing proliferation of gastric mucosal cell populations, which is why chronically raised gastrin has been studied in the context of mucosal and neoplastic change (PMID 35330921, PMID 27591354).

Comparative work has explored additional roles. A 2024 study in Siberian sturgeon reported that gastrin reduced feeding in that species and that the effect operated via the cholecystokinin receptor B, which the authors framed as a neglected appetite-related function of the peptide (PMID 38381278). That was a fish model, and the paper's findings should not be read across to humans.

How gastrin is measured and studied

Circulating gastrin is measured by immunoassay in clinical chemistry, and the reliability of those measurements has itself been a research subject. A 2012 Clinical Chemistry paper on pitfalls in diagnostic gastrin measurement reported that assays differ in how they recognise the various gastrin forms, so results obtained with different methods are not necessarily interchangeable (PMID 22419747). For readers who encounter a gastrin result, that paper is the reminder that method matters as much as the number.

Antibody quality is part of the same problem. A 2019 data article reported recharacterisation of an aged polyclonal gastrin antibody, documenting its performance so that laboratories relying on legacy reagents could interpret their own results (PMID 31011600). Gastrin research therefore spans three practical layers: the peptide itself, the receptor, and the reagents used to detect both.

Why gastrin appears in peptide research reading

Most of the modern gastrin literature is oncology-adjacent mechanistic work, and it is the main reason the term shows up outside gastroenterology textbooks. A 2022 cell study reported that gastrin/CCK-B receptor signalling promoted invasion and metastatic behaviour in gastric cancer cells by upregulating MMP-2 and VEGF expression (PMID 34976177). A 2018 experimental cell research paper reported that gastrin increased adhesion of AGS-GR gastric cancer cells by modulating α2β1 integrin signalling (PMID 29253536). A 2016 study reported that connective tissue growth factor was activated by gastrin and was involved in gastrin-induced migration and invasion (PMID 27179776).

Colorectal tissue has been examined too: a 2000 Gut study reported that gastrin and gastrin receptor activation appeared as an early event in the adenoma–carcinoma sequence (PMID 11076881). A broad 2006 review of gastrin and cancer collated the then-available evidence linking gastrin and its receptors to growth of gastrointestinal tumour tissue (PMID 16054292/).

Gastrin in Research Contexts: What Studies Report

The verified literature here does not contain human administration trials with dosing schedules, so no doses, durations or tolerability profiles are described on this page. What the reviews did report is a safety-relevant biological signal rather than a drug side-effect list: the 2016 upper-GI review discussed hypergastrinaemia as a state of interest because of gastrin's trophic effects on gastric mucosa (PMID 27591354), and the 2006 review summarised evidence connecting gastrin and its receptors to tumour cell growth in the gastrointestinal tract (PMID 16054292/). The 2022 review likewise framed gastrin as a hormone whose physiology and malignant-disease associations are difficult to separate (PMID 35330921).

Limitations of the current evidence

• Several of the mechanistic findings came from cultured cancer cell lines rather than intact organisms (PMID 34976177, PMID 29253536).
• Appetite-related findings were reported in a fish species, not in mammals (PMID 38381278).
• Measurement heterogeneity complicates comparison of gastrin concentrations across studies and laboratories (PMID 22419747).
• "Gastrin" can denote several processed peptides with potentially different activity (PMID 20001914).

References

• Gastrin: From Physiology to Gastrointestinal Malignancies (Function, 2022)
• Gastrin and upper GI cancers (Current Opinion in Pharmacology, 2016)
• Gastrin/CCK-B Receptor Signaling Promotes Cell Invasion and Metastasis by Upregulating MMP-2 and VEGF Expression in Gastric Cancer (Journal of Cancer, 2022)
• By modulating α2β1 integrin signalling, gastrin increases adhesion of AGS-GR gastric cancer cells (Experimental Cell Research, 2018)
• Pitfalls in diagnostic gastrin measurements (Clinical Chemistry, 2012)
• Neuropeptide gastrin-releasing peptide induces PI3K/reactive oxygen species-dependent migration in lung adenocarcinoma cells (Tumour Biology, 2017)
• Gastrin and cancer: a review (Cancer Letters, 2006)
• The production and role of gastrin-17 and gastrin-17-gly in gastrointestinal cancers (Protein and Peptide Letters, 2009)
• Neglected function of gastrin to reduce feeding in Siberian sturgeon (Acipenser baerii) via cholecystokinin receptor B (Fish Physiology and Biochemistry, 2024)
• Gastrin and gastrin receptor activation: an early event in the adenoma-carcinoma sequence (Gut, 2000)
• Recharacterization data for a geriatric gastrin polyclonal antibody (Data in Brief, 2019)
• Connective tissue growth factor is activated by gastrin and involved in gastrin-induced migration and invasion (BBRC, 2016)