Pentagastrin

Pentagastrin is a synthetic pentapeptide analog of gastrin, the endogenous hormone that stimulates gastric acid secretion. It contains the C-terminal tetrapeptide sequence of gastrin (Trp-Met-Asp-Phe-NH2), which represents the minimum fragment retaining full biological activity at the CCK2 (gastrin) receptor.

The compound was developed as a standardized, stable alternative to natural gastrin extracts for diagnostic gastric acid secretion testing. Pentagastrin stimulation tests measure maximal acid output capacity, helping diagnose conditions such as Zollinger-Ellison syndrome (gastrin-secreting tumors), atrophic gastritis, and pernicious anemia.

Pentagastrin's mechanism involves CCK2 receptor activation on enterochromaffin-like (ECL) cells, stimulating histamine release, which then activates H2 receptors on parietal cells to promote acid secretion. It also has direct effects on parietal cells. This cascade makes pentagastrin valuable for research into the multi-component regulation of gastric acid secretion.

While pentagastrin stimulation tests have become less common with the availability of serum gastrin measurements and endoscopy, the compound remains valuable for gastric physiology research, CCK receptor characterization, and studies of acid secretion mechanisms in health and disease states.