Gastrinutsöndringen

Gastrinutsöndringen refers to the physiological process by which the hormone gastrin is released. Gastrin is primarily produced by G-cells located in the stomach, specifically in the gastric antrum, and to a lesser extent in the duodenum. Its secretion is a crucial component of regulating gastric acid production and motility.

The primary stimulus for gastrin release is the presence of food in the stomach, particularly proteins and amino acids. Distension of the stomach wall also plays a role. Vagal nerve stimulation, particularly through parasympathetic pathways, can also promote gastrin secretion. Conversely, factors such as a low gastric pH (acidity) act as an inhibitory signal, reducing gastrin release.

Once released into the bloodstream, gastrin travels to the parietal cells in the stomach lining. There, it binds to cholecystokinin-B receptors, stimulating these cells to secrete hydrochloric acid (HCl) into the stomach lumen. This acid is vital for breaking down food, killing ingested microorganisms, and activating pepsinogen into pepsin, an enzyme essential for protein digestion. Gastrin also promotes the growth of the gastric mucosa and influences gastric motility, contributing to the mixing of food with digestive juices.

Disruptions in gastrinutsöndringen can have significant health implications. Excessive gastrin production, known as hypergastrinemia, can lead to increased acid secretion, potentially contributing to peptic ulcers and Zollinger-Ellison syndrome, a rare condition characterized by gastrin-producing tumors. Conversely, insufficient gastrin can impair digestion and nutrient absorption.