Gastrin

This is one of the peptide hormones of the digestive system secreted by the gastric antrum mucosa, pancreas, and duodenal G cells. It is a polypeptide encoded by the GAS gene located on chromosome 17 (17q21) of the duodenal cells. Gastrin secretion is stimulated by factors such as stomach distension, vagus nerve stimulation, incompletely digested food proteins, hypercalcemia. Its secretion is inhibited by high acidity of gastric juices, hormones somatostatin, secretin, and calcitonin. There are 3 forms of gastrin found in the blood – gastrin-34 (big gastrin), gastrin-17 (little gastrin), and gastrin-14 (minigastrin). The numbers indicate the number of amino acids in the polypeptide chain. Gastrin also affects other functions of the stomach and the digestive tract glands: it activates the differentiation of border cells, stimulates pepsinogen secretion from chief cells of the gastric mucosa, activates gastric peristalsis, pancreatic juice secretion, gallbladder contractions, and reduces the tone of the esophageal sphincter.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė