Big gastrin (G-34) is a form of

gastrin Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. Gastrin ...

with 34

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

in its sequence. Big gastrin is a hormone produced by G cells and can be found inside of the stomach. G-34 promotes the secretion of

gastric acid Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the ...

in dogs. In

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s, the half life of this

peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A ...

is between 14.7 and 16.8 minutes. In humans, an over production of this hormone by

gastrinoma Gastrinomas are neuroendocrine tumors (NETs), usually located in the duodenum or pancreas, that secrete gastrin and cause a clinical syndrome known as Zollinger–Ellison syndrome (ZES). A large number of gastrinomas develop in the pancreas or duod ...

s leads to Zollinger-Ellison Syndrome. Big Gastrin Responses to Foods: Big gastrin (G34) is one form of gastrin predominate in circulation after a meal, another major form is called little gastrin (G17). Both forms of gastrin have been isolated from human

and hog antral mucosa. G34 is carboxy-amidated and can be sulphated or unsulphated at the tyrosin residues. Binding of gastrin to the receptors in stomach can cause the secretion of hydrochloric acids (HCl), the

. Duodenal ulcer patients tend to have higher than normal basal and maximal rate of gastric acid secretion, while gastric ulcer patients have lower than normal basal and maximal of gastric acid output. Comparing G34 in normal and

peptic ulcer Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines i ...

subjects by using

radioimmunoassay A radioimmunoassay (RIA) is an immunoassay that uses radiolabeled molecules in a stepwise formation of immune complexes. A RIA is a very sensitive in vitro assay technique used to measure concentrations of substances, usually measuring antigen conc ...

in fasting serum and after feeding, basal G34 was found similar in normal and duodenal ulcer but raised in gastric ulcer before meal. After a meal, the concentration of G34 was increased in both duodenal ulcer patients and gastric ulcer patients, which significantly higher than normal people.

References

Peptide hormones {{biochem-stub