Gastrins in human antrum, duodenum and peripheral circulation.

Previous studies have shown that arginine-stimulated gastrin release disappears after pyloric antrectomy in the human, while conflicting evidence indicates that gastrin is released by the human duodenum. The present study reconciles this conflict by showing that the major form of gastrin in the pyloric antrum is the heptadecpeptide form, while the duodenum contains mainly "big" and almost no heptadecapeptide gastrin. Fasting serum samples contain mostly "big" gastrins, while stimulated serum contains increased proportions of the heptadecapeptide and minigastrin species. It is suggested that local factors operative at the different G-cell sites determine the nature of gastrin released since "big" gastrins occur in most sites containing gastrin.