Abstract: KA8 peptide is a c-terminal octapeptide 30～37 of oxyntomodulin 1～37. Oxyntomodulin 1～29 is a glucagon, which can increasa the concentration of blood glucose, but oxyntomodulin has a obvious inhibition of gastrie acid secretion. In order to understand the KA8 biologieal activity, we have synthesized KA8 and injected to rats before administration of pentagastrin. The experiment showed that pentagastrin stimulated definitively gastric acid secretion. However, KA8 could eliminated the pentagastrin induced gastric acid secretion. Our result reveals that KA8 plaies probably a important role in the regulation of gastric acid secretion.

Key words: KA8 peptide, oxyntomodulin, pentagastrin, peptide synthesis