Minimum biological domain of xenin-25 required to induce anion secretion in the rat ileum

•Xenin-25 has a variety of physiological functions in the gastrointestinal tract.•The details of the biological domain that induce ion transport of xenin-25 remain poorly understood.•The minimum biological domain of xenin-25 to induce anion secretion in the ileum contains the C-terminal peptapeptide.•Arg at position 21 is important to retain the biological activity of xenin-25 to induce anion secretion in the rat ileum.