Xenin-8 TFA, a C-terminal octapeptide derived from the 25-amino acid peptide Xenin belonging to the neurotensin/xenopsin family, is biologically active. It enhances basal insulin secretion and amplifies glucose-stimulated insulin release in a dose-dependent manner (EC50=0.16 nM) [1].

Xenin-8 TFA增强了由精氨酸诱导的胰岛素释放（提高了40%），并增强了对精氨酸（增强了60%）、Carbachol（增强了50%）的胰高血糖素反应。Xenin-8 TFA对抗了高葡萄糖浓度诱导的胰高血糖素释放抑制[1]。