 In the periphery, neurotensin is found in enteroendocrine cells of the small intestine, where it leads to secretion and smooth muscle contraction.Neurotensin shares significant sequence similarity in its 6 C-terminal amino acids with several other neuropeptides, including neuromedin N (which is derived from the same precursor).This C-terminal region is responsible for the full biological activity, the N-terminal portion having a modulatory role.