Localization of neurotensin-immunoreactive cells in the small intestine of man and various mammals.

Antibodies against synthetic bovine neurotensin were raised in rabbits and used to demonstrate neurotensin-immunreactive cells by immunohistochemical methods. In the jejunum and ileum of all species investigated (man, dog, monkey, cat, rabbit, sheep, rat, mouse, hamster, chinese hamster, gerbil, pig and guinea pig) cells were present in the mucosa, which reacted specifically with antineurotensin serum using the indirect immunofluorescence and peroxidase-antiperoxidase methods. In the monkey Tupaia the distribution of neurotensin-immunoreactive cells was examined by investigating serial sections through the entire gastro-entero-pancreatic (GEP) endocrine system, again showing most neurotensin-immunoreactive cells in the jejunum and ileum. The functional role of the presence of neurotensin immunoreactivity in the gut is discussed.