Neurotensin in the human fallopian tube: immunohistochemical localization and effects of synthetic neurotensin on motor activity in vitro.

With the use of different region-specific antisera and the peroxidase-antiperoxidase (PAP) technique, neurotensin-immunoreactivity was found in nerve fibers of the human fallopian tube. Neurotensin-immunoreactive fibers occurred at blood vessels and in contact with smooth muscle cells of the muscular stratum. In vitro experiments with helical strips of the myometrium revealed dose-dependent excitatory actions of neurotensin on resting tension as well as on amplitude and frequency of spontaneous contractions. The results may suggest a neurotransmitter function of neurotensin in the regulation of human oviductal smooth muscle activity. Thus, neurotensin may be essential in the transport of the eggs through the fallopian tube.