S. Pellissier et al., PERIPHERAL NEUROTENSIN PARTICIPATES RN THE MODULATION OF PREPRANDIAL AND POSTPRANDIAL INTESTINAL MOTILITY IN RATS, Neuropeptides, 30(5), 1996, pp. 412-419
The present study was undertaken to determine whether neurotensin is i
nvolved in the regulation of the intestinal postprandial motor respons
e and, if so, whether the regulatory pathway depends upon peripheral o
r central neurotensin secretion, Neurotensin, injected by the i.v. rou
te (5 mu g/kg) during the fasting state, induced firstly an increased
irregular spiking activity during 30-40 min. This effect was followed
by an increase of frequency of the myoelectrical complexes during 60 m
in, When injected by the i.c.v. route, neurotensin (0.5 mu g/kg) reinf
orced the fasting motility pattern of the small intestine after a late
ncy of 70 min. Neurotensin was ineffective on ?he colon, The neurotens
in receptor antagonist SR 48692 (200 mu g/kg i.v.) reduced the duratio
n of the postprandial motor response of the small intestine and blocke
d the late postprandial phase on the proximal colon while it suppresse
d the early postprandial phase on the distal colon. When administered
i.c.v. (20 mu g/kg), SR 48692 had no effect. It is concluded that neur
otensin modulates intestinal postprandial motility essentially by a pe
ripheral regulatory pathway, Endogenous neurotensin is involved in the
maintenance of the postprandial motility pattern on the small intesti
ne and the proximal colon while it is involved in the initiation of th
is response on the distal colon, This suggests that endogenous neurote
nsin acts via both endocrine and nervous mechanisms.