Neurotensin changes the motor pattern in canine ileum from propulsive to segmenting.

Modulation of ileal propulsive motility by different doses of neurotensin has been determined in detail. In conscious dogs neurotensin (2.5, 5, and 10 pmol/kg/min) was intravenously infused during the propulsive motor pattern induced by an acaloric viscous meal. Motor patterns were recorded by seven closely spaced strain gauge transducers and analyzed by a computerized method. Luminal transit was measured fluoroscopically. Neurotensin changed the propulsive motor pattern induced by the acaloric meal into a segmenting pattern. Effects were dose-dependent and most striking at a dose of 10 pmol/kg/min. The transit of luminal contents decreased from 20 to 8 cm/min. This was achieved by the increase in the number of stationary contractions (31 vs 55%), the reduction in the length of contraction spread (3.8 vs 1.8 cm), and the decrease in the number of contractions (11.5 vs 9.2 contractions/min). The contraction force was enhanced from 67 to 107 mN. Because of the marked effects on ileal motor patterns, neurotensin might be involved in the regulation of digestive motility in the distal small intestine.