Effects of ileal infusions of nutrients on motor patterns of canine small intestine

In the present study, effects of ileal infusions of nutrients on motor patterns of the proximal small intestine and on gastric emptying were investigated in dogs. An acaloric meal was administered orally, and equicaloric loads of amino acids, oleate, and glucose were infused into the ileum at different doses (0.3, 0.6, and 0.9 kJ/min). The computerized analysis of motor patterns was focused on the differentiation between stationary and propagated contractions recorded by closely spaced extraluminal strain gauges. All three nutrients exerted inhibitory effects on gastric emptying and on contraction force and frequency of the proximal small intestine. Additionally, the propulsive motor pattern induced by the acaloric meal was modulated by reducing the number of contraction waves and their length of spread. All the effects were dose dependent. Among the three nutrients, glucose significantly changed motility at lower doses compared with amino acids and oleate. We conclude that in dogs the ileal brake mechanism is induced by all three nutrients and that it influences not only contraction force and frequency but also the motor patterns of the proximal small intestine.