Control of the interdigestive myoelectric activity in dogs by the vagus nerves and pentagastrin.

In healthy, consious, intact fasted dogs, infusion of pentagastrin interrupted the interdigestive myoelectric complex in the stomach and small bowel and replaced it with activity that closely resembled that seen after feeding. After bilateral transthoracic vagotomy, pentagastrin infusion still interrupted the complex but now, in addition, upon stopping the pentagastrin, a premature activity front (phase III) of the complex was also followed by a reduction in the temporal regularity of the cycles of the complex. Fewer cycles per 10 hr occurred in most dogs after vagotomy, and the complexes were not as regularly interrupted by feeding a small meal of 50 g of meat as they had been before vagotomy. The results indicate that both neural and humoral influences have a role in controlling the interdigestive motor complex of dogs.