Effect of central sympathectomy on gastric and small intestinal myoelectric activity and plasma motilin concentrations in the dog.

Using a canine model, we studied fed and fasting gastric and small intestinal myoelectric activity and plasma motilin concentrations before and after transection of the spinal cord between the second and third thoracic segments. In sham-operated dogs, migrating complexes returned to normal by the second day after operation. Immediately after spinal cord transection, migrating complexes cycled in jejunum and ileum but not in the stomach and duodenum. After 11 and 15 days, migrating complexes returned to the duodenum and stomach, respectively. Plasma motilin concentrations did not cycle in animals without duodenal migrating complexes but returned to a normal cyclical pattern when duodenal migrating complexes returned. Feeding interrupted migrating complexes after cord transection and sham operation. The data observed in animals after 15 days suggest that myoelectric activity in fasted dogs and conversion of the fasted to the fed state of myoelectric activity are not under the control of supraspinal, sympathetic pathways.