Effect of Total Sympathectomy and of Decentralization on Migrating Complexes in Dogs

The effect of total sympathectomy and of decentralization on interdigestive myoelectric activity of the stomach and small intestine and on cycling levels of plasma motilin were studied in conscious dogs. In controls, 98.3% ± 7.9% of the migrating myoelectric complexes (mean ± SD) originated in the stomach. In sympathectomized dogs, 38.17% ± 16.7% originated in the stomach, 35.8% ± 12.3% in the duodenum, and 26.3% ± 4.3% in the jejunum. In decentralized dogs, 5.3% ± 1.4% of the migrating myoelectric complexes originated in the stomach, 71.0% ± 16.5% in the duodenum, and 23.9% ± 17.4% in the jejunum. Cycling of plasma motilin was not affected by long-term sympathectomy but coordination of peak levels of plasma motilin and initiation of gastric migrating myoelectric complexes was disrupted in decentralized dogs. These data suggest that central nervous input is required for initiation of migrating myoelectric complexes in the stomach and that central vagal but not central sympathectic input is essential for cycling of plasma motilin.