Jejunal regulation of gastric motility patterns: Effect of extrinsic neural continuity to stomach

This study was designed to determine the role of extrinsic gastric innervation in mediating the inhibitory effects of jejunal infusion of mixed nutrients on canine interdigestive gastric motility patterns. Four dogs underwent transection of all extrinsic and intrinsic neural continuity to the stomach except for careful preservation of vagal innervation (stage 1). Antral manometry catheters, antral electrodes, intestinal electrodes, and a jejunal infusion catheter were placed. After a 2-wk recovery, stage 1 studies of myoelectric and contractile activity of the stomach and small bowel during fasting were recorded on four occasions during infusion of isomolar solutions of either nonnutrient NaCl (150 mM) or mixed nutrients (50% Meritene solution) into the jejunum at 2.9 ml/min for 6 h. Identical studies (stage 2) were repeated after completion of extrinsic denervation of the stomach by supradiaphragmatic vagotomy. In stage 1 studies, jejunal nutrients (83 kcal/h) inhibited the characteristic interdigestive cyclic motility patterns in the stomach and duodenum for ≥ 172 min during jejunal infusion of mixed nutrients. After completion of extrinsic denervation (stage 2), jejunal infusion of nutrients had the same effects with inhibition of cyclic motility patterns in the stomach and small intestine. We concluded that inhibition of interdigestive gastric motility patterns by jejunally infused nutrients is mediated by hormonal mechanisms and not by nonvagal or vagal extrinsic neural input to the stomach.