A model of jejunoileal in vivo neural isolation of the entire jejunoileum: transplantation and the effects on intestinal motility

Abstract

The effects of intestinal transplantation on enteric physiology have not been well studied. Our aim was to determine the effect of jejunoileal transplantation on patterns of small intestinal motility. To avoid confounding effects of immune rejection or immunosuppression, we developed a model of autotransplantation in which all tissue connections to the entire jejunoileum were transected at the base of the mesentery except for the superior mesenteric artery and vein which were stripped meticulously of investing adventitia. After 3 weeks, motility was studied in eight dogs with intestinal electrodes during fasting, after meals of 50 and 500 g of liver, and during intravenous infusions of pentagastrin and cholecystokinin. During fasting, the characteristic inter-digestive migrating motor complex (MMC) was present in both the innervated duodenum and the "autotransplanted" jejunoileum; however, temporal coordination between the two regions was abolished. Feeding 50 g of liver abolished the MMC in the duodenum, but not in the jejunoileum; in contrast, 500 g of liver interrupted the MMC in both regions. Exogenous pentagastrin and cholecystokinin inhibited the MMC for the duration of the infusions. These findings suggest that extrinsic nerves and/or intrinsic (enteric) myoneural continuity do not initiate fasting motor patterns in the jejunoileum but do regulate the temporal coordination of motor patterns between segments of small intestine. Postprandial inhibition of the MMC is only in part mediated by neural factors. After transplantation, motility is abnormal; the overall effects on enteric physiology remain unknown.